ALBERT

Description:    A synthetic route is described here for novel peptide-cellulose conjugates containing O -phospho- l -serine. First, Boc-Ser(PO 3 Ph 2 ) and the related dipeptides, Boc-Ser(PO 3 Ph 2 )-Asp(OBzl) and Boc-Asp(OBzl)-Ser(PO 3 Ph 2 ), were synthesized by adopting the phosphoryl-protection strategy. The condensation reaction between the α -carboxyl group of the protected Boc-Ser(PO 3 Ph 2 ) and the β -amino groups of β -Ala-Cellulose using isobutyl chloroformate and N -methylmorpholine yielded the product conjugate, N β -[Boc-Ser(PO 3 Ph 2 )]- β -Ala-Cellulose. The degree of substitution of Boc-Ser(PO 3 Ph 2 ) towards the β -amino groups of β -Ala-Cellulose was estimated as DS N  = 0.75 (maximum, 1.0). Similar reactions between β -Ala-Cellulose and two kinds of protected dipeptides, Boc-Asp(OBzl)-Ser(PO 3 Ph 2 ) and Boc-Ser(PO 3 Ph 2 )-Asp(OBzl), gave the corresponding conjugates, and the DS N was estimated to be 0.95 and 0.69, respectively. The phenyl, benzyl, and Boc groups were removed in one-pot using the Pt 2 O catalyst in 50 % trifluoroacetic acid/acetic acid. The 31 P-NMR and UV–Visible spectra indicated the complete deprotection without any observable elimination of the phosphorylated peptides. Content Type Journal Article Category Original Paper Pages 1-14 DOI 10.1007/s10570-012-9822-1 Authors Kesavan Devarayan, Faculty of Textile Science and Technology, Institute of High Polymer Research, Shinshu University, Tokida 3-15-1, Ueda, 386-8567 Japan Masakazu Hachisu, Research Institute of Genome-based Biofactory, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1, Tsukisamu-higashi, Toyohira-ku, Sapporo, 062-8517 Japan Jun Araki, Division of Chemistry and Materials, Faculty of Textile Science and Technology, Shinshu University, Tokida 3-15-1, Ueda, 386-8567 Japan Kousaku Ohkawa, Faculty of Textile Science and Technology, Institute of High Polymer Research, Shinshu University, Tokida 3-15-1, Ueda, 386-8567 Japan Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Well soluble dextran-, cellulose-, starch-, and pullulan aryl carbonates were synthesized applying p -NO 2 -phenyl chloroformate, phenyl chloroformate, and phenyl fluoroformate. Aminolysis of the products obtained, using aliphatic amines or benzyl amines, yield novel soluble polysaccharide carbamates. The influence of the reaction conditions on the reaction efficiency depending on polysaccharide, reagent, and reaction parameters including temperature was studied. Thus a synthesis strategy was developed for the easy and efficient design of structures of polysaccharide-based materials. The products were characterized by means of NMR-, UV-Vis- and FTIR spectroscopy, elemental analysis, and size exclusion chromatography. Content Type Journal Article Category Original Paper Pages 1-15 DOI 10.1007/s10570-012-9819-9 Authors Thomas Elschner, Center of Excellence for Polysaccharide Research, Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University of Jena, Humboldtstraße 10, 07743 Jena, Germany Kristin Ganske, Center of Excellence for Polysaccharide Research, Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University of Jena, Humboldtstraße 10, 07743 Jena, Germany Thomas Heinze, Center of Excellence for Polysaccharide Research, Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University of Jena, Humboldtstraße 10, 07743 Jena, Germany Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Flexible composite films were produced by impregnating aqueous phenol formaldehyde (PF) resin into water-swollen cellulose nanofibril (CNF) films. CNF films were prepared using a pressurized filtration method in combination with freeze drying. The freeze-dried films were swollen with water then impregnated with PF resin by soaking in aqueous resin solutions of varying concentrations. Small amounts of PF slightly enhanced the tensile properties of CNF films. The formulation with the best mechanical properties was CNF/PF films with 8 wt % resin exhibiting tensile stress and toughness of 248 MPa and 26 MJ/m 3 , respectively. Resin concentrations higher than about 8 % resulted in composites with decreased tensile properties as compared to neat CNF films. The wet strength of the composite films was significantly higher than that of the neat CNF films. The resulting composites showed greater resistance to moisture absorption accompanied by reduced thickness swelling when soaked in water as compared to neat CNF films. The composites also showed decreased oxygen permeability at low humidity compared to neat films, but the composites did not show improved barrier properties at high humidity. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10570-012-9815-0 Authors Yan Qing, School of Materials Science and Engineering, Central South University of Forestry and Technology, 498 Shaoshan South Road, Changsha, 410004 China Ronald Sabo, Forest Products Laboratory, United States Department of Agriculture, 1 Gifford Pinchot Drive, Madison, 53726-2398 WI, USA Zhiyong Cai, Forest Products Laboratory, United States Department of Agriculture, 1 Gifford Pinchot Drive, Madison, 53726-2398 WI, USA Yiqiang Wu, School of Materials Science and Engineering, Central South University of Forestry and Technology, 498 Shaoshan South Road, Changsha, 410004 China Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Hydrorepellency was conferred to cotton fabrics by an hybrid organic–inorganic finishing via sol–gel. The nanosol was prepared by co-hydrolysis and condensation of tetraethoxysilane (TEOS) and 1H,1H,2H,2H–fluorooctyltriethoxysilane (FOS), or hexadecyltrimethoxysilane (C 16 ), as precursors in weakly acid medium. The application on cotton was carried out by padding with various impregnation times, followed by drying and thermal treatment, varying the FOS add-on from 5 till 30 % on fabric weight or C 16 add-on from 5 to 10 %. Treated samples were tested in terms of contact angles, drop absorption times, washing fastness and characterized by SEM, XPS and FTIR-ATR analyses. In the case of FOS modified nanosol applied with an impregnation time of 24 h or C 16 modified nanosol, water contact angles values very close or even higher than 150° were measured, typical of a superhydrophobic surface. The application of the proposed sol–gel process yielded also a satisfactory treatment fastness to domestic washing, in particular for FOS modified nanosol. Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10570-012-9821-2 Authors Monica Periolatto, Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Turin, Italy Franco Ferrero, Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Turin, Italy Alessio Montarsolo, CNR ISMAC, Istituto per lo Studio delle Macromolecole, C.so Pella 16, 13900 Biella, Italy Raffaella Mossotti, CNR ISMAC, Istituto per lo Studio delle Macromolecole, C.so Pella 16, 13900 Biella, Italy Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Transparent and water repellent gas barrier cellulose films were fabricated by surface modification of alkali/urea regenerated cellulose (AUC) films by soaking in cationic alkylketene dimer (AKD) dispersion, drying, and heating. Highly water repellent and excellent gas barrier properties were obtained for AKD-treated and heated AUC films due to covering of the film surfaces by hydrophobic AKD components. The maximum AKD content of the films was 0.2 %. Oxygen transmission rates for AKD-treated AUC films at 0 % relative humidity (RH) were less than 0.0005 mL m −2 day −1 kPa −1 , the lowest detection limit of the instrument. Water contact angles on the AUC film increased from 50 to 110° after AKD treatment, and water uptake (immersion in water for 6 days) decreased from 92 to 20 %. Moreover, oxygen permeability decreased from 0.56 and 5.8 to 0.13 and 2.1 mL μm m −2 day −1 kPa −1 at 50 and 75 % RH, respectively, when the AKD content of the film was increased from 0 to 0.2 %. The present AKD-treated AUC film also had high light transparency (88 % at 600 nm), tensile strength (168 MPa), elongation at break (29 %), and work of fracture (37 MJ m −3 ). FT–IR analysis showed that AKD components were still present as major species on the AKD-treated film surfaces without hydrolysis at 2 months after conditioning the films at 23 °C and 50 % RH, indicating that such AKD molecules contributed to the hydrophobic nature of the AKD-treated AUC films. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10570-012-9790-5 Authors Quanling Yang, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657 Japan Tsuguyuki Saito, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657 Japan Akira Isogai, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657 Japan Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Unbleached (UN), oxygen-delignified and fully-bleached (FB) birch fibers with a residual lignin content of ca. 3, 2 and 〈1 %, respectively, were used to produce nanofibrillated cellulose (NFC) and nanopaper by using an overpressure device. The tensile index, elongation and elastic modulus of nanopaper were compared and the effect of residual cell wall components accessed. Under similar manufacturing conditions, UN NFC produced nanopaper with a density of 0.99 g/cm 3 , higher than that from FB NFC (0.7 g/cm 3 ). This translated in much lower air permeability in the case of UN nanopaper (1 and 11 mL/min for UN and FB samples, respectively). Fundamentally, these observations are ascribed to the finer fibrils produced during microfluidization of UN fibers compared to those from lower yield counterparts (AFM roughness of 8 and 17 nm and surface areas of 124 and 98 m 2 /g for NFC from UN and FB fibers, respectively). As a result, values of stress at break and energy absorption of nanopaper from high yield fibers are distinctively higher than those from fully bleached NFC. Interactions of water with the surface and bulk material were affected by the chemical composition and structure of the nanofibrils. While UN nanopaper presented higher water contact angles their sorption capacity (and rate of water absorption) was much higher than those measured for nanopaper from FB NFC. These and other observations provided in this contribution are proposed to be related to the mechanoradical scavenging capacity of lignin in high shear microfluidization and the presence of residual heteropolysaccharides. Content Type Journal Article Category Original Paper Pages 1-15 DOI 10.1007/s10570-012-9788-z Authors Ana Ferrer, Department of Chemical Engineering, University of Cordoba, Cordoba, Spain Elisabet Quintana, Textile and Paper Engineering Department, Universitat Politècnica de Catalunya, 08222 Terrassa, Spain Ilari Filpponen, School of Chemical Technology, Department of Forest Products Technology, Aalto University, 00076 Aalto, Finland Iina Solala, School of Chemical Technology, Department of Forest Products Technology, Aalto University, 00076 Aalto, Finland Teresa Vidal, Textile and Paper Engineering Department, Universitat Politècnica de Catalunya, 08222 Terrassa, Spain Alejandro Rodríguez, Department of Chemical Engineering, University of Cordoba, Cordoba, Spain Janne Laine, School of Chemical Technology, Department of Forest Products Technology, Aalto University, 00076 Aalto, Finland Orlando J. Rojas, School of Chemical Technology, Department of Forest Products Technology, Aalto University, 00076 Aalto, Finland Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Bacterial cellulose (BC) membranes were modified with oxygen (O 2 ), nitrogen (N 2 ), and tetrafluoromethane (CF 4 ) plasmas in order to enhance cell affinity. The surface properties of the pristine and plasma-treated BCs were analyzed through water contact angles, electron spectroscopy for chemical analysis (ESCA), and scanning electron microscopy. O 2 and N 2 plasmas changed the surface of BCs to more hydrophilic while CF 4 plasma altered BCs to be very hydrophobic. ESCA analyses indicated that O 2 , N 2 , and CF 4 plasmas incorporated the functionalities of carbon–oxygen, amides and amino, and carbon-fluoride on BCs, respectively. The effects of the plasma treatments on the adhesion of L-929 fibroblast and Chinese hamster ovary cell lines showed that the cell adhesion and proliferation of both cells was significantly improved on BC-CF 4 , in contrast with that on the pristine BC, BC-O 2 , and BC-N 2 , revealing a functionality-specific effect resulted from different plasmas. Moreover, protein adsorption tests indicated that a higher quantity of proteins in cell culture medium was adsorbed on the CF 4 plasma-treated BCs which presumably played the role of enhancing the subsequent cell growth. This work highlights the great potential of plasma treatments on the improvement of biocompatibility and surface property of BCs for biomedical applications. Content Type Journal Article Category Original Paper Pages 1-14 DOI 10.1007/s10570-012-9785-2 Authors Hengky Kurniawan, Department of Chemical Engineering, National Taiwan University of Science and Technology, 43, Keelung Rd., Sec. 4, Taipei, 106 Taiwan Jinn-Tsyy Lai, The Food Industry Research and Development Institute (FIRDI), 331 Shih-Pin Road, Hsinchu, 300 Taiwan Meng-Jiy Wang, Department of Chemical Engineering, National Taiwan University of Science and Technology, 43, Keelung Rd., Sec. 4, Taipei, 106 Taiwan Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Fe 3 O 4 /chitosan/poly(acrylic acid) (Fe 3 O 4 /CS/PAA) composite particles, which are reusable, biodegradable and of high adsorption capacity, have been prepared through polymerizing acrylic acid in chitosan and Fe 3 O 4 nanoparticles aqueous solution. By varying in-feed mole ratio of carboxyl to amino group (n c /n a ) and reactant concentration, the average diameter of Fe 3 O 4 /CS/PAA composite particles can be controlled to vary from 100 to 300 nm. FT-IR, XRD and TEM were used to characterize Fe 3 O 4 /CS/PAA composite particles. Results showed that Fe 3 O 4 was indeed incorporated into CS/PAA particles. The composite particles showed high efficient to remove copper ions (II) in aqueous solution. Adsorption kinetic studies showed that the adsorption process followed a pseudo-second-order kinetic model and the equilibrium data agreed well with the Langmuir model. The saturated adsorption capacity obtained from the experimental was 193 mg/g in close to proximity to the data 200 mg/g calculated from Langmuir model. The saturated adsorption capacity still retained 100 mg/g after three cycles of adsorption–desorption of copper ions (II). Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10570-012-9783-4 Authors Sai Zhang, Anhui Province Key Laboratory of Environment-friendly Polymer Materials, College of Chemistry and Chemical Engineering, Anhui University, Hefei, 230039 People’s Republic of China YiFeng Zhou, Anhui Province Key Laboratory of Environment-friendly Polymer Materials, College of Chemistry and Chemical Engineering, Anhui University, Hefei, 230039 People’s Republic of China WangYan Nie, Anhui Province Key Laboratory of Environment-friendly Polymer Materials, College of Chemistry and Chemical Engineering, Anhui University, Hefei, 230039 People’s Republic of China LinYong Song, Anhui Province Key Laboratory of Environment-friendly Polymer Materials, College of Chemistry and Chemical Engineering, Anhui University, Hefei, 230039 People’s Republic of China Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Seven varieties of flax ( Linum usitatissimum ) fibres were analyzed in order to gain a deeper insight into the morphological features of the crystalline assembly. Different spectroscopic techniques and a chemical bleaching process were used to provide an accurate description of the lateral arrangement of the polysaccharide chains within the fibre cell wall. The flax fibres were analyzed in their natural state and after an extraction treatment of the non-crystalline components such as hemicelluloses, pectins and phenolics. The chemical bleaching process consisted of a Soxhlet extraction in toluene, a sodium chlorite treatment and an alkaline extraction of the residual hemicelluloses. Solid-state 13 C nuclear magnetic resonance (NMR) confirmed the sequential removal of the non-cellulosic components from the flax cell wall. Both wide-angle X-ray diffraction (WAXD) and solid-state 13 C NMR provided measures of the crystallite thicknesses and overall crystallinities before and after treatment. The existence of non-cellulosic highly ordered paracrystalline domains was also evidenced by proton spin relaxation time calculation. Whereas the overall crystallinity determined by WAXD decreased after treatment, the cellulose crystallinity calculated with the help of the solid-state 13 C NMR slightly increased. This is explained by the difference in chemical selectivity between these two techniques and by the paracrystalline state of both hemicelluloses and pectins. Strong adhesion between cellulose crystallites, hemicelluloses and pectins in the fibres was evidenced by low spin–spin relaxation times and by an increase in crystallite thickness after bleaching. A simple model is proposed that describes the rearrangement of the macromolecules during the bleaching process. Content Type Journal Article Category Original Paper Pages 1-18 DOI 10.1007/s10570-012-9786-1 Authors Benoît Duchemin, LOMC, UMR 6294, CNRS-Université du Havre, 53 rue Prony, 76058 Le Havre, France Anthony Thuault, LOMC, UMR 6294, CNRS-Université du Havre, 53 rue Prony, 76058 Le Havre, France Aurélie Vicente, Laboratoire Catalyse et Spectrochimie (LCS), ENSICAEN, Université de Caen, CNRS, 14050 Caen, France Baptiste Rigaud, Laboratoire Catalyse et Spectrochimie (LCS), ENSICAEN, Université de Caen, CNRS, 14050 Caen, France Christian Fernandez, Laboratoire Catalyse et Spectrochimie (LCS), ENSICAEN, Université de Caen, CNRS, 14050 Caen, France Sophie Eve, Laboratoire de Cristallographie et de Sciences des Matériaux, ENSICAEN, Université de Caen, CNRS, 14050 Caen, France Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Chemical surface modification of nanofibrillated cellulose (NFC) was performed using a long aliphatic isocyanate chain. Different molar ratios of the coupling agents were tested, i.e., 1, 10, 30 equivalents with respect to hydroxyl groups of the NFC surface. FE-SEM analyses revealed that there were no changes in their morphology thus keeping nanofibril-like structure with about 30 nm of diameter. All these samples were characterized by different techniques (e.g., FTIR) to check the efficiency of the grafting. Hydrophobic NFC were achieved whatever the grafting agent ratio. The Degree of Substitution was determined by Elemental Analyses and the Degree of Substitution of the Surface was calculated thanks to X-ray Photoelectron Spectroscopy data. Combining these two techniques, the Internal Degree of Substitution was proposed for the first time. It indicates if the modification occurs also within NFC internal layers. Surface (contact angle), rheological (water suspension viscosity) and thermal properties (ThermoGravimetric Analysis) of grafted NFC do not follow the expected linear evolution of properties with the increase of molar ratio. X-Ray Diffraction analyses showed that the grafted aliphatic chains display crystalline waxy domains at some ratios. A model for aliphatic chain organization at the surface is proposed and clearly explained for the first time why a compromise in molar ratio is necessary to achieve best properties. Content Type Journal Article Category Original Paper Pages 1-17 DOI 10.1007/s10570-012-9780-7 Authors Karim Missoum, Laboratory of Pulp and Paper Science (LGP2), 461, rue de la papeterie, BP65, 38402 St-Martin-d’Hères Cedex, France Julien Bras, Laboratory of Pulp and Paper Science (LGP2), 461, rue de la papeterie, BP65, 38402 St-Martin-d’Hères Cedex, France Mohamed Naceur Belgacem, Laboratory of Pulp and Paper Science (LGP2), 461, rue de la papeterie, BP65, 38402 St-Martin-d’Hères Cedex, France Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Gold nanoparticles were synthesized on the surface of natural fique fibers extracted from the leaves of Furcraea spp., a plant native to the Andean mountains in Colombia. Fique fibers have a low density, are biodegradable, flexible, highly resistant to wear and exhibit excellent thermal degradation making them promising materials for the textile and packing industries as well as fillers for fiber-reinforced composites. Fique fiber surface was rendered positive using a cationizing agent 3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CHTAC) under strong alkaline conditions. Cationic fique fibers were impregnated with an anionic gold complex that was further reduced to generate gold nanoparticles onto the fibers surface. The influence of CHTAC reaction times and NaOH:CHTAC molar ratios were examined. It was found that increasing the NaOH:CHTAC molar ratio had a negligible effect on nanoparticle size, while the surface coverage density was positively influenced. We hypothesize that the number of positive charges on the fiber surface is the key factor behind this observation. UV–Vis diffuse reflectance spectroscopy; mechanical tests and field emission scanning electron microscopy were used to characterize the modified fibers and the resulting nanoparticles. The proposed method opens a new path for the development of functional natural renewable substrates. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10570-012-9763-8 Authors L. J. Castellanos, Escuela de Química, Universidad Industrial de Santander, A.A. 678, Bucaramanga, Colombia C. Blanco-Tirado, Escuela de Química, Universidad Industrial de Santander, A.A. 678, Bucaramanga, Colombia J. P. Hinestroza, Fiber Science Program, Cornell University, Ithaca, NY 14850, USA M. Y. Combariza, Escuela de Química, Universidad Industrial de Santander, A.A. 678, Bucaramanga, Colombia Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    N,N -Dimethylacetamide/lithium chloride (DMAc/LiCl) mixture is a popular solvent system used for cellulose dissolution, analysis, and derivatization. However, a pre-treatment (activation) procedure is needed for most celluloses to dissolve readily in DMAc/LiCl. Here, an optimized version of the activation protocol based on solvent exchange to 1,4-dioxane was introduced. Its universality was demonstrated by successful activation and dissolution of six different celluloses (AVICEL, Sigmacell, cotton linters, Encell, Lincell, and Whatman paper). Dissolution times varied significantly for different cellulose types and also depended on factors such as the drying method employed or the water removal step inclusion/omission. Dioxane-activated celluloses were analyzed with a variety of methods. SEC measurements indicated low destructivity of the dioxane activation method. The infrared spectroscopy analysis showed that dioxane remained adsorbed on cellulose even after rigorous drying. In addition, upon dioxane activation, stagnation or a slight increase in the total order index of celluloses was observed. This observation was in accordance with the crystallinity index changes determined by solid-state NMR. Finally, scanning electron microscopy revealed disintegration of AVICEL particles and defibrillation of fibrous celluloses upon dioxane activation; Sigmacell remained apparently unchanged. Content Type Journal Article Category Original Paper Pages 1-14 DOI 10.1007/s10570-012-9779-0 Authors Vladimír Raus, Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2, 162 06 Prague 6, Czech Republic Adriana Šturcová, Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2, 162 06 Prague 6, Czech Republic Jiří Dybal, Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2, 162 06 Prague 6, Czech Republic Miroslav Šlouf, Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2, 162 06 Prague 6, Czech Republic Taťána Vacková, Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2, 162 06 Prague 6, Czech Republic Petr Šálek, Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2, 162 06 Prague 6, Czech Republic Libor Kobera, Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2, 162 06 Prague 6, Czech Republic Petr Vlček, Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2, 162 06 Prague 6, Czech Republic Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    The preparation of high-strength hydrogels from plant-based cellulose nanofibers by simple alkaline treatment is described herein. We isolated the cellulose nanofibers with a uniform width of approximately 15 nm from wood and we prepared two types of hydrogel sheet with different crystal forms (celluloses I and II) in 9 and 15 wt% aqueous sodium hydroxide solutions. Both of the hydrogels exhibited high tensile properties because of the crystalline network in the gels. Especially, the nanofiber hydrogel with a cellulose II crystal structure with the swelling degree of 13.4 achieved a Young’s modulus and tensile strength in excess of 35 and 5 MPa respectively, because it had a continuous and strong nano-network formed via the interdigitation of the neighboring nanofibers during mercerization. Content Type Journal Article Category Original Paper Pages 1-6 DOI 10.1007/s10570-012-9784-3 Authors Kentaro Abe, Research Institute for Sustainable Humanosphere, Kyoto University, Gokasyo, Uji, Kyoto, 611-0011 Japan Hiroyuki Yano, Research Institute for Sustainable Humanosphere, Kyoto University, Gokasyo, Uji, Kyoto, 611-0011 Japan Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    The effect of urea on the cellulose degradation under conditions of alkaline pulping has been studied using purified cellulose powder. The increased cellulose yield in the presence of urea was assigned essentially to the carbamation reactions which were confirmed by elemental analysis, UV-resonance Raman and solid-state 13 C nuclear magnetic resonance spectroscopy. The stabilizing effect of urea on the cellulose peeling reactions during heating up period of pulping process was suggested based on kinetic studies and additionally confirmed in model reactions using cellobiose. The reaction products formed in alkaline urea solutions were analysed by tandem electrospray ionization mass spectrometry and the occurrence of Maillard type reactions between reducing end groups of cellobiose and urea were evidenced. Both Maillard type reactions and carbamation of reducing end groups were proposed to be a part of cellulose protection mechanism against peeling under the conditions of alkaline pulping. Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10570-012-9791-4 Authors Olga Ershova, Department of Forest Products Technology, School of Chemical Technology, Aalto University, P.O. Box 16300, 00076 Espoo, Finland Elisabete V. da Costa, CICECO/QOPNA, Chemistry Department, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal António J. S. Fernandes, I3N, Department of Physics, University of Aveiro, 3810-193 Aveiro, Portugal M. Rosário Domingues, CICECO/QOPNA, Chemistry Department, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal Dmitry V. Evtuguin, CICECO/QOPNA, Chemistry Department, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal Herbert Sixta, Department of Forest Products Technology, School of Chemical Technology, Aalto University, P.O. Box 16300, 00076 Espoo, Finland Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    The flame retardancy properties of cotton have been enhanced by exploiting an optimized multistep sol–gel process, consisting of a pre-hydrolysis step, followed by consecutive depositions of hybrid phosphorus-doped silica layers, using DPTS as precursor of the oxidic phases. Upon optimization, it has been demonstrated that just one phosphorus-doped silica layer is able to strongly reduce the heat release rate (−52 %), and the total smoke release (−56 %) and its rate (−62 %) with respect to the untreated fabric. In addition, the deposition of three layers allows achieving a higher flammability resistance if compared to a single layer, as indicated by the final residue after the flammability tests. As far as flammability resistance is concerned, the new coatings have shown a good durability when subjected up to five washing cycles according to ISO 6330 standard. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10570-012-9806-1 Authors Jenny Alongi, Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, sede di Alessandria and local INSTM unit, Viale Teresa Michel 5, 15121 Alessandria, Italy Claudio Colleoni, Dipartimento di Ingegneria Industriale, Università di Bergamo, Viale Marconi 5, 24044 Dalmine, Bergamo, Italy Giuseppe Rosace, Dipartimento di Ingegneria Industriale, Università di Bergamo, Viale Marconi 5, 24044 Dalmine, Bergamo, Italy Giulio Malucelli, Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, sede di Alessandria and local INSTM unit, Viale Teresa Michel 5, 15121 Alessandria, Italy Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Cellulose nanowhiskers (CNWs) were chemically modified by acetylating to obtain acetylated cellulose nanowhiskers (ACNWs) which could be well dispersed in acetone. The chemical modification was limited only on the surface of CNWs which was confirmed by transmission electron microscopy (TEM) and X-ray diffraction (XRD). Surface substitution degree of ACNWs was evaluated to be 0.45 through X-ray photoelectron spectroscopy (XPS). Fully bioresource-based nanocomposite films were manufactured by incorporation of ACNWs into cellulose acetate (CA) using a casting/evaporation technique. Scanning electron microscope (SEM) demonstrated that ACNWs dispersed well in the CA matrix, which resulted in high transparency of all CA nanocomposites. The tensile strength, Young’s modulus and strain at break of all CA nanocomposites exhibited simultaneous increase in comparison with neat CA matrix. At the content of 4.5 wt% ACNWs, the tensile strength, Young’s modulus and strain at break of the CA nanocomposite film were increased by 9, 39, and 44 % respectively. Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10570-012-9796-z Authors Zhen-Yu Yang, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, China Wen-Jun Wang, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, China Zi-Qiang Shao, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, China Hai-Dong Zhu, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, China Yong-Hong Li, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, China Fei-Jun Wang, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, China Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    We describe the synthesis, characterization and use of a composite material made of a renewable source and metallic nanoparticles for biosensing applications. Nanocrystalline cellulose (NCC) is a product isolated from natural cellulose fibers, which is of approximately 100 nm long and 10 nm wide in size. We augmented the surface area and tailored the chemical affinity of NCC by optimally dressing it with gold nanoparticles (AuNPs). The deposition of AuNPs on NCC was controlled by using cationic polyethylenimine (PEI) at different pHs. AuNPs were thiol-functionalized using different linkers prior to enzyme immobilization. The enzyme (glucose oxidase or GOx) was conjugated on the composite by carbodiimide coupling, and subsequent activation of linker-carboxylic acid group. Our results showed that GOx was attached to the surface of the NCC nanocomposite. Moreover, the amount of GOx loaded onto the support depended on the length of the thiol-linker used. The lower value (20.3 mg/mg of support) was obtained with the longer thiol-linker (11 carbon chain) compared to 25.2 mg/mg of support for the smaller thiol-linker (3 carbon chain). Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10570-012-9805-2 Authors Vanessa Incani, National Institute for Nanotechnology, National Research Council Canada, Edmonton, T6G 2M9 Canada Christophe Danumah, National Institute for Nanotechnology, National Research Council Canada, Edmonton, T6G 2M9 Canada Yaman Boluk, Department of Civil and Environmental Engineering, University of Alberta, Edmonton, T6G 2M2 Canada Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    The chemical structure of rye arabinoxylan (rAX) was systematically modified, exploiting selective enzymes to mimic different naturally occurring xylans, i.e., its degree of substitution (DS) was decreased using α- l -arabinofuranosidase, and a controlled decrease in the degree of polymerization (DP) was performed using endo-1,4-β- d -xylanase. The arabinose to xylose ratio was decreased from 0.45 to 0.27 and the weight-average molar mass was decreased from 184,000 to 49,000 g/mol. The resulting samples were used to prepare films, as such, and with 15% (wt. − %) softwood-derived microfibrillated cellulose (MFC) to obtain novel plant-derived biocomposite materials. The enzymatic tailoring of rAX increased the crystallinity of films, evidenced by X-ray diffraction studies, and the addition of MFC to the debranched, low DS rAX induced the formation of ordered structures visible with polarizing optical microscopy. MFC decreased the moisture uptake of films and increased the relative humidity of softening of the films, detected with moisture scanning dynamic mechanical analysis. For the first time, the chemical structure of xylan was proven to significantly affect the reinforcement potential of nano-sized cellulose, as the tensile strength of films from high DP rAXs, but not that of low DP rAXs, clearly increased with the addition of MFC. At the same time, MFC only increased the Young’s modulus of films from rAX with high arabinose content, regardless of DP. Content Type Journal Article Pages 467-480 DOI 10.1007/s10570-012-9655-y Authors Kirsi S. Mikkonen, Department of Food and Environmental Sciences, University of Helsinki, P.O. Box 27, 00014 Helsinki, Finland Leena Pitkänen, Department of Food and Environmental Sciences, University of Helsinki, P.O. Box 27, 00014 Helsinki, Finland Ville Liljeström, Department of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki, Finland Elina Mabasa Bergström, INNVENTIA AB, Fibre & Material Science, Box 5604, 114 86 Stockholm, Sweden Ritva Serimaa, Department of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki, Finland Lennart Salmén, INNVENTIA AB, Fibre & Material Science, Box 5604, 114 86 Stockholm, Sweden Maija Tenkanen, Department of Food and Environmental Sciences, University of Helsinki, P.O. Box 27, 00014 Helsinki, Finland Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239 Journal Volume Volume 19 Journal Issue Volume 19, Number 2

Description:    We prepared two cellulose hydrates, Na-cellulose IV and cellulose II hydrate, along with their respective anhydrous forms, cellulose II and II′, from microcrystalline cellulose. X-ray diffractometry analysis showed that the structure of the hydrophobic stacking sheet was conserved in the samples, but the distance between the sheets was in the order: cellulose II hydrate 〉 Na-cellulose IV 〉 cellulose II and II′. The hydrates exhibited an expanded structure compared with the anhydrous form from the incorporation of hydrate water, and cellulose II hydrate contained more hydrate water than Na-cellulose IV. Enzymatic hydrolysis of the samples was carried out at 37 °C using solutions comprising a mixture of cellulase and β-glucosidase. The hydrates were hydrolyzed more efficiently than the anhydrous forms, and cellulose II hydrate showed a more efficient hydrolysis than Na-cellulose IV. This result also agrees well with the enzymatic adsorption properties of each sample, where the samples that adsorbed the greater amount of enzyme showed a higher degradability. The results obtained in this study provide useful knowledge on controlling the biodegradability of cellulose by converting its structure. Content Type Journal Article Category Original Paper Pages 1-8 DOI 10.1007/s10570-012-9696-2 Authors Kayoko Kobayashi, Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657 Japan Satoshi Kimura, Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657 Japan Ung-Jin Kim, Department of Plant and Environmental New Resources, College of Life Sciences, Kyung Hee University, 1, Seocheon-dong, Giheung-ku, Yongin-si, Gyeonggi-do 446-701, Republic of Korea Ken Tokuyasu, Food Resource Division, National Food Research Institute, National Agriculture and Food Research Organization, 2-1-12 Kannondai, Tsukuba, Ibaraki, 305-8642 Japan Masahisa Wada, Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657 Japan Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    A novel hydrogel has synthesized by grafting polyacrylamide chains onto hydroxypropyl methylcellulose in presence of potassium persulphate as initiator using solution polymerization technique. The reaction was carried out in homogeneous aqueous medium. The effect of reaction parameters on percentage of grafting (% G) and grafting efficiency (% GE) were discussed. The parameters were varied systematically to achieve the best hydrogel. Developed hydrogels were characterized by various materials characterization techniques. The dynamic and equilibrium swelling properties of hydrogels were investigated as a function of pH and time in various buffer solutions similar to that of gastric and intestinal fluid. Results showed that with increase in % G and % GE, the rate of swelling decreases, which can opens the door for further study of their utilization as matrices for controlled/sustained/targeted drug delivery. Content Type Journal Article Category Original Paper Pages 1-13 DOI 10.1007/s10570-012-9692-6 Authors R. Das, Polymer Chemistry Laboratory, Department of Applied Chemistry, Indian School of Mines, Dhanbad, 826004 India A. B. Panda, Disciplines of Inorganic Materials and Catalysis, CSMCRI, Bhavnagar, 364021 India Sagar Pal, Polymer Chemistry Laboratory, Department of Applied Chemistry, Indian School of Mines, Dhanbad, 826004 India Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Bacterial cellulose was oxidized by periodate oxidation to give rise to 2,3-dialdehyde bacterial cellulose (DABC) with 60.3 ± 0.5 % aldehyde content, which was further reacted with gelatin (Gel) for the immobilization of Gel to form DABC/Gel nanocomposites. The scanning electron microscopy and transmission electron microscopy revealed that DABC/Gel exhibited the refined 3D nano-network structures and the average thickness of Gel coatings in the composites was about 75 nm. FTIR and XPS were utilized to analyze the functional groups and chemical states of DABC/Gel nanocomposites. The results inferred that Gel was fixed on DABC nanofibers via the Schiff base reaction between –NH 2 in Gel and –CHO in DABC backbone. NIH3T3 mice fibroblast cells were used for determining the cytocompatibility of the scaffolds. The morphology of the cells was observed through optical inverted microscopy. The results show that DABC/Gel can be used as scaffold material in tissue engineering. Content Type Journal Article Category Original Paper Pages 1-8 DOI 10.1007/s10570-012-9698-0 Authors Chuan Gao, School of Materials Science and Engineering, Tianjin University, 300072 Tianjin, People’s Republic of China Tao Yan, Department of Pharmacy Servic, Tianjin Huanhu Hospital, 300060 Tianjin, People’s Republic of China Kerong Dai, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences and Shanghai JiaoTong University School of Medicine, 200025 Shanghai, People’s Republic of China Yizao Wan, School of Materials Science and Engineering, Tianjin University, 300072 Tianjin, People’s Republic of China Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    3-Allyloxy-2-hydroxypropylcelluloses (AHP-celluloses), reactive unsaturated cellulose derivatives, were homogeneously synthesized by the reaction of cellulose with allyl glycidyl ether (AGE) in NaOH/urea aqueous solution. Water-soluble AHP-celluloses with DS NMR  = 0.32–0.67 were prepared from microcrystalline cellulose. The degree of substitution (DS) of AHP-celluloses could be controlled by varying the molar ratio of AGE and NaOH to AGU and the reaction conditions. The structure of AHP-cellulose samples were characterized by means of FT-IR, NMR spectroscopy and size exclusion chromatography. The cellulose ether shows thermoreversible flocculation. Bromination reactions were carried out as subsequent functionalization both to illustrate the reactivity of the allyl function and to determine the DS values. Content Type Journal Article Category Original Paper Pages 1-8 DOI 10.1007/s10570-012-9687-3 Authors Haisong Qi, Institute of Organic Chemistry and Macromolecular Chemistry, Centre of Excellence for Polysaccharide Research, Friedrich Schiller University of Jena, Humboldtstraße 10, 07743 Jena, Germany Tim Liebert, Institute of Organic Chemistry and Macromolecular Chemistry, Centre of Excellence for Polysaccharide Research, Friedrich Schiller University of Jena, Humboldtstraße 10, 07743 Jena, Germany Thomas Heinze, Institute of Organic Chemistry and Macromolecular Chemistry, Centre of Excellence for Polysaccharide Research, Friedrich Schiller University of Jena, Humboldtstraße 10, 07743 Jena, Germany Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    The morphology and crystalline structure changes of cellulose during dissolution in 1-butyl-3-methylimidazolium chloride [(BMIM)Cl] were investigated by optical microscopy and synchrotron radiation wide-angle X-ray diffraction (WAXD). Neither swelling nor dissolution of cellulose was observed under the melting point of [BMIM]Cl. While the temperature was elevated to 70 °C, the swelling phenomenon of cellulose happened with the interplanar spacing of ( 1 - 1   0 ) and (020) planes increased slightly. With the temperature further going up to 80 °C, cellulose was dissolved gradually with the crystallinity ( W c,x ) and crystalline index ( CrI ) of cellulose decreased rapidly, which indicated the crystalline structure of cellulose was destroyed completely and transformed into amorphous structure. Content Type Journal Article Category Original Paper Pages 1-7 DOI 10.1007/s10570-012-9689-1 Authors Guansen Jiang, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, 201620 China Weifeng Huang, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, 201620 China Baochun Wang, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, 201620 China Yumei Zhang, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, 201620 China Huaping Wang, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, 201620 China Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    The hypothesis advanced in this issue of CELLULOSE [Springer] by Bjorn Lindman, which asserts that the solubility or insolubility characteristics of cellulose are significantly based upon amphiphilic and hydrophobic molecular interactions, is debated by cellulose scientists with a wide range of experiences representing a variety of scientific disciplines. The hypothesis is based on the consideration of some fundamental polymer physicochemical principles and some widely recognized inconsistencies in behavior. The assertion that little-recognized (or under-estimated) hydrophobic interactions have been the reason for a tardy development of cellulose solvents provides the platform for a debate in the hope that new scientific endeavors are stimulated on this important topic. Content Type Journal Article Category Review Pages 1-10 DOI 10.1007/s10570-012-9691-7 Authors Wolfgang G. Glasser, Department of Sustainable Biomaterials, Virginia Tech, Blacksburg, VA, USA Rajai H. Atalla, Chem. Biol. Eng., University of Wisconsin, Madison, WI, USA John Blackwell, Department of Macromolecular Science and Engineering, Case Western University, Cleveland, OH, USA R. Malcolm Brown, Plant Cell Biology, University of Texas, Austin, TX, USA Walther Burchard, Institute of Macromolecular Chemistry, University of Freiburg, Freiburg, Germany Alfred D. French, Southern Regional Research Center, ARS-USDA, New Orleans, LA, USA Dieter O. Klemm, Institute of Organic and Macromolecular Chemistry, University of Jena, Jena, Germany Yoshiharu Nishiyama, CERMAV-CNRS, Grenoble, France Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Due to the high potential of cellulose nanoparticles in composite materials and for both fundamental and technological considerations, we investigated the interaction between microfibrillar cellulose and fibers. The contribution to the paper properties of fines added to a pulp suspension was determined. The impact of various proportions of fines added to a softwood kraft pulp on the paper strength and how they affected porosity and density was evaluated. The respective effects of dried fines (dead fines), originating from paper or board degradation, and the newly formed secondary fines (fresh fines) generated during refining were examined. The nature of the bonding between the fines and the fibers versus physical retention was characterized in the pulp suspension. For the first time the respective parts in the interaction of hydrogen bonds and mechanical associations were demonstrated and quantified. The amount of H-bonded fresh fines exceeded that of dead fines by more than 30 %. The results revealed that, for both types, the amount of H-bonded fines reached a threshold, independently of the proportion of fines added to the fibers. Addition of fines significantly affected the porosity of papers, fresh fines decreasing porosity more readily than dead fines. All the results are convergent to indicate that fresh fines penetrate more evenly and more deeply into the fiber network and induce better bonding that produces a closure of the fiber mat structure. They also demonstrate that incorporating an optimal proportion of fresh cellulose fines in fiber networks can bring significant improvement to the final composite material. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10570-012-9693-5 Authors Jean-Paul Joseleau, Centre de Recherches sur les Macromolécules Végétales (CERMAV), CNRS UPR 5301, BP 53, 38041 Grenoble Cedex 9, France Valérie Chevalier-Billosta, Centre de Recherches sur les Macromolécules Végétales (CERMAV), CNRS UPR 5301, BP 53, 38041 Grenoble Cedex 9, France Katia Ruel, Centre de Recherches sur les Macromolécules Végétales (CERMAV), CNRS UPR 5301, BP 53, 38041 Grenoble Cedex 9, France Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Cellulose whiskers were prepared from wood- and cotton-based microcrystalline cellulose and dried by two methods: freeze-drying or air-drying. The effect of drying method on the properties and structure of the whiskers were studied. Furthermore, the influence of the source of cellulose on the nanoscale structure was investigated. Drying method was observed to slightly influence the thermal stability of cellulose whiskers, whereas the char residue varied significantly depending on the drying process performed. Small- and wide-angle X-ray scattering and solid state nuclear magnetic resonance spectroscopy were used to examine the crystallinity and nanoscale structure of the dried whiskers. It was observed that the crystal structure and crystallinity of cellulose whiskers remained during all treatments, whereas their nanoscale structure was significantly influenced by drying method, neutralization, and source of cellulose. Relationships between thermal behavior and nanoscale structure were reported and discussed. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10570-012-9695-3 Authors Pirita Rämänen, Laboratory of Polymer Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, 00014 Helsinki, Finland Paavo A. Penttilä, Division of Materials Physics, Department of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki, Finland Kirsi Svedström, Division of Materials Physics, Department of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki, Finland Sirkka Liisa Maunu, Laboratory of Polymer Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, 00014 Helsinki, Finland Ritva Serimaa, Division of Materials Physics, Department of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki, Finland Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Enhancing the effectiveness of a laccase–TEMPO treatment on sisal pulp by increasing pulp consistency was for the first time found to increase the biorefining potential of this enzyme–mediator system. The operating conditions used were those previously found to maximize oxidative functionalization and paper strength. Prior to the enzyme treatment, the pulp was refined at a variable intensity (0, 3,000 and 4,500 revolutions) in order to ascertain whether the increased surface area would lead to enhanced functionalization and boost the refining effect as a result. Increasing pulp consistency increased the contents in aldehyde and carboxyl groups by 130% and 94%, respectively. Also, it resulted in more marked reduction of pulp viscosity during the enzyme treatment, especially at a high refining intensity; this had a detrimental effect on fibre strength and significantly reduced tear strength in the refined pulp. Oxidized pulp exhibited a considerably increased water retention value with respect to the initial pulp, particularly after refining. Dry tensile index was increased by 21, 18 and 12%, and burst index by 23, 16 and 13% at 0, 3,000 and 4,500 rev, respectively, by the laccase–TEMPO treatment as a result of increased inter-fibre hydrogen bonding offsetting the loss of fibre strength, an effect that can provide substantial savings in refining energy. Based on the results, a laccase–TEMPO treatment is an enzymatic booster of mechanical refining with the added advantages of providing unaltered drainability and increased air permeability. The most salient effect of the laccase–TEMPO treatment was an increase in wet tensile strength (by 160, 553 and 588% at 0, 3,000 and 4,500 rev, respectively) that can be ascribed to inter-fibre covalent bonding through hemiacetal linkages promoted by aldehyde groups. The improvement was much greater than that obtained at a lower consistency under identical conditions. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10570-012-9686-4 Authors Elisabetta Aracri, Textile and Paper Engineering Department, Universitat Politècnica de Catalunya, Colom 11, 08222 Terrassa, Spain Teresa Vidal, Textile and Paper Engineering Department, Universitat Politècnica de Catalunya, Colom 11, 08222 Terrassa, Spain Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Bionanocomposites with improved properties based on two microbial polysaccharides, pullulan and bacterial cellulose, were prepared and characterized. The novel materials were obtained through a simple green approach by casting water-based suspensions of pullulan and bacterial cellulose and characterized by TGA, RDX, tensile assays, SEM and AFM. The effect of the addition of glycerol, as a plasticizer, on the properties of the materials was also evaluated. All bionanocomposites showed considerable improvement in thermal stability and mechanical properties, compared to the unfilled pullulan films, evidenced by the significant increase in the degradation temperature (up to 40 °C) and on both Young’s modulus and tensile strength (increments of up to 100 and 50%, for films without glycerol and up to 8,000 and 7,000% for those plasticized with glycerol). Moreover, these bionanocomposite films are highly translucent and could be labelled as sustainable materials since they were prepared entirely from renewable resources and could find applications in areas as organic electronics, dry food packaging and in the biomedical field. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10570-012-9673-9 Authors Eliane Trovatti, CICECO and Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal Susana C. M. Fernandes, CICECO and Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal Laurent Rubatat, IPREM/EPCP, UMR 5254, Université de Pau et des Pays de l’Adour, Pau, France Carmen S. R. Freire, CICECO and Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal Armando J. D. Silvestre, CICECO and Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal Carlos Pascoal Neto, CICECO and Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    We report a novel cobalt tetraaminophthalocyanine (CoPc) functionalized nanomaterial by spacer-arm immobilization of CoPc onto cellulose nanofiber mats. The spacer-arm was attached through the reaction of tetraethylenepentamine with oxidized cellulose nanofiber mats. CoPc was then covalently immobilized onto the spacer-arm using glutaraldehyde. The functionalization processes on the nanofiber mats were monitored by attenuated total reflection Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. This CoPc functionalized nanomaterial (CoPc-spacer-NM) was used for decoloration of reactive dye wastewater. Incorporation of the spacer-arm resulted in enhanced decoloration with respect to directly immobilized CoPc onto the cellulose nanofiber mats (CoPc-NM). Compared with CoPc-NM, CoPc-spacer-NM shows much higher adsorption capacity when conducted under acidic conditions, which enhances the catalytic oxidation rate of reactive dye when H 2 O 2 was used as an oxidant. Reactive dye wastewater can also be efficiently decolorized by the CoPc-spacer-NM/H 2 O 2 system under basic conditions, despite a relatively weak adsorption capacity. Electron paramagnetic resonance results suggested that the catalytic oxidation process involves the formation and reaction of hydroxyl radicals. Gas chromatography–mass spectrometry showed the main products of the catalytic oxidation of reactive red X-3B were biodegradable aliphatic acids, such as oxalic acid, malonic acid and maleic acid. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10570-012-9701-9 Authors Shi-Liang Chen, MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027 China Xiao-Jun Huang, MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027 China Zhi-Kang Xu, MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027 China Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    The current paper reports on an investigation of the kinetics of chitosan deacetylation by chitin deacetylase isolated from Absidia orchidis vel coerulea . The reaction rate was correlated with the concentration of GlcNHAc units of the polymer. It is shown that the process follows the Michaelis–Menten mechanism. Modification of the Michaelis–Menten equation by introducing the activity of the enzyme instead of its concentration was tested and found to give a better approximation to the experimental data than the original Michaelis–Menten model. Parameters for both the original and the modified Michaelis–Menten equations are also proposed. Content Type Journal Article Pages 363-369 DOI 10.1007/s10570-012-9650-3 Authors Malgorzata M. Jaworska, Faculty of Chemical and Process Engineering, Warsaw University of Technology, ul. Warynskiego 1, 00-645 Warsaw, Poland Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239 Journal Volume Volume 19 Journal Issue Volume 19, Number 2

Description:    In the present study the effect of relative humidity (RH) during spin-coating process on the structural characteristics of cellulose acetate (CA), cellulose acetate phthalate (C-A-P), cellulose acetate butyrate (CAB) and carboxymethyl cellulose acetate butyrate (CMCAB) films was investigated by means of atomic force microscopy (AFM), ellipsometry and contact angle measurements. All polymer solutions were prepared in tetrahydrofuran (THF), which is a good solvent for all cellulose esters, and used for spin-coating at RH of (35 ± 5)%, (55 ± 5)% or (75 ± 5)%. The structural features were correlated with the molecular characteristics of each cellulose ester and with the balance between surface energies of water and THF and interface energy between water and THF. CA, CAB, CMCAB and C-A-P films spin-coated at RH of (55 ± 5)% were exposed to THF vapor during 3, 6, 9, 60 and 720 min. The structural changes on the cellulose esters films due to THF vapor exposition were monitored by means of AFM and ellipsometry. THF vapor enabled the mobility of cellulose esters chains, causing considerable changes in the film morphology. In the case of CA films, which are thermodynamically unstable, dewetting was observed after 6 min exposure to THF vapor. On the other hand, porous structures observed for C-A-P, CAB and CMCAB turned smooth and homogeneous after only 3 min exposure to THF vapor. Content Type Journal Article Pages 443-457 DOI 10.1007/s10570-012-9654-z Authors Leandro S. Blachechen, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, São Paulo, SP 05508-000, Brazil Marcela A. Souza, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, São Paulo, SP 05508-000, Brazil Denise F. S. Petri, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, São Paulo, SP 05508-000, Brazil Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239 Journal Volume Volume 19 Journal Issue Volume 19, Number 2

Description:    Powder and fiber diffraction patterns were calculated for model cellulose crystallites with chains 20 glucose units long. Model sizes ranged from four chains to 169 chains, based on cellulose Iβ coordinates. They were subjected to various combinations of energy minimization and molecular dynamics (MD) in water. Disorder induced by MD and one or two layers of water had small effects on the relative intensities, except that together they reduced the low-angle scattering that was otherwise severe enough to shift the 1 - 1   0 peak. Other shifts in the calculated peaks occurred because the empirical force field used for MD and minimization caused the models to have small discrepancies with the experimental intermolecular distances. Twisting and other disorder induced by minimization or MD increased the breadth of peaks by about 0.2–0.3° 2-θ. Patterns were compared with experimental results. In particular, the calculated fiber patterns revealed a potential for a larger number of experimental diffraction spots to be found for cellulose from some higher plants when crystallites are well-oriented. Either that, or further understanding of those structures is needed. One major use for patterns calculated from models is testing of various proposals for microfibril organization. Content Type Journal Article Pages 319-336 DOI 10.1007/s10570-012-9652-1 Authors Yoshiharu Nishiyama, Centre de Recherche sur les Macromolécules Végétales (CERMAV), Joseph Fourier University of Grenoble, BP 53, 38041 Grenoble Cedex 9, France Glenn P. Johnson, United States Department of Agriculture, Southern Regional Research Center (SRRC), 1100 Robert E. Lee Boulevard, New Orleans, LA 70124, USA Alfred D. French, United States Department of Agriculture, Southern Regional Research Center (SRRC), 1100 Robert E. Lee Boulevard, New Orleans, LA 70124, USA Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239 Journal Volume Volume 19 Journal Issue Volume 19, Number 2

Description:    Four corewood types were examined from sapling trees of two clones of Pinus radiata grown in a glasshouse. Trees were grown either straight to produce normal corewood, tilted at 45° from the vertical to produce opposite corewood and compression corewood, or rocked to produce flexure corewood. Mean cellulose microfibril angle of tracheid walls was estimated by X-ray diffraction and longitudinal swelling measured between an oven dry and moisture saturated state. Lignin and acetyl contents of the woods were measured and the monosaccharide compositions of the cell-wall polysaccharides determined. Finely milled wood was analysed using solution-state 2D NMR spectroscopy of gels from finely milled wood in DMSO- d 6 /pyridine- d 5 . Although there was no significant difference in cellulose microfibril angle among the corewood types, compression corewood had the highest longitudinal swelling. A lignin content 〉32 % and a galactosyl residue content 〉6 % clearly divided severe compression corewood from the other corewood types. Relationships could be drawn between lignin content and longitudinal swelling, and between galactosyl residue content and longitudinal swelling. The 2D NMR spectra showed that the presence of H-units in lignin was exclusive to compression corewood, which also had a higher (1 → 4)-β- d -galactan content, defining a unique composition for that corewood type. Content Type Journal Article Category Original Paper Pages 1-20 DOI 10.1007/s10570-012-9697-1 Authors Maree Brennan, School of Biological Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand J. Paul McLean, School of Biological Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand Clemens M. Altaner, School of Biological Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand John Ralph, Department of Biochemistry, DOE Great Lakes Bioenergy Research Center, Wisconsin Bioenergy Initiative, Madison, WI, USA Philip J. Harris, School of Biological Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Xylans, an important sub-class of hemicelluloses, represent a largely untapped resource for new renewable materials derived from biomass. As with other carbohydrates, nanocellulose reinforcement of xylans is interesting as a route to new bio-materials. With this in mind, birch wood xylan was combined with nanofibrillated cellulose (NFC) and films were cast with and without glycerol, sorbitol or methoxypolyethylene glycol (MPEG) as plasticizers. Microscopy revealed some NFC agglomeration in the composite films as well as a layered nanocellulose structure. Equilibrium moisture content in plasticized films increased with glycerol content but was independent of xylan:NFC ratio in unplasticized films. Sorbitol- and MPEG-plasticized films showed equilibrium moisture contents of approximately 10 wt% independent of plasticizer content. Tensile testing revealed increases in tensile strength with increased NFC content in the xylan:NFC composition range from 50:50 to 80:20 and plasticizer addition generally provided less brittle films. The oxygen permeability of unplasticized xylan-NFC films fell into a range which was similar to that for previously measured pure NFC films and was statistically independent of the xylan:NFC ratio. Water vapor permeability values of 1.9–2.8·10 −11  g Pa −1  m −1  s −1 were found for unplasticized composite films, but these values were significantly reduced in the case of films plasticized with 10–40 wt% sorbitol. Content Type Journal Article Category Original Paper Pages 1-17 DOI 10.1007/s10570-012-9764-7 Authors Natanya M. L. Hansen, Department of Chemical and Biochemical Engineering, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark Thomas O. J. Blomfeldt, Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, 10044 Stockholm, Sweden Mikael S. Hedenqvist, Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, 10044 Stockholm, Sweden David V. Plackett, Department of Chemical and Biochemical Engineering, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    This study demonstrated the potential of simultaneously recovering cellulosic solid residues (CSR) and producing cellulose nanocrystals (CNCs) by strong sulfuric acid hydrolysis to minimize cellulose loss to near zero. A set of slightly milder acid hydrolysis conditions than that considered as “optimal” were used to significantly minimize the degradation of cellulose into soluble sugars that cannot be economically recovered, but resulted in CSR that is easily recoverable through conventional centrifuge. It was found that the window for simultaneous recoveries of CSR and producing high yield CNC in strong acid hydrolysis was extremely narrow. However, we achieved significant CSR yield with near zero cellulose loss but without sacrificing CNC yield compared with that obtained at “optimal condition”. The resultant CSR contains sulfate ester groups that facilitated subsequent mechanical nano-fibrillation to cellulose nanofibrils (CNFs), a potential high value nanocellulosic material for a variety of applications. Content Type Journal Article Category Original Paper Pages 1-15 DOI 10.1007/s10570-012-9765-6 Authors Q. Q. Wang, State Key Lab of Pulp and Paper Engineering, South China University of Technology, Guangzhou, China J. Y. Zhu, USDA Forest Service, Forest Products Laboratory, Madison, WI, USA R. S. Reiner, USDA Forest Service, Forest Products Laboratory, Madison, WI, USA S. P. Verrill, USDA Forest Service, Forest Products Laboratory, Madison, WI, USA U. Baxa, Electron Microscopy Laboratory, SAIC-Frederick, Inc., NCI-Frederick, Frederick, MD 21702, USA S. E. McNeil, Nanotechnology Characterization Laboratory, Advanced Technology Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, MD 21702, USA Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    This study reports the use of solid state ball milling (SSBM) for dispersing cellulose nanowhiskers (CNWs) in starch-based thermoplastics. Prior to conventional drying, interwhiskers agglomeration was minimized by coating the CNWs with pectin, a vegetable hydrocolloid polysaccharide. SSBM and melt-processing were employed to prepare the nanocomposites. A strong correlation between mechanical reinforcement and nanowhisker dispersion was proven by results of tensile tests, scanning electron microscopy and dynamical mechanical thermal analysis. The starch–pectin–CNW nanocomposites showed high dispersion of the nano-sized filler in the matrix, thus SSBM shows great potential when compared to sol–gel, casting/evaporation and other methods to disperse these promising nanoparticles. Content Type Journal Article Category Communication Pages 1-8 DOI 10.1007/s10570-012-9768-3 Authors Francys Kley Vieira Moreira, Laboratório Nacional de Nanotecnologia para o Agronegócio (LNNA), Embrapa Instrumentação (CNPDIA), São Carlos, SP, Brazil José Manoel Marconcini, Laboratório Nacional de Nanotecnologia para o Agronegócio (LNNA), Embrapa Instrumentação (CNPDIA), São Carlos, SP, Brazil Luiz Henrique Capparelli Mattoso, Laboratório Nacional de Nanotecnologia para o Agronegócio (LNNA), Embrapa Instrumentação (CNPDIA), São Carlos, SP, Brazil Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    A mechanism for chemical attachment and growth of a Cu-BTC Metal–Organic Framework, also known as MOF-199 or HKUST-1, onto cellulosic substrates is reported. Four different experimental procedures were attempted in order to elucidate the role of carboxylate groups on the anionic cellulose’s surface. The order of addition of Cu(OAc) 2 —copper acetate, BTH3, 1,3,5-benzenetricarboxylic acid and TEA—Triethylamine was found to be a critical factor for the attachment and growth of the MOF-199 crystals onto anionic cellulose. The presence of MOF-199 crystals was probed using XRD and XPS spectra and a strong chemical interaction to the carboxymethylated cellulose fibers was confirmed by intense and vigorous washing of the specimens with water, DMF and methanol. Based on the recognized ability of MOF-199 to capture gases and toxic chemicals, combined with the availability of cellulose-based fibrous materials, the described procedure provides the basis for future fabrication of functionalized fibers and active filtration media. Content Type Journal Article Category Original Paper Pages 1771-1779 DOI 10.1007/s10570-012-9752-y Authors Marcia da Silva Pinto, Department of Fiber Science and Apparel Design, Cornell University, Ithaca, NY 14853, USA Cesar Augusto Sierra-Avila, Departamento de Química, Universidad Nacional de Colombia, Bogotá, Colombia Juan P. Hinestroza, Department of Fiber Science and Apparel Design, Cornell University, Ithaca, NY 14853, USA Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239 Journal Volume Volume 19 Journal Issue Volume 19, Number 5

Description:    This study demonstrates regioselective oxidation of cellulose nanowhiskers using 2.80–10.02 mmols of sodium periodate per 5 g of whiskers followed by grafting with methyl and butyl amines through a Schiff base reaction to obtain their amine derivatives in 80–90 % yield. We found a corresponding increase in carbonyl content (0.06–0.14 mmols/g) of the dialdehyde cellulose nanowhiskers with the increase in oxidant as measured by titrimetric analysis and this was further evidenced by FT-IR spectroscopy. Grafting of amine compounds to the oxidized cellulose nanowhiskers resulted in their amine derivatives, which are found to be partially soluble in DMSO. Therefore, the reduction reaction between amines and carbonyl groups was confirmed through 13 C NMR spectra, which was also supported by copper titration, XPS, and FT-IR spectroscopy. Morphological integrity and crystallinity of the nanowhiskers was maintained after the chemical modification as studied by AFM and solid-state 13 C NMR, respectively. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10570-012-9769-2 Authors Rajalaxmi Dash, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA Thomas Elder, USDA-Forest Service, Pineville, LA 71360, USA Arthur J. Ragauskas, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    The potential use of cellulose based materials for active food packaging applications was explored. For this purpose, the sorption of lysozyme in a cellulose based paper pulp was optimized using the experimental design methodology. A Face-Centered Composite design was applied to investigate the effect of short/long fibers ratio and carboxymethyl cellulose concentration on linking lysozyme to the fibers surface and to optimize the cellulosic matrix composition. The related polynomial model showed good fitting ability (R 2  〉 0.9) as well as good prediction ability (Q 2  〉 0.8). The best combination of factors was 50 % short fibers, 50 % long fibers and at least 4 % carboxymethyl cellulose. Afterwards the lysozyme release was investigated using a mathematical model based on Fick’s second law. It was able to describe the release kinetics of lysozyme from the paper sheets made with the optimized cellulosic matrix into water at different temperatures (between 4 and 23 °C), pH (from 4 to 7) and NaCl concentrations (from 0.2 to 2 M). The apparent diffusion coefficients for the lysozyme were in the range of 3.1 × 10 −16 –6.6 × 10 −14 and the E a value was 22.1 kJ/mol at pH 5 and NaCl concentration of 0.5 M. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10570-012-9770-9 Authors E. Mascheroni, DEFENS, Department of Food, Environmental and Nutritional Science, University of Milan, Via Celoria 2, 20133 Milan, Italy G. Capretti, INNOVHUB, SSCCP, Italian Pulp and Paper Research Institute, Piazza L. da Vinci 16, 20133 Milan, Italy S. Limbo, DEFENS, Department of Food, Environmental and Nutritional Science, University of Milan, Via Celoria 2, 20133 Milan, Italy L. Piergiovanni, DEFENS, Department of Food, Environmental and Nutritional Science, University of Milan, Via Celoria 2, 20133 Milan, Italy Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    In a persistent search to find affordable biomaterial sources, calcium deficient hydroxyapatite (CdHA) precipitated onto bacterial cellulose (BC) composites are excellent candidates. CdHA is resorbable in vivo and biomimetic to HA found in native bone due to its calcium deficiency. The shape of the starting BC scaffold limits BC/CdHA composite applications. In order to make greater use of these composites, this study aimed to investigate the feasibility in generating a CdHA powder from the original composite. The CdHA powder could be utilized at bone injury sites as stand-alone bone filler or as filler in an injectable system. This study selected thermal and enzymatic methods to investigate the effectiveness of BC removal from the original composite matrix. Scanning electron microscopy was used to examine the nanoscale hydroxyapatite rosettes. Energy dispersive x-ray spectroscopy was used to determine the calcium deficiency of hydroxyapatite. Thermogravimetric analysis was used to detect the presence of cellulose in the composites by mass. Fourier transform infrared spectroscopy was used to obtain chemical information of the degraded materials. Each degradation method successfully produced calcium deficient hydroxyapatite powders. Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10570-012-9767-4 Authors R. L. Hammonds, Materials Science and Engineering, The University of Tennessee, 434 Dougherty Hall, Knoxville, TN 37996, USA M. S. Harrison, Laboratory of Regenerative Medicine, Department of Surgery, University of Tennessee, Knoxville, TN 37920, USA T. C. Cravanas, Laboratory of Regenerative Medicine, Department of Surgery, University of Tennessee, Knoxville, TN 37920, USA W. H. Gazzola, Materials Science and Engineering, The University of Tennessee, 434 Dougherty Hall, Knoxville, TN 37996, USA C. P. Stephens, Laboratory of Regenerative Medicine, Department of Surgery, University of Tennessee, Knoxville, TN 37920, USA R. S. Benson, Materials Science and Engineering, The University of Tennessee, 434 Dougherty Hall, Knoxville, TN 37996, USA Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    In this study we carried out optimization of bacterial cellulose (BC) production from Gluconoacetobacter hansenii NCIM 2529 using a statistical model. Optimization of medium components and physical parameters used for bacterial cellulose production in G. hansenii NCIM 2529 was performed by two-step optimization. Eight culture parameters were screened by the Plackett – Burman design and significant parameters were optimized by the response surface methodology using a central composite design. Through these two-phase experiments, optimization of BC production was carried out for high production. The maximum average productivity of BC with optimized medium was 0.71 g/100 mL upon fermentation in a shake flask. The average BC production was observed to increase by about 44 % using these statistical techniques of media optimization. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10570-012-9760-y Authors Bhavna V. Mohite, School of Life Sciences, North Maharashtra University, P. B. 80, Jalgaon, 425001 Maharashtra, India Kirtee K. Kamalja, Department of Statistics, North Maharashtra University, P. B. 80, Jalgaon, 425001 Maharashtra, India Satish V. Patil, School of Life Sciences, North Maharashtra University, P. B. 80, Jalgaon, 425001 Maharashtra, India Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Freeze-dried nanofibrillated cellulose based-aerogels were produced from cellulosic pulps extracted from Eucalyptus urograndis . Nanofibers were isolated under high pressure and modified with TEMPO-mediated oxidation and/or hydroxyapatite (HAp) to observe potential changes in mechanical properties. Two degrees of oxidation (DO), 0.1 and 0.2, were achieved as measured by conductimetric titration. Oxidized and non-oxidized samples were modified with HAp at a ratio of HAp:cellulose of 0.2:1. Morphology (FE-SEM), pore size, surface area, and mechanical properties were obtained to characterize the produced aerogels. The results clearly demonstrate a homogeneous morphology for aerogels fabricated with oxidized cellulose nanofibers. The nature of water present in the material was measured using time domain-nuclear magnetic resonance spectroscopy (TD-NMR) and demonstrated that it played a key role in the development of the porous and uniform micro-architecture. TEMPO-mediated oxidation and the addition of HAp resulted in aerogels with high mechanical strength as demonstrated from an increase from approximately 75–200 kPa in compressive strength when reduced to 50 % of their original height. However, the contribution of oxidation to the mechanical properties was more pronounced than the addition of HAp. In general, the density of the aerogels varied from 0.008 to 0.011 g/cm 3 in which slightly lightweight aerogels were produced by increasing the degree of oxidation, whereas the incorporation of HAp as a modifying agent for potential bio-based tissue scaffolding matrices did not significantly contribute to higher densities. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10570-012-9761-x Authors Teresa Cristina Fonseca Silva, Departamento de Quimica, Universidade Federal de Viçosa, Viçosa, MG 36570-000, Brazil Youssef Habibi, Laboratory of Soft Materials & Green Chemistry, Department of Forest Biomaterials, North Carolina State University, Raleigh, NC 27695-8005, USA Jorge Luiz Colodette, Departamento de Quimica, Universidade Federal de Viçosa, Viçosa, MG 36570-000, Brazil Thomas Elder, Southern Research Station, Utilization of Southern Forest Resources, USDA Forest Service, 2500 Shreveport Highway, Pineville, LA 71360-2009, USA Lucian A. Lucia, Laboratory of Soft Materials & Green Chemistry, Department of Forest Biomaterials, North Carolina State University, Raleigh, NC 27695-8005, USA Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Contact-active antibacterial surfaces are a novel tool in the antibacterial battle. The preparation of such surfaces usually involves harsh reaction conditions and organic solvents. A more sustainable alternative would involve physical adsorption of water-soluble polyelectrolytes using a renewable substrate. Here, highly charged cationic polyvinylamines (PVAm), with or without hydrophobic modifications, have been adsorbed onto the naturally anionic cellulosic wood-fibres. To increase the amount of PVAm, polyelectrolyte multilayers were prepared using polyacrylic acid as the anionic polyelectrolyte. The modified fibres were characterised for PVAm content, water retention and antibacterial properties. The use of multilayers increased the total polymer content without notably reducing the water swelling. The fibres were shown to have excellent bioactive properties and reduced waterborne Escherichia coli and Bacillus subtilis by more than 99.9 %, which is a generally accepted definition of an antibacterial material. A large reduction in bacterial growth was observed upon addition of nutrients, although minor growth was detected after 24 h. The results further show that one adsorbed polymer layer was sufficient to obtain a contact-active surface, which makes the PVAm multilayer system seemingly unique. No polymer leaching from any of the samples was detected, indicating that the fibres work via a contact-active antibacterial mechanism. The results show the feasibility of constructing a sustainable antibacterial material using a renewable substrate and water-based solutions in the material construction process. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10570-012-9742-0 Authors Josefin Illergård, Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, 100 44 Stockholm, Sweden Ute Römling, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 171 71 Stockholm, Sweden Lars Wågberg, Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, 100 44 Stockholm, Sweden Monica Ek, Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, 100 44 Stockholm, Sweden Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    An in-depth analysis was performed of the molecular deformation mechanisms in cellulose during axial stretching. For the first time, it was demonstrated that entropy affects the stiffness of cellulose nanocrystals significantly. This was achieved through Molecular Dynamics simulations of model nanocrystals subject to constant stress in the axial direction, for nanocrystals of varying lateral dimensions and at different temperatures. The simulations were analyzed in terms of Young’s modulus E , which is a measure of the elastic response to applied stress. A weak but significant temperature dependence was shown, with ∂ E /∂ T  =  −0.05 Gpa K −1 at room temperature, in agreement with experimental numbers. In order to analyze the respective contributions from internal energy and entropy, a decomposition of the total response of the free energy with respect to strain was made. It was shown that the decrease in E with increasing T is due to entropy, and that the magnitude of the decrease is 6–9 % at room temperature compared to the value at 0 K. This was also shown independently by a direct calculation of the vibrational entropy of the cellulose crystal. Finally, it was found that internal hydrogen bonds are contributing to the stiffness by 20 %, mainly by stabilizing the cellulose internal structure. Content Type Journal Article Category Original Paper Pages 1-16 DOI 10.1007/s10570-012-9774-5 Authors Jakob Wohlert, Wallenberg Wood Science Center, KTH Royal Institute of Technology, 10044 Stockholm, Sweden Malin Bergenstråhle-Wohlert, Wallenberg Wood Science Center, KTH Royal Institute of Technology, 10044 Stockholm, Sweden Lars A. Berglund, Wallenberg Wood Science Center, KTH Royal Institute of Technology, 10044 Stockholm, Sweden Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    The aim of this work was to functionalize cotton gauzes with cyclodextrins in order to endow them with the ability to elute antimicrobial agents and to prevent infections. Gauzes were modified according to a two-steps approach: (1) pre-irradiation of the gauzes (Gammabeam) to graft glycidyl methacrylate (GMA), and (2) covalent binding of cyclodextrins (CDs) to the GMA-grafted gauzes. First the dependence of GMA grafting yield on the radiation dose (from 1 to 20 kGy) and the time of reaction was evaluated in detail. Anchorage of β-cyclodextrin (β-CD) and hydroxypropyl-β-cyclodextrin (HP-β-CD) was confirmed by FTIR, TGA, and 3-methylbenzoic acid sorption. Differently from pristine gauzes, CD-functionalized GMA-grafted gauzes were able to load an anionic antibiotic drug, specifically nalidixic acid, and to sustain the release for 6 h. Drug-loaded gauzes were tested in vitro against E. coli and the results prove the suitability of the functionalization approach to efficiently inhibit the growth of this microorganism. Content Type Journal Article Category Original Paper Pages 1-13 DOI 10.1007/s10570-012-9782-5 Authors Erick Hiriart-Ramírez, Departamento de Química de Radiaciones y Radioquímica, Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, 04510 Mexico, DF, Mexico Angel Contreras-García, Department of Engineering Physics, École Polytechnique, C.P. 6079, Succ. Centre-Ville, Montreal, QC H3C 3A7, Canada Maria José Garcia-Fernandez, Departamento de Farmacia y Tecnología Farmacéutica, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain Angel Concheiro, Departamento de Farmacia y Tecnología Farmacéutica, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain Carmen Alvarez-Lorenzo, Departamento de Farmacia y Tecnología Farmacéutica, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain Emilio Bucio, Departamento de Química de Radiaciones y Radioquímica, Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, 04510 Mexico, DF, Mexico Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    The contents of cellulose, total carbohydrates, sugars (fructose, glucose, galactose, sucrose, and cellobiose), and minerals (nitrogen, phosphorus, potassium, sulfur, calcium, and magnesium) were determined at various stages of fiber development in the brown cotton cultivar ZX-1, the green cotton cultivar G-7, and the white cotton cultivar LMY28 of Gossypium hirsutum L. Cellulose contents during fiber development changed along S-shaped curves among the tested cotton cultivars. The cellulose content was significantly higher in the white cotton cultivar LMY28 than in the colored cotton cultivars ZX-1 and G-7 after 25 days post anthesis (DPA). Sugar and mineral contents showed significant changes during fiber development. Fructose, glucose, galactose, cellobiose, nitrogen, phosphorus, potassium, sulfur, and magnesium contents were essential for cellulose deposition during fiber development. In this study, glucose was shown to be a direct precursor and key sugar in cellulose biosynthesis in cotton cultivars. There may be a special mechanism in colored cotton cultivars that greater amounts of total carbohydrates, especially glucose, and minerals (nitrogen, phosphorus, potassium, sulfur, and magnesium) were consumed by the biosynthesis and deposition of fiber pigments than in the biosynthesis of cellulose. This finding could explain why the cellulose content was significantly lower in the colored cotton cultivars than in white cotton. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10570-012-9776-3 Authors Meiling Zhang, State Key Laboratory of Crop Biology, Agronomy College, Shandong Agricultural University, Tai’an, 271018 Shandong, China Xianliang Song, State Key Laboratory of Crop Biology, Agronomy College, Shandong Agricultural University, Tai’an, 271018 Shandong, China Xuezhen Sun, State Key Laboratory of Crop Biology, Agronomy College, Shandong Agricultural University, Tai’an, 271018 Shandong, China Zhenlin Wang, State Key Laboratory of Crop Biology, Agronomy College, Shandong Agricultural University, Tai’an, 271018 Shandong, China Zongtai Li, State Key Laboratory of Crop Biology, Agronomy College, Shandong Agricultural University, Tai’an, 271018 Shandong, China Hong Ji, State Key Laboratory of Crop Biology, Agronomy College, Shandong Agricultural University, Tai’an, 271018 Shandong, China Xiaolong Xu, State Key Laboratory of Crop Biology, Agronomy College, Shandong Agricultural University, Tai’an, 271018 Shandong, China Jinpu Li, State Key Laboratory of Crop Biology, Agronomy College, Shandong Agricultural University, Tai’an, 271018 Shandong, China Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    A conductive paper was made of cellulose fibers with a multilayer of polyethyleneimine (PEI) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and the factors to increase the conductivity of the paper were investigated. The adsorption amount and the structure of PEI and PEDOT:PSS multilayer was changed by controlling salt concentration and the number of layers, and inter-contact degree of fibers was controlled by calendering. The adsorption behavior of the polyelectrolytes onto cellulose was evaluated using a quartz crystal microbalance with dissipation monitoring, and the adsorption amount was quantitatively analyzed through Kjeldahl nitrogen analysis and an Inductively Coupled Plasma Optical Emission Spectrometer. The conductivity of the resultant paper was in the range of 10 −5 –10 −4  S/cm without loss of paper strength. The conductivity of the paper increased when the multilayer was formed at low salt concentration and the conductive paper was calendered. It appeared that electron transfer by increased contact between PEDOT:PSS improved the conductivity of the paper. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10570-012-9781-6 Authors Jegon Lee, Department of Forest Sciences, College of Agriculture and Life Sciences, Seoul National University, 1, Gwanak-ro, Gwanak-gu, Seoul, 151-921 Korea Jaeho Ryu, Department of Forest Sciences, College of Agriculture and Life Sciences, Seoul National University, 1, Gwanak-ro, Gwanak-gu, Seoul, 151-921 Korea Hye Jung Youn, Department of Forest Sciences, College of Agriculture and Life Sciences, Seoul National University, 1, Gwanak-ro, Gwanak-gu, Seoul, 151-921 Korea Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Cellulose viscose fibres were functionalized by novel amino cellulose sulfates (ACS), namely 6-deoxy-6-(ω-aminoethyl) amino cellulose-2,3(6)-O-sulfate (AECS), and 6-deoxy-6-(2-(bis- N ′, N ′-(2-aminoethyl)aminoethyl)) amino cellulose-2,3(6)-O-sulfate (BAECS). In this way an amphoteric characteristics were introduced onto cellulose viscose fibers which is extremely important by fiber applications. Whilst cellulose fibers possess only negligible carboxyl groups’ content, the coating of fibers by AECS and BAECS, respectively, introduces new functional groups to the fibers; as positively-charged amino groups and negatively-charged sulfate groups. The typical functional groups within the non-coated fibers, as well in the ACS-coated fibers, were characterized by means of X-ray photoelectron spectroscopy, conductometric-, potentiometric and polyelectrolyte titrations, as well as conventionally by the spectroscopic methylene-blue method. The electro-kinetic behavior was evaluated by measuring the zeta-potential of the fibers as a function of pH. The amounts of the positive-charges (introduced protonated amino groups) determined by potentiometric titration agreed with the amounts of the positive charges determined by conductometric titration. The total amounts of negatively-charged fiber groups (sulfate and carboxyl) determined by polyelectrolyte titration were 38.8 and 32.1 mMol kg −1 for AECS-Vis and BAECS-Vis, respectively, and these results were in accordance with the conventional methylene-blue method. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10570-012-9778-1 Authors Taha Genco, Friedrich Schiller University of Jena, Institute for Organic Chemistry and Macromolecular Chemistry, Center of Excellence for Polysaccharide Research, Humboldtstraße 10, 07743 Jena, Germany Lidija Fras Zemljič, Laboratory for Characterization and Processing of Polymers, Faculty of Mechanical Engineering, University of Maribor, Smetanova 17, 2000 Maribor, Slovenia Matej Bračič, Laboratory for Characterization and Processing of Polymers, Faculty of Mechanical Engineering, University of Maribor, Smetanova 17, 2000 Maribor, Slovenia Karin Stana-Kleinschek, Laboratory for Characterization and Processing of Polymers, Faculty of Mechanical Engineering, University of Maribor, Smetanova 17, 2000 Maribor, Slovenia Thomas Heinze, Friedrich Schiller University of Jena, Institute for Organic Chemistry and Macromolecular Chemistry, Center of Excellence for Polysaccharide Research, Humboldtstraße 10, 07743 Jena, Germany Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Fourier-transform infrared spectroscopy and non-isothermal methods—chemiluminometry, differential scanning calorimetry, and differential thermogravimetry—were used to characterize potential structural changes of thiol-modified hyaluronans. Degradative conditions tested via rotational viscometry were first initiated applying oxidative Weissberger ’s system in a reaction system under aerobic conditions. Several low-molecular-weight thiol compounds—cysteamine, l -cysteine, and N -acetyl- l -cysteine—were subsequently tested for their potential antioxidative effects against hyaluronan degradation. It was shown that different final values of dynamic viscosity of hyaluronan solutions were dependent on the thiol structure and its initial concentration. An idea has been put forward that together with the reduction of the hyaluronan molecular weight, which is a consequence of fragmentation, the degradation products might contain associated or even cross-linked structures. In the case of N -acetyl- l -cysteine application, the carbonaceous residue evidenced by differential thermogravimetry was increased when compared to that of intact hyaluronan. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10570-012-9775-4 Authors Eva Hrabárová, Department of Carbohydrate Enzymology, Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 84538 Bratislava, Slovak Republic Jozef Rychlý, Polymer Institute, Slovak Academy of Sciences, 84541 Bratislava, Slovak Republic Vlasta Sasinková, Department of Analytical Chemistry, Institute of Chemistry, Slovak Academy of Sciences, 84538 Bratislava, Slovak Republic Katarína Valachová, Institute of Experimental Pharmacology and Toxicology, Slovak Academy of Sciences, 84104 Bratislava, Slovak Republic Ivica Janigová, Polymer Institute, Slovak Academy of Sciences, 84541 Bratislava, Slovak Republic Katarína Csomorová, Polymer Institute, Slovak Academy of Sciences, 84541 Bratislava, Slovak Republic Ivo Juránek, Institute of Experimental Pharmacology and Toxicology, Slovak Academy of Sciences, 84104 Bratislava, Slovak Republic Ladislav Šoltés, Institute of Experimental Pharmacology and Toxicology, Slovak Academy of Sciences, 84104 Bratislava, Slovak Republic Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    2,3-Di- O -myristyl-6- O -(zinc(II) phthalocyaninyl) cellulose ( 5 ) was synthesized from cellulose ( 1 ) by five reaction steps via 6- O -(3′,4′-dicyanophenyl)-2,3-di- O -myristyl cellulose ( 4 ). The key reaction was phthalocyanine-ring formation on a cellulose backbone, that is, the reaction of compound 4 with o -phthalodinitrile in the presence of hexamethyldisilazane and zinc acetate in DMF afforded to compound 5 in 35.4 % yield. Consequently, the degree of substitution with phthalocyanine moieties of compound 5 was 0.38. The LB monolayer film of compound 5 on an indium tin oxide (ITO) electrode was found to show photocurrent generation performance at 680 nm. Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10570-012-9772-7 Authors Yasuko Saito, Division of Forest and Biomaterials Science, Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan Toshiyuki Takano, Division of Forest and Biomaterials Science, Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan Keita Sakakibara, Division of Forest and Biomaterials Science, Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan Hiroshi Kamitakahara, Division of Forest and Biomaterials Science, Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan Fumiaki Nakatsubo, Division of Forest and Biomaterials Science, Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Enterobacter sp. CJF-002, which had been isolated as a cellulose producer with saccharides as a carbon source, was shown to efficiently produce cellulose from beet molasses (B-Mol) and biodiesel fuel by-product (BDF-B), renewable non-edible and inexpensive biomasses. The cellulose production rates of Enterobacter sp. CJF-002 using B-Mol and BDF-B as carbon sources were faster than those of Acetobacter xylinum ( A. xylinum ) ATCC23769, a representative cellulose producing bacterium. To clarify the biosynthetic machinery of cellulose in the strain, genes responsible for cellulose biosynthesis were cloned. Six open reading frames (ORFs) were suggested to be clustered and their amino acid sequences had high similarities with those of BcsA, BcsB, BcsZ (endoglucanase), BcsC, YhjQ, and YhjK from Escherichia coli , respectively. Of these, the former four genes showed low similarities to corresponding orthologs in a cellulose biosynthetic gene cluster of A. xylinum . A bcsC -knockout mutant produced no cellulose, confirming that the gene is essential for cellulose production of Enterobacter sp. CJF-002. The predicted three-dimensional structure of BcsZ En from Enterobacter sp. CJF-002 had high similarity with that of CMCax (endoglucanase) from A. xylinum ATCC23769 in spite of the low similarity in their amino acid sequences. Taken together, A. xylinum and Enterobacter sp. CJF-002 might produce cellulose via a similar synthetic mechanism. Content Type Journal Article Category Original Paper Pages 1-13 DOI 10.1007/s10570-012-9777-2 Authors Naoki Sunagawa, Graduate School of Chemical Sciences and Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo, 060-8628 Japan Kenji Tajima, Faculty of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo, 060-8628 Japan Mariko Hosoda, Faculty of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo, 060-8628 Japan Shin Kawano, Database Center for Life Science, Research Organization of Information and Systems, 2-11-16 Yayoi, Bunkyo-ku, Tokyo, 113-0032 Japan Ryota Kose, Faculty of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo, 060-8628 Japan Yasuharu Satoh, Faculty of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo, 060-8628 Japan Min Yao, Faculty of Advanced Life Science, Hokkaido University, N10W8, Kita-ku, Sapporo, 060-0810 Japan Tohru Dairi, Faculty of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo, 060-8628 Japan Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Water-soluble cyanoethyl cellulose (CEC) samples were synthesized by homogeneous reaction of cellulose with acrylonitrile in LiOH/urea aqueous solutions. The dynamic viscoelastic property of CEC with different degree of substitution (DS) in water at different temperatures and concentrations were investigated. At low concentrations, the CEC solutions displayed liquid-like behavior with G ′ smaller than G ′′ at low frequencies; while the curves of G ′ and G ′′ intersected at the middle of the frequency range at higher concentration, indicating an existence of chain aggregation and entanglement network. The gelation temperature ( T gel ) was determined from the point of intersection in tan δ versus temperature ( T ) at different frequencies, indicating the validity of Winter–Chambon criteria. It was found that T gel increased with increasing DS, and that the exponent ( n ) values at the gel point decreased with increasing DS. The heating–cooling process proved that the sol–gel transition for CECs in water was thermally irreversible. The AFM images revealed that the particles packed loosely together to form gel aggregates. Moreover, the Maxwell model with four elements was used to describe the frequency dependencies of G ′ and G ′′ for CEC in aqueous solution. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10570-012-9739-8 Authors Qian Li, Department of Chemistry, Wuhan University, Wuhan, 430072 China Jinping Zhou, Department of Chemistry, Wuhan University, Wuhan, 430072 China Lina Zhang, Department of Chemistry, Wuhan University, Wuhan, 430072 China Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    The moisture sorption behavior of developing cotton fibers is studied by dynamic vapor sorption. Mature fibers show a typical sigmoidal isotherm, IUPAC type II, describing the adsorption on macroporous and non-porous adsorbents with a typical hysteresis. This is different from the type III isotherms exhibited by elongating fibers explained by the weak adsorbate–adsorbent interactions. The maximum sorption capacity clearly decreases throughout the cotton fiber development. This decrease is very rapid during the elongation phase of the fibers, but declines beyond 25 days post anthesis (DPA). This transition corresponds to the time point where the secondary cell wall becomes dominant over the primary cell wall, as confirmed with FT-IR. Also only little moisture hysteresis appeared during the elongation phase whereas from 25 DPA onwards a distinct hysteresis is observed that remains almost constant until maturation of the fiber. The study clearly elucidates the sorption mechanism during the elongation phase of the fiber to be different from the one during the secondary cell wall synthesis. This improved understanding of the cotton sorption behavior is important for optimal application of cotton fiber in novel materials. Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10570-012-9737-x Authors Özgür Ceylan, Department of Textiles, Ghent University, Technologiepark 907, 9052 Zwijnaarde, Ghent, Belgium Lieve Van Landuyt, Department of Textiles, Ghent University, Technologiepark 907, 9052 Zwijnaarde, Ghent, Belgium Frank Meulewaeter, Bayer CropScience NV, Technologiepark 38, 9052 Ghent, Belgium Karen De Clerck, Department of Textiles, Ghent University, Technologiepark 907, 9052 Zwijnaarde, Ghent, Belgium Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Bamboo cellulose nanocrystals (CNCs) were successfully prepared from the sulfuric acid hydrolysis of bamboo bleached fibers. Reaction parameters such as temperature, acid-to-pulp ratio and hydrolysis time were varied over a limited range and conditions for the preparation of individual bamboo nanorods with a yield of 30 % were identified. The characteristics of bamboo CNCs were compared with those of CNCs obtained from three other sources, namely eucalyptus, sisal and curauá, prepared using already reported conditions. The shape and size of all four types of CNCs were investigated by complementary techniques, namely transmission electron microscopy, atomic force microscopy, dynamic light scattering and X-ray diffraction. The surface charge of the nanocrystals was determined by conductometric titration and zeta potential measurements. In all cases, negatively charged ribbon-like nanoparticles constituted of a few laterally associated elementary crystallites were observed. The influence of the reaction parameters on the CNC characteristics was discussed and compared with the data reported in the literature. Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10570-012-9738-9 Authors Bernardo S. L. Brito, Departamento de Química, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG CEP 31270-90, Brazil Fabiano V. Pereira, Departamento de Química, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG CEP 31270-90, Brazil Jean-Luc Putaux, Centre de Recherches sur les Macromolécules Végétales (CERMAV-CNRS), BP 53, 38041 Grenoble Cedex 9, France Bruno Jean, Centre de Recherches sur les Macromolécules Végétales (CERMAV-CNRS), BP 53, 38041 Grenoble Cedex 9, France Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Since cellulose accessibility has become more recognized as the major substrate characteristic limiting hydrolysis rates and glucan digestibilities, cellulose solvent-based lignocellulose pretreatments have gained attention. In this study, we employed cellulose solvent- and organic solvent-based lignocellulose fractionation using two cellulose solvents: concentrated phosphoric acid [~85 % (w/w) H 3 PO 4 ] and an ionic liquid Butyl-3-methylimidazolium chloride ([BMIM]Cl). Enzymatic glucan digestibilities of concentrated phosphoric acid- and [BMIM]Cl-pretreated corn stover were 96 and 55 % after 72 h at five filter paper units of cellulase per gram of glucan, respectively. Regenerated amorphous cellulose by concentrated phosphoric acid and [BMIM]Cl had digestibilities of 100 and 92 %, respectively. Our results suggested that differences in enzymatic glucan digestibilities of concentrated phosphoric acid- and [BMIM]Cl-pretreated corn stover were attributed to combinatory factors. These results provide insights into mechanisms of cellulose solvent-based pretreatment and effects of residual cellulose solvents and lignin on enzymatic cellulose hydrolysis. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10570-012-9719-z Authors Noppadon Sathitsuksanoh, Biological Systems Engineering Department, Virginia Tech, 210-A Seitz Hall, Blacksburg, VA 24061, USA Zhiguang Zhu, Biological Systems Engineering Department, Virginia Tech, 210-A Seitz Hall, Blacksburg, VA 24061, USA Y.-H. Percival Zhang, Biological Systems Engineering Department, Virginia Tech, 210-A Seitz Hall, Blacksburg, VA 24061, USA Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Different approaches towards hydrophobic modification of bacterial cellulose aerogels with the alkyl ketene dimer (AKD) reagent are presented. If AKD modification was performed in supercritical CO 2 , an unexpectedly high degree of loading was observed. About 15 % of the AKD was bound covalently to the cellulose matrix, while the other part consisted of re-extractable AKD-carbonate oligomers, which are novel chemical structures described for the first time. These oligomers contain up to six AKD and CO 2 moieties linked by enolcarbonate structures. The humidity uptake from environments with different relative humidity by samples equipped with up to 30 % AKD is strongly reduced, as expected due to the hydrophobization effect. Samples above 30 % AKD, and especially at very high loading between 100 and 250 %, showed the peculiar effect of increased humidity uptake which even exceeded the value of unmodified bacterial cellulose aerogels. Content Type Journal Article Category Original Paper Pages 1-13 DOI 10.1007/s10570-012-9728-y Authors Axel Russler, Christian Doppler Laboratory for Advanced Cellulose Chemistry and Analytics, University of Natural Resources and Life Sciences Vienna, Muthgasse 18, 1190 Vienna, Austria Marcel Wieland, Christian Doppler Laboratory for Advanced Cellulose Chemistry and Analytics, University of Natural Resources and Life Sciences Vienna, Muthgasse 18, 1190 Vienna, Austria Markus Bacher, Christian Doppler Laboratory for Advanced Cellulose Chemistry and Analytics, University of Natural Resources and Life Sciences Vienna, Muthgasse 18, 1190 Vienna, Austria Ute Henniges, Christian Doppler Laboratory for Advanced Cellulose Chemistry and Analytics, University of Natural Resources and Life Sciences Vienna, Muthgasse 18, 1190 Vienna, Austria Peter Miethe, FZMB GmbH Forschungszentrum für Medizintechnik und Biotechnologie, Bad Langensalza, Germany Falk Liebner, Christian Doppler Laboratory for Advanced Cellulose Chemistry and Analytics, University of Natural Resources and Life Sciences Vienna, Muthgasse 18, 1190 Vienna, Austria Antje Potthast, Christian Doppler Laboratory for Advanced Cellulose Chemistry and Analytics, University of Natural Resources and Life Sciences Vienna, Muthgasse 18, 1190 Vienna, Austria Thomas Rosenau, Christian Doppler Laboratory for Advanced Cellulose Chemistry and Analytics, University of Natural Resources and Life Sciences Vienna, Muthgasse 18, 1190 Vienna, Austria Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Amino cellulose sulfate (ACS); namely 6-deoxy-6-(ω-aminoethyl) amino cellulose-2,3(6)- O -sulfate (AECS) and 6-deoxy-6-(2-(bis- N ′, N ′-(2-aminoethyl)aminoethyl)) amino cellulose-2,3(6)- O -sulfate (BAECS) were prepared by a three step synthesis starting with the functionalization of microcrystalline cellulose with p -toluenesulfonyl (tosyl) groups (degree of substitution, DS Tos between 0.55 and 1.37). Subsequently the introduction of the sulfate moieties was carried out (DS Sulf between 1.09 and 1.27) and the tosyl groups at position 6 were replaced by a nucleophilic substitution reaction. As nucleophilic agents 1,2-diaminoethane and tris-(2-aminoethyl)amine were applied, yielding AECS (DS AEA values between 0.41 and 0.86) and BAECS (DS BAEA values between 0.32 and 0.74), respectively. The ACS samples were characterized by means of elemental analysis, 13 C-NMR-, FT-IR-, and UV–Vis spectroscopy. Moreover, the solubility of the samples in water at different pH values and the molecular weights of the samples in aqueous solution were studied. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10570-012-9725-1 Authors Thomas Heinze, Institute of Organic Chemistry and Macromolecular Chemistry, Center of Excellence for Polysaccharide Research, Friedrich Schiller University of Jena, Humboldtstraße 10, 07743 Jena, Germany Taha Genco, Institute of Organic Chemistry and Macromolecular Chemistry, Center of Excellence for Polysaccharide Research, Friedrich Schiller University of Jena, Humboldtstraße 10, 07743 Jena, Germany Katrin Petzold-Welcke, Institute of Organic Chemistry and Macromolecular Chemistry, Center of Excellence for Polysaccharide Research, Friedrich Schiller University of Jena, Humboldtstraße 10, 07743 Jena, Germany Holger Wondraczek, Institute of Organic Chemistry and Macromolecular Chemistry, Center of Excellence for Polysaccharide Research, Friedrich Schiller University of Jena, Humboldtstraße 10, 07743 Jena, Germany Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    The reactivity of dissolving pulps towards derivatization or dissolution is a crucial quality parameter and is mainly determined by the accessibility of the hydroxyl groups. When dissolving pulps are produced from paper-grade pulps by cold caustic extraction (CCE), their reactivity is often inferior as compared to commercial prehydrolysis kraft dissolving pulps. It was hypothesized that pulp reactivity can be enhanced by the introduction of small amounts of substituents to facilitate interchain accessibility. In this study, CCE-treated Eucalyptus globulus kraft paper pulp was subjected to TEMPO-mediated oxidation to initiate partial oxidation of the C 6 -hydroxyl groups to carboxyl groups. The effect of this pulp modification on the reactivity towards xanthation and the subsequent dissolution in diluted aqueous alkali solution (viscose process) as well as the dissolution in complexing and non-complexing solvents, respectively, was thoroughly examined. The results revealed that the oxidized pulps rich in C 6 -carboxylate groups impeded the xanthation reaction obviously because of the reduced availability of hydroxyl groups. When N -methylmorpholine- N -oxide monohydrate was used as a direct solvent, a very high content of C 6 -carboxylate groups was found to reduce the solubility of the pulp fibers as less hydrogen bonds can be formed with NMMO·H 2 O. In the case of dissolution in the complexing solvent cupriethylenediamine, the dissolution mechanism of cellulose was not deteriorated by the high content of C 6 -carboxylate groups. Instead, the oxidation procedure increased the hydrophilic character and the swelling capacity of the outer cell wall layers allowed homogeneous dissolution. Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10570-012-9729-x Authors Verena Gehmayr, Kompetenzzentrum Holz GmbH, Altenbergerstraße 69, 4040 Linz, Austria Antje Potthast, Department of Chemistry, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria Herbert Sixta, Department of Forest Products Technology, Aalto University, 00076 Aalto, Finland Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    The degradation of cellulose in paper due to the formation of a tideline at the wet-dry interface when paper is suspended in water was explored. SEC/MALS was used to assess the molar mass, while ICP/MS, SEM/EDS and CE/UV provided a qualitative and quantitative analysis of the elements and inorganic ions present in the paper. Immediately after the formation of the tideline, no significant depolymerization was observed at the wet-dry interface, despite the accumulation of water soluble brown and/or fluorescent degradation compounds and salts containing sodium, chlorine, sulfur and calcium. Various artificial aging configurations were applied to the paper with tidelines to evaluate the effect of the material accumulated at the wet-dry interface on the long-term stability of paper. The decrease in the molar mass of cellulose (above, at and below the tideline) differed depending on the type of aging, i.e. whether the entire sheet of paper was aged or whether small amounts of paper from the different areas were sampled and aged, individually or together, which evidences a complex degradation pathway. In the former aging configuration the material accumulated in the tideline affected the degradation of the tideline area to the same extent or more than the other areas. When the different areas of the paper sheet were sampled and aged together, it was found that the presence of the tideline clearly affected the degradation of the other paper areas. Conversely, in that case, cellulose within the tidelines was the least degraded. The area below the tideline, through which the water migrated, showed the most significant degradation. Content Type Journal Article Category Original Paper Pages 1-13 DOI 10.1007/s10570-012-9722-4 Authors Myung-Joon Jeong, Centre de Recherche sur la Conservation des Collections, Muséum National d’Histoire Naturelle, CNRS-USR 3224, 36 rue Geoffroy-Saint-Hilaire, 7005 Paris, France Anne-Laurence Dupont, Centre de Recherche sur la Conservation des Collections, Muséum National d’Histoire Naturelle, CNRS-USR 3224, 36 rue Geoffroy-Saint-Hilaire, 7005 Paris, France E. René de la Rie, National Gallery of Art, 401 Constitution Avenue NW, Washington, DC 20565, USA Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Microcrystalline cellulose (MCC) and spherical nanocrystalline cellulose (SNCC) were successfully prepared from waste cotton fabrics through acid hydrolysis. The comparative analysis of the morphology and structure between the obtained MCC and SNCC was carried out. The SNCC suspension exhibited higher stability than the MCC suspension. Transmission electron microscopy in combination with atomic force microscopy showed that the cellulose nanospheres with average size of 35 nm were achieved, while the average particle size of MCC was 49 μm. The MCC and SNCC had similar functional groups and crystalline structure as confirmed by Fourier transform infrared spectroscopy and X-ray diffraction analysis, respectively. Viscometric average molecular weight measurement and thermo gravimetric analysis indicated that the degree of polymerization and thermal stability of SNCC was lower than that of MCC. These results should improve understanding of the characteristics of MCC and SNCC derived from waste cotton fabrics and lead to many new applications. Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10570-012-9730-4 Authors Rui Xiong, State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu, 610065 China Xinxing Zhang, State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu, 610065 China Dong Tian, State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu, 610065 China Zehang Zhou, State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu, 610065 China Canhui Lu, State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu, 610065 China Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    The temporal and spatial evolution of concentration profiles of bovine serum albumin (BSA) in various cellulosic fiber beds is measured using magnetic resonance imaging. Effective diffusivities are calculated using a numerical one dimensional Fickian model to match experimental concentration profiles. Experimental values of the diffusivities are compared with predictions from a simple diffusion-adsorption model which accounts for porosity, tortuosity, and surface adsorption. BSA was found to have negligible adsorption in the concentration range studied, resulting in a simplified diffusion model based on fiber characteristics and geometry. Effective diffusivities agreed well with the predicted values and were within an order of magnitude of the estimated bulk diffusivity of BSA. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10570-012-9732-2 Authors David M. Lavenson, Department of Chemical & Materials Science Engineering, University of California Davis, Davis, CA 95616, USA Emilio J. Tozzi, Department of Chemical & Materials Science Engineering, University of California Davis, Davis, CA 95616, USA Michael J. McCarthy, Department of Food Science & Technology, University of California Davis, Davis, CA 95616, USA Robert L. Powell, Department of Chemical & Materials Science Engineering, University of California Davis, Davis, CA 95616, USA Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Cellulose/silver nanoparticles (Ag NPs) composites were prepared and their catalytic performance was evaluated. Porous cellulose microspheres, fabricated from NaOH/thiourea aqueous solution by a sol–gel transition processing, were served as supports for Ag NPs synthesis by an eco-friendly hydrothermal method. The regenerated cellulose microspheres were designed as reducing reagent for hydrothermal reduction and also micro-reactors for controlling growth of Ag NPs. The structure and properties of obtained composite microspheres were characterized by Optical microscopy, UV–visible spectroscopy, WXRD, SEM, TEM and TG. The results indicated that Ag NPs were integrated successfully and dispersed uniformly in the cellulose matrix. Their size (8.3–18.6 nm), size distribution (3.4–7.7 nm), and content (1.1–4.9 wt%) were tunable by tailoring of the initial concentration of AgNO 3 . Moreover, the shape, integrity and thermal stability were firmly preserved for the obtained composite microspheres. The catalytic performance of the as-prepared cellulose/Ag composite microspheres was examined through a model reaction of 4-nitrophenol reduction in the presence of NaBH 4 . The composites microspheres exhibited good catalytic activity, which is much high than that of hydrogel/Ag NPs composites and comparable with polymer core–shell particles loading Ag NPs. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10570-012-9731-3 Authors Junjie Wu, Beijing National Laboratory for Molecular Sciences, Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190 People’s Republic of China Ning Zhao, Beijing National Laboratory for Molecular Sciences, Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190 People’s Republic of China Xiaoli Zhang, Beijing National Laboratory for Molecular Sciences, Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190 People’s Republic of China Jian Xu, Beijing National Laboratory for Molecular Sciences, Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190 People’s Republic of China Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    A 3-D phase diagram of the HPC/H 2 O/H 3 PO 4 tertiary system against various temperatures was established. Four distinct phases—the completely separated phase (S), the cloudy suspension phase (CS), the liquid crystalline miscible phase (LC), and the isotropically miscible phase (I)—were identified. The S phase shrank as the temperature increased, revealing that the HPC solubility increased with temperature, regardless of the LCST (lower critical solution temperature) characteristic. The addition of H 3 PO 4 suppressed the formation of LC phase. However, as the temperature was raised sharply from 50 to 70 °C, the LC phase could only be maintained at high H 3 PO 4 concentration region; it was a triangular shape, and the top apex of the triangle was the temperature-invariant L* point (HPC/H 2 O/H 3 PO 4 38/9/53 wt%). The CS phase expanded considerably into the H 2 O-rich but H 3 PO 4 -poor region when the temperature continued to increase over 48 °C. The LCST points of the CS phase that contained 0 and 15 wt% of H 3 PO 4 were 34 and 38 °C, respectively. These CS results demonstrate that H 3 PO 4 suppresses the occurrence of LCST behavior. Additionally, the binodal curve exhibits a weak or even zero dependence of binodal temperature on the HPC concentration at HPC concentrations of less than 30 wt% in a pure water system. A hypothesis concerning the sequential desorption of water molecules was proposed to explain such behavior. Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10570-012-9707-3 Authors Syang-Peng Rwei, Institute of Organic and Polymeric Materials, National Taipei University of Technology, #1, Sec 3, Chung-Hsiao E. Rd., Taipei, Taiwan, ROC Mei-Sia Lyu, Institute of Organic and Polymeric Materials, National Taipei University of Technology, #1, Sec 3, Chung-Hsiao E. Rd., Taipei, Taiwan, ROC Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    This research aims to develop new materials based on renewable resources that can fulfill the functions necessary in the absorption core of a disposable diaper. Absorbent foam was recently produced from softwood kraft pulp by TEMPO oxidation, disintegration and freeze drying. In this study, the TEMPO-oxidized MFC was mixed with pulp fibres, thus forming a cellulosic composite, in an attempt to improve the mechanical stability of the freeze-dried absorbent material. The fibres were added in different amounts and the freeze-dried materials were evaluated for their absorption and retention properties. The results of this study suggest that the composite material has a better mechanical stability than the absorbent foam without fibres. It was shown that using spruce CTMP fibres in the composite resulted in better absorption and retention capacities than in a composite with softwood kraft pulp fibres. The higher stiffness of the CTMP fibres is a probable explanation for this difference. For the composite material with CTMP fibres, liquid porosimetry showed that pore size distribution was more or less retained when put under load. Furthermore, it was seen that the retention properties reached a maximum around 85 % CTMP fibres and 15 % TEMPO-oxidized MFC. In the centrifuge retention test, the retention of the TEMPO-oxidized MFC in the composite material reached about the same capacity as conventional superabsorbent polymers. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10570-012-9706-4 Authors Fredrik Wernersson Brodin, Forest Products and Chemical Engineering, Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden Kristoffer Lund, Forest Products and Chemical Engineering, Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden Harald Brelid, Forest Products and Chemical Engineering, Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden Hans Theliander, Forest Products and Chemical Engineering, Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Photoactive derivatives of cellulose were prepared by a mild esterification of the biopolymer with 2-[(4-methyl-2-oxo-2H-chromen-7-yl)oxy]acetic acid via the activation of the carboxylic acid with N,N′ -carbonyldiimidazole. Subsequently, modification with the cationic carboxylic acid (3-carboxypropyl)trimethylammonium chloride was carried out. Thus, water soluble polyelectrolytes decorated with high amounts of photochemically active chromene moieties were obtained. The structures of the novel polysaccharide esters and the polyelectrolytes were evaluated by means of NMR and IR spectroscopy. Moreover, the light triggered photodimerization of the chromene moieties of the photoactive polyelectrolytes was studied by means of UV–Vis spectroscopy in the dissolved state. The photochemistry observed may be used to control the properties of the new polysaccharide derivatives and are thus of interest in the design of smart materials. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10570-012-9708-2 Authors Holger Wondraczek, Center of Excellence for Polysaccharide Research, Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University of Jena, Humboldtstraße 10, 07743 Jena, Germany Annett Pfeifer, Center of Excellence for Polysaccharide Research, Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University of Jena, Humboldtstraße 10, 07743 Jena, Germany Thomas Heinze, Center of Excellence for Polysaccharide Research, Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University of Jena, Humboldtstraße 10, 07743 Jena, Germany Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    A novel synthetic method to link acetylated cellulose derivatives with methylated cellulose derivatives via Huisgen 1,3-dipolar cycloaddition was developed to produce 1,2,3-triazole-linked diblock copolymers consisting of hydrophilic cellobiose or low-molecular-weight cellulose and a hydrophobic 2,3,6-tri- O -methyl-cellulose. Huisgen 1,3-dipolar cycloaddition had the advantage over glycosylation reaction of being able to connect a hydrophilic block having higher molecular weight than cellobiose with a hydrophobic 2,3,6-tri- O -methyl-cellulose block. As a consequence, 2.0 wt% aqueous solutions of the 1,2,3-triazole-linked diblock methylcellulose analogues exhibited the thermoreversible gelation in water at around 25 °C as same as that of β-(1 → 4)-linked diblock methylcellulose. Differential scanning calorimetry measurements of 2.0 wt% aqueous solutions of the diblock copolymers revealed that an important structural factor for its thermoreversible gelation was not a β-(1 → 4)-glycosidic linkage between hydrophilic and hydrophobic blocks of diblock methylcellulose, but a sequence of anhydro 2,3,6-tri- O -methyl-glucopyranosyl units and that of unmodified glucopyranosyl ones. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10570-012-9703-7 Authors Atsushi Nakagawa, Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto, 606-8502 Japan Hiroshi Kamitakahara, Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto, 606-8502 Japan Toshiyuki Takano, Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto, 606-8502 Japan Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Thermostable xylanase isoforms T 70 and T 90 were purified and characterized from the xerophytic Opuntia vulgaris plant species. The enzyme was purified to homogeneity employing three consecutive steps. The purified T 70 and T 90 isoforms yielded a final specific activity 134.0 and 150.8 U mg −1 protein, respectively. The molecular mass of these isoforms was determined to be 27 kDa. The optimum pH for the T 70 and T 90 xylanase isoforms was 5.0 and the temperature for optimal activity was 70 and 90 °C, respectively. The Km value of T 70 and T 90 enzyme isoforms was 3.49, 2.1 mg ml −1 , respectively when oat spelt xylan was used as a substrate. The T 70 had a Vmax of 10.4 μmol min −1  mg −1 , and T 90 had a Vmax of 8.9 μmol min −1  mg −1 , respectively. In the presence of 10 mM Co 2+ , and Mn 2+ the activity of T 70 and T 90 isoforms increased, where as 90 % inhibition was noted with of the use 10 mM Hg 2+ , Cd 2+ , Cu 2+ , Zn 2+ while partial inhibition was observed in the presence of Fe 3+ , Ni 2+ , Ca 2+ and Mg 2+ . The T 70 and T 90 isoforms retained nearly 50 % activity in the presence of 2.0 M urea, while use of 40 mM SDS lowered the activity nearly 38–41 %. The substrate specificity of both T 70 and T 90 isoforms showed maximum activity for oat spelt xylan. Western blot, immunodiffusion, and in vitro inhibition assays confirmed reactivity of the T 90 isoform with polyclonal anti-T 90 antibody raised in rabbit, as well as cross-reactivity of the antibody with the T 70 xylanase isoform. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10570-012-9690-8 Authors Jeyaraman Vikramathithan, Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Kalapet, Puducherry 605014, India Sambandam Ravikumar, Department of Chemical Engineering, University of Ulsan, Ulsan, South Korea Pandurangan Muthuraman, Department of Animal Sciences, Chonbuk National University, Chonju, South Korea Gali Nirmalkumar, Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Kalapet, Puducherry 605014, India Sivalingam Shayamala, Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Kalapet, Puducherry 605014, India Kotteazeth Srikumar, Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Kalapet, Puducherry 605014, India Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    This paper describes a method for manufacturing luminescent cellulose fibers. Good optical properties of cellulose fibers under UV-C illumination were achieved by incorporating ZrO 2 (0.5 mol% of Eu 3+ ) stabilized by Y 2 O 3 (7 mol%) into the fiber structure’s particles. Fibers were obtained from 8 wt% cellulose solution in N -methylmorpholine N -oxide (NMMO) with the addition of a luminescent modifier in the range between 0.5 and 10 wt%. The physico-chemical and mechanical parameters and the structure of these fibers were examined. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10570-012-9704-6 Authors Piotr Kulpinski, Department of Man-Made Fibers, Technical University of Lodz, ul. Zeromskiego 116, 90-924 Lodz, Poland Aleksandra Erdman, Department of Man-Made Fibers, Technical University of Lodz, ul. Zeromskiego 116, 90-924 Lodz, Poland Marek Namyslak, Department of Man-Made Fibers, Technical University of Lodz, ul. Zeromskiego 116, 90-924 Lodz, Poland Janusz D. Fidelus, Institute of High Pressure Physics, Polish Academy of Sciences, ul. Sokolowska 29/37, 01-142 Warszawa, Poland Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    The fabrication and evaluation of nanocomposites based on microbial cellulose and polyaniline (PANi) are described. Microbial cellulose, so called, bacterial cellulose (BC) was introduced to interfacial polymerization of aniline. Two different phases based on water and chloroform made it easy for nanosized PANi particles to be synthesized on BC. Without any help of a surfactant or templates, BC played a critical role of supporting the growth of PANi. As a function of aniline concentration, the corresponding PANi content and volume resistivity were checked. From morphological images observed by FE-SEM, PANi nanoparticles were densely arrayed along every fiber of BC. The conjugated backbone of PANi was thought to contribute to the improvements of thermal stability of PANi/BC composites. The stiffness and brittleness of PANi were compensated by more ductile BC, suggesting BC can be a promising substrate for it. By the simple and facile interfacial polymerization, the electrical conductivity of PANi/BC composites reached up to 3.8 × 10 −1  S/cm when 0.32 M of aniline was used. This PANi/BC nanocomposite can be useful in applications requiring biocompatibility and electrical conductivity such as biological and chemical sensors. Content Type Journal Article Category Original Paper Pages 1-8 DOI 10.1007/s10570-012-9705-5 Authors Hyun-Ji Lee, Laboratory of Adhesion and Bio-Composites, Program in Environmental Materials Science, Seoul National University, Seoul, 151-921 Republic of Korea Taek-Jun Chung, Laboratory of Adhesion and Bio-Composites, Program in Environmental Materials Science, Seoul National University, Seoul, 151-921 Republic of Korea Hueck-Jin Kwon, Laboratory of Adhesion and Bio-Composites, Program in Environmental Materials Science, Seoul National University, Seoul, 151-921 Republic of Korea Hyun-Joong Kim, Laboratory of Adhesion and Bio-Composites, Program in Environmental Materials Science, Seoul National University, Seoul, 151-921 Republic of Korea William Tai Yin Tze, Department of Bioproducts and Biosystems Engineering, University of Minnesota, Saint Paul, MN 55108 6130, USA Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    UV- active cellulose fibers were obtained by dry-wet method spinning an 8 % by weight α-cellulose solution in N -methylomorpholine- N -oxide (NMMO) modified by europium-doped gadolinium oxyfluoride Gd 4 O 3 F 6 :Eu 3+ containing 5 mol (%) of the dopant. Photoluminescent nanoparticles were introduced in the in powder form into a polymer matrix during the process of cellulose dissolution in NMMO. The dependencies of emission intensity on excitation energy and the concentration of Gd 4 O 3 F 6 :Eu 3+ nanoparticles in the final cellulosic products were examined by photoluminescence spectroscopy (excitation and emission). The fiber structure was studied by X-ray powder diffraction analysis. The size and dispersity of the nanoparticles in the polymer matrix were evaluated using scanning electron microscopy and X-ray microanalysis. The influence of different concentration particles (in the range from 0.5 to 5 % by weight) on the mechanical properties of the fibers, such as tenacity and elongation at break, were determined. Content Type Journal Article Category Original Paper Pages 1-8 DOI 10.1007/s10570-012-9709-1 Authors Piotr Kulpinski, Department of Man-Made Fibers, Technical University of Lodz, ul. Zeromskiego 116, 90-924 Lodz, Poland Marek Namyslak, Department of Man-Made Fibers, Technical University of Lodz, ul. Zeromskiego 116, 90-924 Lodz, Poland Tomasz Grzyb, Department of Rare Earths, Chemistry Faculty, Adam Mickiewicz University, ul. Grunwaldzka 6, 60-780 Poznan, Poland Stefan Lis, Department of Rare Earths, Chemistry Faculty, Adam Mickiewicz University, ul. Grunwaldzka 6, 60-780 Poznan, Poland Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Cotton yarns bobbins were treated in a water bath with different concentrations of a reactive β-cyclodextrin derivative. To quantify the amount of cyclodextrin fixed on the fiber different analytical methods were tested but none of them was reliable enough in the concentration range under investigation. Therefore, a new analytical method, fast and effective, was developed. From the measurement of cyclodextrin bath exhaustion, the amount of cyclodextrin chemically fixed and that physically adsorbed on the textile substrate was estimated. Two washing cycles were carried out to investigate the cyclodextrin washing fastness. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10570-012-9710-8 Authors R. Peila, Materials Science and Chemical Engineering Department, Politecnico di Torino, C.so Pella 2, 13900 Biella, Italy G. Migliavacca, Materials Science and Chemical Engineering Department, Politecnico di Torino, C.so Pella 2, 13900 Biella, Italy F. Aimone, Materials Science and Chemical Engineering Department, Politecnico di Torino, C.so Pella 2, 13900 Biella, Italy A. Ferri, Materials Science and Chemical Engineering Department, Politecnico di Torino, C.so Pella 2, 13900 Biella, Italy S. Sicardi, Materials Science and Chemical Engineering Department, Politecnico di Torino, C.so Pella 2, 13900 Biella, Italy Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Cellulose whiskers were obtained by means of sulfuric acid hydrolysis of curauá fibers. Before hydrolysis, the natural fibers were treated with an alkaline solution to remove the non-cellulosic content. Fiber degradation evolution and cellulose whisker formation were analyzed by structural and morphological analysis. The original fiber structure underwent a fragmentation mechanism after being exposed for 3 min to sulfuric acid. Cellulose whiskers were lixiviated from the fiber surface after 10 min of hydrolysis, developing two scenarios: one where the whiskers became unattached from the original fiber, and the other which remained attached. The cellulose whiskers presented a needle-like geometry with an approximate diameter of 11 nm and average length of 185 nm, after 30 min of acid hydrolysis. Based on microscopic characterization, a schematic representation of the morphological evolution of the cellulose fibers submitted to acid hydrolysis is proposed. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10570-012-9715-3 Authors Marcia de Oliveira Taipina, Institute of Chemistry, University of Campinas (UNICAMP), P. O. Box 6154, Campinas, SP, Brazil Marcia Maria Favaro Ferrarezi, Institute of Chemistry, University of Campinas (UNICAMP), P. O. Box 6154, Campinas, SP, Brazil Maria do Carmo Gonçalves, Institute of Chemistry, University of Campinas (UNICAMP), P. O. Box 6154, Campinas, SP, Brazil Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Stable aqueous suspensions of cellulose nano-crystals (CNCs) were fabricated from both native and mercerized cotton fibers by sulfuric acid hydrolysis, followed by high-pressure homogenization. Fourier transform infrared spectrometry and wide-angle X-ray diffraction data showed that the fibers had been transformed from cellulose I (native) to cellulose II (mercerized) crystal structure, and these polymorphs were retained in the nanocrystals, giving CNC-I and CNC-II. Transmission electron microscopy showed rod-like crystal morphology for both types of crystals under the given processing conditions with CNC-II having similar width but reduced length. Freeze-dried agglomerates of CNC-II had a much higher bulk density than that of CNC-I. Thermo-gravimetric analysis showed that CNC-II had better thermal stability. The storage moduli of CNC-II suspensions at all temperatures were substantially larger than those of CNC-I suspensions at the same concentration level. CNC-II suspensions and gels were more stable in response to temperature increases. Films of CNC and Poly(ethylene oxide) were tested. Both CNC-I/PEO and CNC-II/PEO composites showed increased tensile strength and elongation at break compared to pure PEO. However, composites with CNC-II had higher strength and elongation than composites with CNC-I. Content Type Journal Article Category Original Paper Pages 1-15 DOI 10.1007/s10570-012-9714-4 Authors Yiying Yue, School of Renewable Natural Resources, Louisiana State University AgCenter, Baton Rouge, LA 70803, USA Chengjun Zhou, School of Renewable Natural Resources, Louisiana State University AgCenter, Baton Rouge, LA 70803, USA Alfred D. French, USDA ARS, 1100 Robert Lee Blvd., New Orleans, LA 70124, USA Guan Xia, School of Renewable Natural Resources, Louisiana State University AgCenter, Baton Rouge, LA 70803, USA Guangping Han, Material Science and Engineering College, Northeast Forestry University, 26 Hexing Rd, Harbin, 150040 China Qingwen Wang, Material Science and Engineering College, Northeast Forestry University, 26 Hexing Rd, Harbin, 150040 China Qinglin Wu, School of Renewable Natural Resources, Louisiana State University AgCenter, Baton Rouge, LA 70803, USA Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    The kinetics of periodate oxidation of cellulose was followed by exploiting the β-alkoxy degradation of oxidised units in alkaline medium, that brings about a decrease of viscometric degree of polymerisation. The parallel strong weight loss after NaOH treatment indicates a non-random mechanism of oxidation. The obtained results are interpreted on the basis of an appositely derived kinetic model that can be applied to other mechanisms of bulk and surface degradation. Content Type Journal Article Category Original Paper Pages 1-8 DOI 10.1007/s10570-012-9717-1 Authors Paolo Calvini, Istituto per la Tutela delle opere Grafiche (ITOG), Via Pietro Sola 29, 31059 Zero Branco, Treviso, Italy Andrea Gorassini, Dipartimento di Storia e Tutela dei Beni Culturali, Università degli Studi di Udine, Via Petracco 8, 33100 Udine, Italy Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Nanofibrillated cellulose offers new technological solutions for the development of paper products. Here, composites of nanofibrillated cellulose (NFC) and Ag nanoparticles (NP) were prepared for the first time via the electrostatic assembly of Ag NP (aqueous colloids) onto NFC. Distinct polyelectrolytes have been investigated as macromolecular linkers in order to evaluate their effects on the building-up of Ag modified NFC and also on the final properties of the NFC/Ag composite materials. The NFC/Ag nanocomposites were first investigated for their antibacterial properties towards S. aureus and K. pneumoniae microorganisms as compared to NFC modified by polyelectrolytes linkers without Ag. Subsequently, the antibacterial NFC/Ag nanocomposites were used as fillers in starch based coating formulations for Eucalyptus globulus -based paper sheets. The potential of this approach to produce antimicrobial paper products will be discussed on the basis of complementary optical, air barrier and mechanical data. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10570-012-9713-5 Authors Natércia C. T. Martins, CICECO, Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal Carmen S. R. Freire, CICECO, Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal Ricardo J. B. Pinto, CICECO, Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal Susana C. M. Fernandes, CICECO, Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal Carlos Pascoal Neto, CICECO, Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal Armando J. D. Silvestre, CICECO, Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal Jessica Causio, INNOVHUB-Paper Division, Piazza Leonardo Da Vinci, 16, 20133 Milan, Italy Giovanni Baldi, Centro Ricerche Colorobbia, Via Pietramarina, 53, 50053 Sovigliana, Italy Patrizia Sadocco, INNOVHUB-Paper Division, Piazza Leonardo Da Vinci, 16, 20133 Milan, Italy Tito Trindade, CICECO, Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    In order to improve the spinning efficiency, the spinning experiments with cellulose/1-butyl-3-methylimidazolium chloride solution were done whilst increasing spinning speed. It was found that the tenacity and initial modulus of regenerated cellulose fibers increased but the elongation at break decreased slightly with increasing spinning speed at constant draw ratio. Further, the synchrotron wide-angle X-ray diffraction and small-angle X-ray scattering were carried out to illustrate the relationship between the structure and the mechanical properties. It was shown that the crystal orientation, crystallinity, amorphous orientation factor as well as orientation of the microvoids along the fiber increased with the spinning speed as the diameter of the microvoids in the fiber decreased. From the analysis of the spinline stress, it is clear that the spinline stress increased when both extruding and draw speed increased at constant draw ratio. This resulted in the improvement of supramolecular structure and mechanical properties of the regenerated cellulose fibers. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10570-012-9716-2 Authors Guansen Jiang, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, 201620 China Ye Yuan, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, 201620 China Baochun Wang, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, 201620 China Xuemin Yin, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, 201620 China Kanukai Susan Mukuze, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, 201620 China Weifeng Huang, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, 201620 China Yumei Zhang, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, 201620 China Huaping Wang, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, 201620 China Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Cationic polyelectrolytes (polyallylamine and polyvinylamine with different molecular masses) were adsorbed onto lignocellulosic fibres from unbleached and unbeaten spruce chemical fibres with different kappa numbers to investigate the effects on the mechanical properties of the final paper materials. Adsorption isotherms were first established to determine the maximum quantity of polymer that could be adsorbed onto each type of fibre. Paper sheets were then made with different amounts of added polyelectrolyte, and the structural and mechanical properties of the sheets were investigated, as well as the effect of an extra heating. The use of fibres with different kappa numbers led to different responses in terms of adsorption, and thus to differences in the mechanical properties of the resulting sheets. The tensile strength index was significantly increased (almost 50 % improvement in the best case) as a consequence of this polyelectrolyte adsorption onto the fibres, even at as low an adsorption level as 2 mg/g. The heating of paper sheets for 10 min at 160 °C was also shown to improve the tensile strength index by about 10 % for pulps with high kappa number. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10570-012-9712-6 Authors Andrew Marais, Division of Fibre Technology, School of Chemical Science and Engineering, KTH Royal Institute of Technology, Stockholm, 100 44 Stockholm, Sweden Lars Wågberg, Division of Fibre Technology, School of Chemical Science and Engineering, KTH Royal Institute of Technology, Stockholm, 100 44 Stockholm, Sweden Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Superabsorbents hydrogel nanocomposites based on starch- g -poly(sodium acrylate) and cellulose nanowhiskers (CNWs) were synthesized. A set of experiments was performed to evaluate the influence of some factors such as NaAc/starch mass ratio, crosslinker, and nanowhiskers amount in the swelling capacity and swelling kinetics. Increasing the NaAc/starch mass ratio up to 7 leads to an increase in the water uptake at a maximum value, however, higher ratios decreased that value due to the increase of crosslinking points. Similarly, the incorporation of CNWs up to 10 wt% provided an improvement in the swelling due to the hydrophilic groups from cellobiose units. Further, the incorporation of CNWs diminishes the water uptake. Besides, the CNWs improved the mechanical properties. SEM images showed that CNWs increase the average porous size of composites. The composites presented good responsive behavior in relation to pH and salt presence allowing those materials suitable for many potential applications. Content Type Journal Article Category Original Paper Pages 1-13 DOI 10.1007/s10570-012-9711-7 Authors Cristiane Spagnol, Departamento de Química, Universidade Estadual de Maringá, Av. Colombo, 5790, 87020-900 Maringá, PR, Brazil Francisco H. A. Rodrigues, Departamento de Química, Universidade Estadual de Maringá, Av. Colombo, 5790, 87020-900 Maringá, PR, Brazil Antonio G. B. Pereira, Departamento de Química, Universidade Estadual de Maringá, Av. Colombo, 5790, 87020-900 Maringá, PR, Brazil André R. Fajardo, Departamento de Química, Universidade Estadual de Maringá, Av. Colombo, 5790, 87020-900 Maringá, PR, Brazil Adley F. Rubira, Departamento de Química, Universidade Estadual de Maringá, Av. Colombo, 5790, 87020-900 Maringá, PR, Brazil Edvani C. Muniz, Departamento de Química, Universidade Estadual de Maringá, Av. Colombo, 5790, 87020-900 Maringá, PR, Brazil Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    In this paper, a novel type of hemicellulosic derivative containing polymerizable double bonds (C=C) was synthesized by chemical reaction of xylan-rich hemicelluloses and glycidyl methacrylate (GMA) in dimethyl sulfoxide (DMSO) in presence of catalysts. The chemical structure, reaction mechanism, and rheological properties of the derivative were investigated by means of FT-IR, 1 H and 13 C-NMR, DEPT 135 NMR, GC–MS and rheometer. The influence of the reaction conditions including reaction time, temperature, catalysts, and the amount of reagents on the degree of substitution were investigated in detail. Results showed that the chemical reaction of xylan-rich hemicelluloses with GMA was transesterification, which resulted in direct attachment of methacrylate (MA) groups to xylan-rich hemicelluloses, instead of GMA. A maximum degree of substitution of 0.94 could be achieved under the optimum reaction condition (40 °C, 1.8 equiv of GMA to per xylose unit, 36 h, 20 % DMAP). Results from rheological analysis indicated that the aqueous solutions of the methacrylated xylan-rich hemicelluloses (MAXH; 0.5, 1.0 and 2.0 wt%) exhibited typical shear-thinning behavior in the range of shear rates tested. The viscoelasticity of MAXH solutions increased with the increasing concentration and DS. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10570-012-9718-0 Authors Xinwen Peng, State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, China Junli Ren, State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, China Linxin Zhong, Institute of Biomass Chemistry and Technology, Beijing Forestry University, Beijing, China Runcang Sun, Institute of Biomass Chemistry and Technology, Beijing Forestry University, Beijing, China Wenbin Shi, State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, China Bojie Hu, State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, China Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    The structure and crystallization of carefully isolated sub-elementary fibrils (SEFs) of bacterial cellulose have been investigated using TEM, WAXD, and high-resolution solid-state 13 C NMR. The addition of a suitable amount of fluorescent brightener (FB) to the incubation medium of Acetobacter xylinum effectively suppressed the aggregation of the SEFs into the microfibrils, as previously reported. However, this study confirmed for the first time that serious structural change in the SEFs occurs during the removal of excess FB by washing with buffer solutions having pH values higher than 6 or with the alkaline aqueous solution that was frequently used in previous studies. In contrast, the isolation of unmodified SEFs was successfully performed by utilizing a washing protocol employing pH 7 citrate–phosphate buffer solution containing 1% sodium dodecyl sulfate. High-resolution solid-state 13 C NMR and WAXD measurements revealed that the SEFs thus isolated are in the noncrystalline state in which the pyranose rings of the almost parallel cellulose chains appear to be stacked on each other. The respective CH 2 OH groups of the SEFs adopt the gt conformation instead of the tg conformation found in cellulose I α and I β crystals, and undergo significantly enhanced molecular motion in the absence of intermolecular hydrogen bonding associated with these groups. The main chains are also subject to rapid motional fluctuations while maintaining the parallel orientation of the respective chains, indicating that the SEFs have a liquid crystal-like structure with high molecular mobility. Moreover, the SEFs crystallize into cellulose I β when the FB molecules that may adhere to the surface of the SEFs are removed by extraction with boiling 70 v/v% ethanol and 0.1N NaOH aqueous solution. On the basis of these results, the crystallization of the SEFs into the I α and I β forms is discussed, including the possible formation of the crystalline-noncrystalline periodic structure in native cellulose. Content Type Journal Article Category Original Paper Pages 1-15 DOI 10.1007/s10570-012-9678-4 Authors Shinji Suzuki, Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan Furitsu Suzuki, Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan Yasumasa Kanie, Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan Koji Tsujitani, Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan Asako Hirai, Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan Hironori Kaji, Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan Fumitaka Horii, Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Hybrid organic–inorganic coatings containing ammonium polyphosphate (APP), chitosan and silica have been deposited on polyester-cotton blends (PET-CO), exploiting the layer by layer assembly. To this aim, two different complex architectures (namely, chitosan/APP bilayers plus silica/silica bilayers or silica/silica/chitosan/APP quadlayers) have been thoroughly investigated. The effect of their morphologies on the flame retardancy properties of the fabrics (flammability and combustion behaviour) has been assessed. More specifically, some of the above complex architectures exhibited significant enhancements concerning flammability (i.e. the suppression of afterglow, together with a considerable final residue increase) and combustion behaviour as evidenced by cone calorimeter tests. A close relationship between the overall flame retardancy properties of the blends and the level of dishomogeneity of the LbL architectures has been shown. Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10570-012-9682-8 Authors Jenny Alongi, Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, sede di Alessandria, Viale Teresa Michel 5, 15121 Alessandria, Italy Federico Carosio, Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, sede di Alessandria, Viale Teresa Michel 5, 15121 Alessandria, Italy Giulio Malucelli, Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, sede di Alessandria, Viale Teresa Michel 5, 15121 Alessandria, Italy Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Our aim was to characterise the suspension rheology of microfibrillated cellulose (MFC) in relation to flocculation of the cellulose fibrils. Measurements were carried out using a rotational rheometer and a transparent cylindrical measuring system that allows combining visual information to rheological parameters. The photographs were analyzed for their floc size distribution. Conclusions were drawn by comparing the photographs and data obtained from measurements. Variables selected for examination of MFC suspensions were degree of disintegration of fibres into microfibrils, the gap between the cylinders, sodium chloride concentration, and the effects of changing shear rate during the measurement. We studied changes in floc size under different conditions and during network structure decomposition. At rest, the suspension consisted of flocs sintered together into a network. With shearing, the network separated first into chain-like floc formations and, upon further shear rate increase, into individual spherical flocs. The size of these spherical flocs was inversely proportional to the shear rate. Investigations also confirmed that floc size depends on the geometry gap, and it affects the measured shear stress. Furthermore, suspension photographs revealed an increasing tendency to aggregation and wall depletion with sodium chloride concentration of 10 −3 M and higher. Content Type Journal Article Pages 1-13 DOI 10.1007/s10570-012-9661-0 Authors Eve Saarikoski, School of Chemical Technology, Polymer Technology, Aalto University, P.O. Box 16100, 00076 Aalto, Espoo, Finland Tapio Saarinen, School of Chemical Technology, Polymer Technology, Aalto University, P.O. Box 16100, 00076 Aalto, Espoo, Finland Juha Salmela, VTT Processes, Koivurannantie 1, P.O. Box 1603, 40101 Jyväskylä, Finland Jukka Seppälä, School of Chemical Technology, Polymer Technology, Aalto University, P.O. Box 16100, 00076 Aalto, Espoo, Finland Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    To clarify the interaction between the –OH groups of cellulose and NaOH/urea in aqueous solutions, methylcellulose (MC) was used as solute to study its solution properties at low temperature. Dynamic light scattering, 13 C NMR spectroscopy, differential scanning calorimetry, and transmission electron microscopy (TEM) were used to characterize the MC macromolecular size and intermolecular interactions between MC and solvent molecules. The results revealed that MC existed mainly as individual molecules in the NaOH/urea aqueous solution prepared by freeze-thawing process, whereas aggregates occurred in the MC solution prepared at room temperature. DLS further confirmed that MC existed mainly as individual flexible chains in the solution treated at low temperature. TEM images showed the sphere-like coil appearance of the MC macromolecules in the solution prepared at low temperature. Therefore, the strong interaction between –OH groups of MC and solvent occurred at low temperature, leading to the formation of the imperfect inclusion complex through hydrogen bonding network between MC, NaOH, urea and water. Content Type Journal Article Pages 1-8 DOI 10.1007/s10570-012-9669-5 Authors Zhiwei Jiang, Department of Chemistry, Wuhan University, Wuhan, 430072 China Ang Lu, Department of Chemistry, Wuhan University, Wuhan, 430072 China Jinping Zhou, Department of Chemistry, Wuhan University, Wuhan, 430072 China Lina Zhang, Department of Chemistry, Wuhan University, Wuhan, 430072 China Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    A method is presented which enables analysis of lignin precipitated on the surface of kraft pulp fibers. As experimental input, high-resolution atomic force microscopy phase images of the fiber surfaces have been recorded in tapping mode. A digital image analysis procedure—based on the watershed algorithm—is applied to distinguish between cellulose fibrils and the precipitated lignin. In this way, size distributions for the diameter of lignin precipitates on pulp fiber surfaces can be obtained. In an initial application of the method, three softwood kraft pulps were analyzed: a black liquor cook with a very high content of precipitated lignin, a bleached pulp where nearly no precipitated lignin is visible and an unbleached industrial pulp. The proposed method is suggested as an appropriate tool to investigate the kinetics of lignin precipitation and the structure of lignin precipitates in pulping and bleaching. Content Type Journal Article Pages 1-9 DOI 10.1007/s10570-012-9667-7 Authors Franz J. Schmied, Institute of Physics, Montanuniversität Leoben, 8700 Leoben, Austria Christian Teichert, Institute of Physics, Montanuniversität Leoben, 8700 Leoben, Austria Lisbeth Kappel, Institute for Paper, Pulp and Fiber Technology, Graz University of Technology, 8010 Graz, Austria Ulrich Hirn, Institute for Paper, Pulp and Fiber Technology, Graz University of Technology, 8010 Graz, Austria Robert Schennach, Institute of Solid State Physics, Graz University of Technology, 8010 Graz, Austria Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    The susceptibility of (1) never-dried and (2) freeze-dried bacterial cellulose (BC) towards organic acid esterification is reported in this work. When never-dried BC (BC which was solvent exchanged from water through methanol into pyridine) was modified with hexanoic acid, it was found that the degree of substitution (DS) was significantly lower than that of hexanoic acid modified freeze-dried BC. The crystallinity of freeze-dried BC hexanoate was found to be significantly lower compared to neat BC and never-dried BC hexanoate. This result, along with the high DS indicates that significant bulk modification occurred during the esterification of freeze-dried BC. Such results were not observed for never-dried BC hexanoate. All these evidence point towards to fact that freeze-dried BC was more susceptible to organic acid esterification compared to never-dried BC. A few hypotheses were explored to explain the observed behaviour and further investigated to elucidate our observation; the effect of residual water in cellulose, the accessibility of hydroxyl groups and the crystal structure of never-dried and freeze-dried BC on the susceptibility of cellulose fibrils to esterification, respectively. However, the investigation of these hypotheses raised more questions and we are still left with the main question; why do BC nanofibres behave differently when modifying freeze-dried BC or never-dried BC? Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10570-012-9680-x Authors Koon-Yang Lee, Polymer and Composites Engineering (PaCE) Group, Department of Chemical Engineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK Alexander Bismarck, Polymer and Composites Engineering (PaCE) Group, Department of Chemical Engineering, Imperial College London, South Kensington Campus, SW7 2AZ London, UK Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    A computer docking study was carried out on the (110) crystal surface of the cellulose Iα crystal model for the carbohydrate binding module (CBM) of cellobiohydrolase Cel6A, which is produced by the filamentous fungus Trichoderma reesei . Three-dimensional structures of the CBM were constructed by the homology modeling method using the Cel7A CBM, which is another cellobiohydrolase from T. reesei , as a template, and refined by molecular dynamics calculations in the solution state. Among the three models tested, those with three disulfide bonds were selected for a docking analysis. The binding free energy maps represented changes in non-covalent interactions and solvation free energies with respect to the CBM position. These indicated two minimum positions within the unit cell for both the parallel and antiparallel orientation modes of the CBM with respect to the cellulose fiber axis. Molecular dynamics calculations under an explicit solvent system were performed for the four complex models derived from the minimum positions of the binding free energy maps. The complex models with CBM in the parallel orientation had the lowest binding energies. Content Type Journal Article Pages 1-11 DOI 10.1007/s10570-012-9671-y Authors Hirohide Shiiba, Department of Applied Chemistry, Faculty of Engineering, University of Miyazaki, Nishi 1-1, Gakuen-kibanadai, Miyazaki, 889-2192 Japan Sachio Hayashi, Department of Applied Chemistry, Faculty of Engineering, University of Miyazaki, Nishi 1-1, Gakuen-kibanadai, Miyazaki, 889-2192 Japan Toshifumi Yui, Department of Applied Chemistry, Faculty of Engineering, University of Miyazaki, Nishi 1-1, Gakuen-kibanadai, Miyazaki, 889-2192 Japan Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    This work describes for the first time the synthesis and characterization of new promising materials based on cellulose (Cel) and cellulose acetate (Celac), previously modified with aluminum oxide (CelAl and CelacAl) and post functionalized with 1,4-diazabicyclo [2.2.2] octane-n-propyltrimethoxysilane chloride (SiDbCl 2 ), resulting the chemically modified hybrid materials CelAl/SiDbCl 2 and CelacAl/SiDbCl 2 . The materials have shown to be useful in the adsorption of CuCl 2 from ethanol, presenting high effective adsorption capacity. In the adsorption process, the copper ions diffuse into the solid solution interface and are retained as anionic complexes CuCl 3 − or CuCl 4 2− . An expressive effective adsorption capacity t Q , as well as the stability constants β 1 and β 2 , were found for both adsorbents: (a) CelAl/DbCl 2 : t Q  = 0.33 × 10 −3  mol g −1 , log β 1  = 4.23 (±0.04) and log β 2  = 6.99 (±0.03); (b) CelacAl/DbCl 2 : t Q  = 0.48 × 10 −3  mol g −1 , log β 1  = 5.1 (±0.1) and log β 2  = 8.3 (±0.1). Both adsorbent materials are potentially useful in the pre-concentration and further analysis of Cu(II) present in trace amounts in ethanol, extensively used as an automotive fuel in Brazil. Regeneration of the adsorbents requires a very simple procedure consisting in their immersion in aqueous solution which causes the immediate release of the Cu(OH 2 ) n 2+ species to the solution phase. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10570-012-9657-9 Authors Hérica A. Magosso, Department of Chemistry, Santa Catarina Federal University, PO Box 476, Florianópolis, SC 88040-900, Brazil Natália Fattori, Institute of Chemistry, State University of Campinas, UNICAMP, PO Box 6154, Campinas, SP 13083-970, Brazil Leliz T. Arenas, Institute of Chemistry, Rio Grande do Sul Federal University, PO Box 15003, Porto Alegre, RS 91501-970, Brazil Yoshitaka Gushikem, Institute of Chemistry, State University of Campinas, UNICAMP, PO Box 6154, Campinas, SP 13083-970, Brazil Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Nanofibrillated cellulose (NFC) is increasingly utilized in materials and biomedical applications consequently increasing interest in the modification of its surface properties. Besides modification using polyelectrolytes and polysaccharides, NFC can be combined with solid particles enabling formation of fibril network loaded with particles. Use of particles enabling easy functionalization could be beneficial for the development of hybrid structures, and lead to preparation of nanocomposites and functional materials. In order to explore interactions related to preparation of such structures, the interactions between nanosized precipitated calcium carbonate (nanoPCC) and nanoclay particles and NFC were examined by observing adsorption of the particles on NFC substrate using a quartz crystal microbalance with dissipation monitoring (QCM-D) and atomic force microscopy (AFM) imaging. By a treatment with carboxymethylated cellulose (CMC), the anionicity of the NFC substrate could be increased, providing an additional tool to affect the interplay between NFC and the inorganic particles. For slightly cationic nanoPCC particles an increase in the anionicity of the NFC by the CMC treatment increased the affinity, while the opposite was true for anionic nanoclay. Additionally, for interactions between nanoclay and NFC, dispersion stability was an important factor. QCM-D was successfully used to examine the adsorption characteristics of nanoparticles although the technique is commonly used to study the adsorption of thin polymer layers. Distinct adsorption characteristics were observed depending on the nanoparticle used; nanoclay particles deposited as a thin layer, whereas nanoPCC particles formed clusters. Content Type Journal Article Pages 1-14 DOI 10.1007/s10570-012-9656-x Authors Tiina Nypelö, Department of Forest Products Technology, Aalto University School of Chemical Technology, P.O. Box 16300, 00076 Aalto, Finland Hanna Pynnönen, Department of Forest Products Technology, Aalto University School of Chemical Technology, P.O. Box 16300, 00076 Aalto, Finland Monika Österberg, Department of Forest Products Technology, Aalto University School of Chemical Technology, P.O. Box 16300, 00076 Aalto, Finland Jouni Paltakari, Department of Forest Products Technology, Aalto University School of Chemical Technology, P.O. Box 16300, 00076 Aalto, Finland Janne Laine, Department of Forest Products Technology, Aalto University School of Chemical Technology, P.O. Box 16300, 00076 Aalto, Finland Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    TEMPO-oxidized cellulose nanofibers (TOCN) were obtained from commercial Norway spruce and mixed Eucalyptus cellulose pulps using TEMPO/sodium bromide (NaBr)/sodium hypochlorite (NaClO) system at pH 10 and 22 °C. After reaction, the fibrillated TEMPO-oxidized celluloses were used for preparation of self-standing films and casting of laminate films on 50 μm thick polyethylene terephthalate. Significant differences between N. spruce and Eucalyptus TOCN were registered. The tensile strength of the films showed a maximum value for spruce samples oxidized with addition of 10 mmol g −1 of NaClO. Oxygen permeability decreased with increasing oxidation levels, being lower for N. spruce TOCN compared to Eucalyptus. Content Type Journal Article Pages 1-7 DOI 10.1007/s10570-012-9664-x Authors Galina Rodionova, Department of Chemical Engineering, Norwegian University of Science and Technology, 7491 Trondheim, Norway Tsuguyuki Saito, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657 Japan Marianne Lenes, Paper and Fibre Research Institute, 7491 Trondheim, Norway Øyvind Eriksen, Paper and Fibre Research Institute, 7491 Trondheim, Norway Øyvind Gregersen, Department of Chemical Engineering, Norwegian University of Science and Technology, 7491 Trondheim, Norway Hayaka Fukuzumi, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657 Japan Akira Isogai, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657 Japan Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    The microstructure and chemical composition of alfa ( Stipa tenacissima ) were investigated. The polysaccharide and lignin contents were around 70 and 20 wt%, respectively. From the bleached and delignified fibers, two types of nanosized cellulosic particles were extracted, namely cellulose nanocrystals and microfibrillated cellulose (MFC). The former correspond typically to the elementary crystallite units of the cellulose fibers, with a rod-like morphology and an aspect ratio of about 20. The latter, mechanically disintegrated from oxidized bleached fibres, presents an entangled fibrillar structure with widths in the range 5-20 nm. The reinforcing potential of the ensuing nanoparticles was investigated by casting a mixture of acrylic latex and aqueous dispersion of cellulose nanoparticles. Thermo-mechanical analysis revealed a huge enhancement of the stiffness above the glass transition of the matrix. Significant differences in the mechanical reinforcing capability of the nanoparticles were reported. Content Type Journal Article Pages 1-11 DOI 10.1007/s10570-012-9662-z Authors Ayman Ben Mabrouk, Laboratoire Sciences des Matériaux et Environnement, LMSE, University of Sfax, BP 802-3018 Sfax, Tunisia Hamid Kaddami, Laboratoire de Chimie Organométallique et Macromoléculaire - Matériaux Composites, Cadi Ayyad University, Faculty of Sciences and Technologies of Marrakesh, Avenue Abdekrim Elkhattabi, BP549, Marrakesh, Morocco Sami Boufi, Laboratoire Sciences des Matériaux et Environnement, LMSE, University of Sfax, BP 802-3018 Sfax, Tunisia Fouad Erchiqui, Laboratoire de Plasturgie et Nanocomposites, Université de Québec en Abitibi-Témiscaminque, Boulevard de l’Université, Rouyn-Noranda, QC J9X5E4, Canada Alain Dufresne, The International School of Paper, Print Media and Biomaterials (Pagora), Grenoble Institut of Technology, BP65, 38402 Saint Martin d’Hères Cedex, France Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Orientation birefringence and its wavelength dispersion for various types of cellulose esters are reviewed. Cellulose esters such as cellulose acetate propionate and cellulose acetate butyrate show positive orientation birefringence with extraordinary wavelength dispersion, which is determined mainly by the ester groups rather than the main chains. The acetyl group provides negative orientation birefringence with strong ordinary wavelength dispersion, whereas the propionyl and butyryl groups give positive orientation birefringence with weak wavelength dispersion. Although all groups show ordinary wavelength dispersion, the summation of their orientation birefringences gives extraordinary dispersion. Moreover, the wavelength dispersion is dependent on the stretching ratio due to the difference in the orientation relaxation of each group. On the contrary, cellulose triacetate (CTA) shows negative birefringence with ordinary wavelength dispersion because it has no positive contribution. However, doping a plasticizer having positive orientation birefringence changes the orientation birefringence of CTA from negative to positive, and the wavelength dispersion from ordinary to extraordinary. This is attributed to the cooperative orientation of plasticizer molecules to the stretching direction with CTA chains, known as nematic interaction upon a hot drawing process. Content Type Journal Article Category Review Paper Pages 1-13 DOI 10.1007/s10570-012-9660-1 Authors Masayuki Yamaguchi, School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa, 923-1292 Japan Mohd Edeerozey Abd Manaf, School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa, 923-1292 Japan Kultida Songsurang, School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa, 923-1292 Japan Shogo Nobukawa, School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa, 923-1292 Japan Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    The modification of bleached never-dried cellulose fibers was studied under controlled compression and shearing conditions. Fibers were further treated in a high-intensity mixing device in low-consistency to determine if the fiber structure was weakened in the in-pad attrition. The difference between the development of the softwood and hardwood fibers was examined. The fiber properties were analyzed using a fiber morphology analyzer, fractional fiber analysis and an electron microscope. The results indicate that the shearing under the controlled compression at high consistency modified the softwood and hardwood fibers already at low-energy consumptions. The fiber length and width decreased, and the formation of curls and kinks was pronounced. However, the intensive mixing after in-pad attrition revealed that the fiber structure was not weakened under compression and shear forces; conversely, the fiber cell wall was more resistant for the intensive mixing. When comparing the results for hardwood and softwood fibers, the softwood fibers were more modified during in-pad attrition, whereas the fiber wall strengthening was more significant in the hardwood fibers. Content Type Journal Article Pages 1-11 DOI 10.1007/s10570-012-9670-z Authors Kaarina Kekäläinen, Fibre and Particle Engineering Laboratory, Department of Process and Environmental Engineering, University of Oulu, P.O. Box 4300, 90014 Oulu, Finland Mirja Illikainen, Fibre and Particle Engineering Laboratory, Department of Process and Environmental Engineering, University of Oulu, P.O. Box 4300, 90014 Oulu, Finland Jouko Niinimäki, Fibre and Particle Engineering Laboratory, Department of Process and Environmental Engineering, University of Oulu, P.O. Box 4300, 90014 Oulu, Finland Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    A new nonlinear isothermal sorption model, incorporating Donnan equilibrium and electrical neutrality in the classical sorption model of direct dyes onto cellulosic substrates, as model adsorbates, is proposed. The nonlinear isothermal model was used to simulate equilibrium sorption of adsorbates containing ionic charges ( z ) of −2 to −4 on cellulose adsorbents at various temperature ( T ) and sodium chloride concentrations ([NaCl]). A detailed analysis of simulation results demonstrates that results based on the nonlinear sorption model highly agree with those based on the log-linear sorption model when the deviation in the concentration of sodium ions in the aqueous solution ([Na + ] S ) relative to [NaCl] used in the sorption system is restricted to 〈5.0%. Compared to the log-linear model, the nonlinear model avoids using graphical techniques that are relatively insensitive for determining important sorption parameters such as the internal accessible volume ( V ) and the standard affinity associated with sorption (−Δμ°). The nonlinear sorption model was used to examine the correlation of fit for previously reported sorption data. The model parameters V and −Δ μ° based on curve fits were used to estimate V for cellulose as well as −Δ μ° . The values were found to match those based on the conventional log-linear model when deviations of [Na + ] S relative to [\text Na + ] S   were below 5%. The nonlinear model therefore provides a convenient and accurate technique to interpret the sorption of a range of anionic adsorbates on cellulosic substrates. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10570-012-9675-7 Authors Changhai Xu, Fiber and Polymer Science Program, North Carolina State University, Raleigh, NC 27695-8301, USA Renzo Shamey, Fiber and Polymer Science Program, North Carolina State University, Raleigh, NC 27695-8301, USA Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Aqueous suspensions of cellulose nanocrystals (NCC) produced by sulfuric acid hydrolysis of natural cellulose fibres display a number of unique properties. In addition to forming equilibrium chiral nematic phases above some critical concentration, cellulose nanocrystal suspensions tend to gel or aggregate if the stability of the suspension decreases, for example because of a decrease in the surface charge density of sulfate ester groups, or a change in the properties of the suspending medium. Direct incorporation of unmodified nanocrystals into organic media usually leads to aggregation. We have found that it is possible to circumvent this difficulty and form clear thixotropic gels of unmodified NCC in glycerol, by careful evaporation of water from aqueous glycerol suspensions of NCC. The physical gels form at a fairly low (〈3 wt%) concentrations of cellulose. The initial composition of the suspension, the temperature and rate of evaporation, and the time resting at room temperature all influence the formation of thixotropic gels. Desulfation of the acid-form nanocrystals, enhanced in the glycerol-rich suspensions, is shown to be a key step in this gelation process. Content Type Journal Article Category Original Paper Pages 1-8 DOI 10.1007/s10570-012-9679-3 Authors Annie Dorris, Department of Chemistry, McGill University, Pulp and Paper Building, 3420 University Street, Montreal, QC H3A 2A7, Canada Derek G. Gray, Department of Chemistry, McGill University, Pulp and Paper Building, 3420 University Street, Montreal, QC H3A 2A7, Canada Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    A new type of micro/nanocomposite was made by using only micro fibrillated cellulose and inorganic fillers. This composite structure can contain up to 90% fillers being still mechanically stable and flexible. Calendering can be used to produce dense structures with extremely smooth surface. To study the effect of filler shape and type, both kaolin and precipitated calcium carbonate (PCC) based sheets were examined. Microscopy (cross-sectional and surface SEM images) and mechanical and morphological properties, including strength properties, surface roughness and dimensional stability as a function of moisture were analysed. After calendering the surface of the PCC containing sheets was smoother than that of photopaper and in the same level as reference plastic film Mylar A. The dimensional stability of the sheets was clearly better than that of paper sheets. The combination of a good dimensional stability with low surface roughness makes these structures potential for printed electronics applications, in which they could replace oil-based plastic substrates. Suitability for printed electronic applications was tested by inkjet printing conductors with silver nanoparticle ink. The sheet resistances of conductors printed on kaolin based sheets were close to those printed on plastic Mylar A film. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10570-012-9677-5 Authors K. Torvinen, VTT Technical Research Center of Finland, P.O. Box 1000, 02044 VTT, Espoo, Finland J. Sievänen, VTT Technical Research Center of Finland, P.O. Box 1000, 02044 VTT, Espoo, Finland T. Hjelt, VTT Technical Research Center of Finland, P.O. Box 1000, 02044 VTT, Espoo, Finland E. Hellén, VTT Technical Research Center of Finland, P.O. Box 1000, 02044 VTT, Espoo, Finland Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    The present work is inserted into the broad context of the upgrading of lignocellulosic fibers. Sisal was chosen in the present study because more than 50% of the world’s sisal is cultivated in Brazil, it has a short life cycle and its fiber has a high cellulose content. Specifically, in the present study, the subject addressed was the hydrolysis of the sisal pulp, using sulfuric acid as the catalyst. To assess the influence of parameters such as the concentration of the sulfuric acid and the temperature during this process, the pulp was hydrolyzed with various concentrations of sulfuric acid (30–50%) at 70 °C and with 30% acid (v/v) at various temperatures (60–100 °C). During hydrolysis, aliquots were withdrawn from the reaction media, and the solid (non-hydrolyzed pulp) was separated from the liquid (liquor) by filtering each aliquot. The sugar composition of the liquor was analyzed by HPLC, and the non-hydrolyzed pulps were characterized by viscometry (average molar mass), and X-ray diffraction (crystallinity). The results support the following conclusions: acid hydrolysis using 30% H 2 SO 4 at 100 °C can produce sisal microcrystalline cellulose and the conditions that led to the largest glucose yield and lowest decomposition rate were 50% H 2 SO 4 at 70 °C. In summary, the study of sisal pulp hydrolysis using concentrated acid showed that certain conditions are suitable for high recovery of xylose and good yield of glucose. Moreover, the unreacted cellulose can be targeted for different applications in bio-based materials. A kinetic study based on the glucose yield was performed for all reaction conditions using the kinetic model proposed by Saeman. The results showed that the model adjusted to all 30–35% H 2 SO 4 reactions but not to greater concentrations of sulfuric acid. The present study is part of an ongoing research program, and the results reported here will be used as a comparison against the results obtained when using treated sisal pulp as the starting material. Content Type Journal Article Category Original Paper Pages 1-18 DOI 10.1007/s10570-012-9674-8 Authors Mauricio P. de Paula, Macromolecular Materials and Lignocellulosic Fibers Group, Institute of Chemistry of São Carlos, University of São Paulo, CP 780, São Carlos, São Paulo 13560-970, Brazil Talita M. Lacerda, Macromolecular Materials and Lignocellulosic Fibers Group, Institute of Chemistry of São Carlos, University of São Paulo, CP 780, São Carlos, São Paulo 13560-970, Brazil Márcia D. Zambon, Macromolecular Materials and Lignocellulosic Fibers Group, Institute of Chemistry of São Carlos, University of São Paulo, CP 780, São Carlos, São Paulo 13560-970, Brazil Elisabete Frollini, Macromolecular Materials and Lignocellulosic Fibers Group, Institute of Chemistry of São Carlos, University of São Paulo, CP 780, São Carlos, São Paulo 13560-970, Brazil Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Blend hydrogels composed of carboxymethyl chitosan (CMCh) and poly (acrylonitrile) (PAN) were synthesized via crosslinking method. Several analyses were made to investigate both physical and thermal properties of CMCh/PAN hydrogels like; FTIR, scanning electron microscope, XRD and thermogravimetric analysis (TGA). TGA results showed that CMCh/PAN hydrogels are thermally more stable than CMCh and their thermal stability increases as PAN content increases in the hydrogel. Moreover, the swelling behavior of CMCh/PAN hydrogels was studied in different buffer solutions. It was found that CMCh/PAN hydrogels swell much more than PAN especially at pH 9. The hydrogels sorption for different dyestuff and various metal ions like; Cu 2+ , Cd 2+ and Co 2+ were also studied. In this work, antibacterial characteristic of hydrogels was mainly investigated towards Escherichia coli ( E. coli ) as a serious disease-leading bacterium. All tested hydrogels have clearly presented good antibacterial activity as CMCh content increases in the hydrogels. Content Type Journal Article Pages 1-12 DOI 10.1007/s10570-012-9658-8 Authors Riham R. Mohamed, Faculty of Science, Cairo University, Giza, Egypt Rania S. Seoudi, Faculty of Science, Cairo University, Giza, Egypt Magdy. W. Sabaa, Faculty of Science, Cairo University, Giza, Egypt Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Co-mixtures of chitosan (CS) and cellulose acetate (CA) were electrospun into fibrous webs from a binary co-solvent containing 70:30 trifluoroacetic acid (TFA): methylene chloride (DCM). Fibrous webs were produced from CS/CA in ratios (wt%) of 20:80, 40:60, 50:50 and 60:40. As determined by SEM analysis, 12% polymer solutions of CS/CA 60:40 produced structures with uniform bead free fibre morphologies with an average fibre diameter of 458 nm. FTIR-spectroscopy confirmed the presence of CS in the as-spun fibres in the form of chitosan-amine trifluoroacetate salts (NH 3 + CF 3 COO − ). Uniform mixing of the CS and CA components was confirmed by DSC analyses. Alkaline neutralisation of the chitosan amine salts was explored as a means of increasing wet stability. The as-spun fibres were found to be relatively unstable in aqueous medium due to the solubility of the chitosan amine salts. Alkaline post-neutralisation was evaluated as means of minimising weight loss and maximising retention of fibrous structure. Content Type Journal Article Pages 1-11 DOI 10.1007/s10570-012-9666-8 Authors George Salihu, Nonwovens Research Group, Centre for Technical Textiles, University of Leeds, Leeds, UK Parikshit Goswami, Nonwovens Research Group, Centre for Technical Textiles, University of Leeds, Leeds, UK Stephen Russell, Nonwovens Research Group, Centre for Technical Textiles, University of Leeds, Leeds, UK Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    The creep behavior of nanocellulose films and aerogels are studied in a dynamic moisture environment, which is crucial to their performance in packaging applications. For these materials, the creep rate under cyclic humidity conditions exceeds any constant humidity creep rate within the cycling range, a phenomenon known as mechanosorptive creep. By varying the sample thickness and relative humidity ramp rate, it is shown that mechanosorptive creep is not significantly affected by the through-thickness moisture gradient. It is also shown that cellulose nanofibril aerogels with high porosity display the same accelerated creep as films. Microstructures larger than the fibril diameter thus appear to be of secondary importance to mechanosorptive creep in nanocellulose materials, suggesting that the governing mechanism is found between molecular scales and the length-scales of the fibril diameter. Content Type Journal Article Pages 1-11 DOI 10.1007/s10570-012-9665-9 Authors Stefan B. Lindström, Mechanics, Department of Management and Engineering, The Institute of Technology, Linköping University, 581 83 Linköping, Sweden Erdem Karabulut, Department of Fiber and Polymer Technology, KTH Royal Institute of Technology, Teknikringen 56–58, 100 44 Stockholm, Sweden Artem Kulachenko, Department of Solid Mechanics, KTH Royal Institute of Technology, Osquars backe 1, 100 44 Stockholm, Sweden Houssine Sehaqui, Department of Fiber and Polymer Technology, KTH Royal Institute of Technology, Teknikringen 56–58, 100 44 Stockholm, Sweden Lars Wågberg, Department of Fiber and Polymer Technology, KTH Royal Institute of Technology, Teknikringen 56–58, 100 44 Stockholm, Sweden Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239

Description:    Alkaline solutions of cellulose and polyethylene-co-acrylic acid (PE-co-AA) were mixed in order to prepare homogeneous cellulose/PE-co-AA blends. Different mixing methods were tested and the evolution of solutions was characterized by rheological methods and optical microscopy. In addition to the solution stage studies, the precipitated dry blends were characterized by Differential Scanning Calorimetry, Scanning Electron Microscopy, Fourier Transform Infrared and Dynamic Mechanical Analysis. Mixing the solutions led to the formation of a suspension, consisting of PE-co-AA particles dispersed evenly throughout the cellulose solution. Based on the conducted studies, it became clear that a uniform quality and the best mixing were attained with a method in which the suspension was frozen and melted between the mixing. In dry blends the polymers were found to be mixed on 1 μm scale, and the crystallization temperature of the PE-co-AA phase was increased ~6 °C due to the nucleation ability of the cellulose phase. Content Type Journal Article Pages 1-9 DOI 10.1007/s10570-012-9668-6 Authors Eve Saarikoski, School of Chemical Technology, Polymer Technology, Aalto University, P.O. Box 16100, 02015 Aalto, Finland Sami Lipponen, School of Chemical Technology, Polymer Technology, Aalto University, P.O. Box 16100, 02015 Aalto, Finland Marja Rissanen, Department of Material Science, Tampere University of Technology, Fibre Materials, P.O. Box 589, 33101 Tampere, Finland Jukka Seppälä, School of Chemical Technology, Polymer Technology, Aalto University, P.O. Box 16100, 02015 Aalto, Finland Journal Cellulose Online ISSN 1572-882X Print ISSN 0969-0239