ALBERT

Description: 〈p〉Publication date: 5 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 562〈/p〉 〈p〉Author(s): Parisa Moazzam, Giorgio Luciano, Amir Razmjou, Ehsan Akbari, Pavel G. Ul’yanov, Soumitro Mahanty〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The degree of available energy on a surface determines how a surface interacts with its surrounding environment such as corrosion. Current approaches to protection of Aluminum surfaces from corrosion mainly focus on adding an organic or inorganic layer to either act as a barrier from oxidant or scarifying to inhibit the corrosion. Altering the surface energy of Al on a molecular level is another alternative approach to efficiently modify the Al surface without the need for another thick expensive protective or scarifying materials. Herein, an attempt was made to understand how a molecular scale energy alteration improves the anticorrosion behavior of an aluminum surface. Two different surface engineering alteration strategies have been discussed; termed ALOSH and ALTSH modification. A variety of analytical instruments, i.e., FTIR, EDAX, XPS, SEM, AFM, WCA, and SFE measurement were used to systematically characterize the samples. Electrochemical impedance spectroscopy revealed that there are different resistances after the surface modifications. The trapping air resistance appeared in ALTSH is approximately 2.4 and 36 times higher than that of ALOSH and bare samples, respectively. The potentiostat analysis results showed that the mili inch per year value of coating for ALTSH was 0.012 while that of ALOSH was 0.507. It was also found that the low surface energy alteration without using inert molecules is not enough to render corrosion inhibition property, as it needs to have a protective energy barrier with no or minimal active electrochemical behavior.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311294-ga1.jpg" width="320" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 561〈/p〉 〈p〉Author(s): Corina L. Reichert, Hanna Salminen, Gabriela Badolato Bönisch, Christian Schäfer, Jochen Weiss〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The concentration ratio of binary surfactant systems can alter the interfacial layer properties, and consequently affect emulsion stability. To study the effect of varying concentration ratios (〈em〉r,〈/em〉 % w/w) of interfaces containing 〈em〉Quillaja〈/em〉 saponins and other naturally occurring food-grade surfactants on their emulsifying properties, we evaluated particle size, ζ-potential, and appearance of 10% oil-in-water emulsions (pH 7) stabilized by 〈em〉Quillaja〈/em〉 saponin - protein or 〈em〉Quillaja〈/em〉 saponin - lecithin mixtures. 〈em〉Quillaja〈/em〉 saponin - Na-caseinate mixtures (〈em〉r〈/em〉 = 0.3:0.2, 0.2:0.3, and 0.1:0.4) formed small emulsion droplets (d〈sub〉43〈/sub〉: 0.2 – 0.3 μm), whereas at 〈em〉r〈/em〉 = 0.4:0.1, the emulsions contained micron-sized droplets (d〈sub〉43〈/sub〉: 1.217 ± 0.558 μm). Emulsions formed by 〈em〉Quillaja〈/em〉 saponin - pea protein mixtures flocculated at 〈em〉r〈/em〉 = 0.3:2.0, 0.2:3.0, and 0.1:4.0. In contrast, 〈em〉Quillaja〈/em〉 saponin - rapeseed lecithin or egg lecithin mixtures were able to generate small emulsion droplets (d〈sub〉43〈/sub〉: 0.2 – 0.5 μm) at all tested concentration ratios. The formation of stable emulsions using binary mixtures of naturally occurring emulsifiers was more dependent on the concentration ratio of the proteins than lecithins, indicating that the interfacial behavior of 〈em〉Quillaja〈/em〉 saponins is more sensitive to the presence of proteins. This was attributed to attractive molecular interactions yielding complexes at interfaces and/or in the continuous phase. This study shows that food-grade binary surfactant mixtures can be used to form stable emulsions with properties being tunable by altering the mixing ratios between surfactants.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571831522X-ga1.jpg" width="429" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 561〈/p〉 〈p〉Author(s): Li Wang, Jingyi Wang, Chi He, Wei Lyu, Wenlong Zhang, Wei Yan, Liu Yang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To improve the biochar’s adsorption performance towards phosphate as well as to endow the biochar with magnetic property, novel rare earth element doped magnetic biochars, Ce/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-BC and La/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-BC, were prepared by separately co-precipitating cerium (Ce) and lanthanum (La) with FeCl〈sub〉3〈/sub〉, FeCl〈sub〉2〈/sub〉 and biochar. For comparison, Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-BC without doping Ce or La was also synthesized. The characterization results indicated that Ce and La ions were successfully doped into the magnetite. The La/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-BC had higher magnetic saturation and point of zero charge than Ce/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-BC. A series of batch experiment results demonstrated that the phosphate adsorption capacity of biochar has been greatly improved after Ce or La doping, especially La. The phosphate adsorption capacity of La/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-BC was 20.5 mg/g at pH 6.5, which was 1.6 and 2.9 times than that of Ce/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-BC and Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-BC, respectively. The adsorption kinetics and isotherms of phosphate onto La/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-BC and Ce/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-BC were best fitted by the pseudo-second order and Freundich model, respectively, indicating that the adsorption process was a multilayer process and controlled by chemical reaction. The combined results of batch experiments and physiochemical analyses revealed that the possible mechanisms were the formation of inner-sphere complex at neutral conditions and electrostatic attraction between positively charged adsorption sites and phosphate under acid conditions. The enhanced phosphate adsorption performance and endowed magnetic property indicated La/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-BC could be used as a promising adsorbent in phosphate removal.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718312615-ga1.jpg" width="455" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Rahul Saha, Ramgopal V.S Uppaluri, Pankaj Tiwari〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Experimental investigations targeting optimum chemical slug formulations for tertiary enhance oil recovery of heavy crude oil in carbonate reservoir were carried out. Based on interfacial tension (IFT), emulsification, wettability alteration and core flooding studies, two alkalis and eight surfactants have been screened by considering conditions similar to oil reservoirs (0–20% salinity and 30–80 °C temperature). Dynamic IFT studies interestingly affirmed oil-layer break time phenomena and hence enhanced emulsification extent. Alkali, thermally stable surfactant mixture and alkali-surfactant mixture systems reduced IFT to 10〈sup〉−1〈/sup〉, 10〈sup〉−2〈/sup〉 and 10〈sup〉−3〈/sup〉 mN/m respectively. Flooding studied confirmed an additional oil recovery of 12.79% and 14.46% for alkali and alkali-surfactant mixture systems respectively. On the other hand, due to optimal emulsion stability, maximal residual oil recovery of 24.58% being achieved for a slug formulation of 0.1 wt% surfactant mixture. Surfactant concentration above 0.1 wt% enabled stronger emulsion formation that detriments displacement efficiency and oil recovery factor.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311178-ga1.jpg" width="341" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Mi Zhang, Jilai Gong, Guangming Zeng, Peng Zhang, Biao Song, Weicheng Cao, Hongyu Liu, Shuangyan Huan〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As a photocatalyst, bismuth vanadate coupled with reduced oxide graphene (BiVO〈sub〉4〈/sub〉-rGO) has been reported for dye degradation. However, this catalyst faced the disadvantages of low catalytic efficiency and long catalytic time. In this paper, BiVO〈sub〉4〈/sub〉-rGO composites were synthesized by a modified hydrothermal method, and characterization results showed the monoclinic BiVO〈sub〉4〈/sub〉 surface successfully coupled with a layer of rGO. The dye removal performance of BiVO〈sub〉4〈/sub〉-rGO composites were evaluated by the degradation of malachite green and rhodamine B under visible light irradiation and photocatalytic results showed that the BiVO〈sub〉4〈/sub〉 with rGO modification could effectively enhance the dyes removal performance. In a specific photocatalytic experiment, BiVO〈sub〉4〈/sub〉-rGO-300 could remove 99.5% MG in two hours and 99.84% RhB in four hours, which was superior to previous studies. Furthermore, application of catalyst in practical wastewater was also taken into account. MG and RhB were degraded by BiVO〈sub〉4〈/sub〉-rGO in several kinds of actual wastewater and experimental results showed that this catalyst could efficiently remove dye in actual environment. This improvement could be ascribed to the increase of special surface area, efficient charge transfer and reduction of electron-hole pair recombination with the incorporation of rGO. The influences of pH, supporting electrolyte and mechanism of the dye degradation were also investigated in details.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉The dyes removal performance for MG and RhB was effectively enhanced and the catalyst has a good potential in dye wastewater treatment.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571831135X-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Min Jae Shin, Young Jae Shin, Jae Sup Shin〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, the molecular imprinting technique and self-assembled monolayer technique were combined to increase the recognition ability of cholesterol. A self-assembled monolayer with 4-mercaptophenol and benzenethiol was formed on a gold plate, and the reaction of cholesteryl chloroformate with the phenol group in the 4-mercaptophenol was followed. This layer was then coated with poly(methyl methacrylate) (PMMA). In order to expose the cholesterol buried under the coating, the partial upper part of the coated PMMA was then removed by stroking the coated plate in acetone solvent. The molecular imprinted site was prepared by hydrolysis of the carbonate bond and extraction of the hydrolyzed cholesterol. This gold plate was used as a working electrode to test the recognition ability for cholesterol. The result showed that the plate obtained good recognition ability for cholesterol compared with cholic acid. The ratio of 4-mercaptophenol to benzenethiol was a very important factor in the ability to recognize cholesterol. Regulating the thickness of the coated PMMA was also one of the important factors to increase the ability to recognize cholesterol.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571831238X-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Nichaphat Thongsai, Nattapong Tanawannapong, Janjira Praneerad, Sumana Kladsomboon, Panichakorn Jaiyong, Peerasak Paoprasert〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Rice husk, an agricultural waste that currently finds few uses, is rich in cellulose-based materials and silica. In this work, a simple one-pot method for preparing carbon dots and mesoporous silica from rice husk was developed, using hydrothermal and calcination methods. The carbon dots exhibited blue emission with excellent photostability, and had a diameter of 4–5 nm and a quantum yield of 3%. They were demonstrated to be capable of detecting alcohol vapors at room temperature, and of distinguishing between methanol, ethanol, and several volatile organic compounds when used as the sensing layer in an optical electronic nose system. The alcohol content of a commercial beverage was successfully determined using the carbon dot-integrated electronic nose. The solvation effect of the alcohol vapors on the electronic absorption spectra of model carbon dot structures was illustrated using time-dependent density functional theory with the dielectric polarizable continuum model. The UV–vis and computational results confirmed that the sensing mechanism of carbon dots is through the modulation of their optical absorbance governed by polar-polar interfacial interactions. This was experimental and computational demonstration of carbon dot sensing of vapors. Their excellent biocompatibility suggests biomedical applications, in addition to sensing. The production of two functional materials from a single low-value waste source was demonstrated.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718312378-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Chenhao Zhao, Zhibiao Hu, Jiangshui Luo〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Porous carbon box or nanoplate has been prepared by synchronous carbonization/activation of potassium citrate, and the corresponding porous carbon nanoplate/Se composite can be obtained using a melting-diffusion method. The influence of structure parameters including specific surface area and porous structure of porous carbon and resultant carbon/Se composite on electrochemical properties are studied. It is found a moderate micropore size of carbon substrate and low specific surface area of carbon/Se composite are benefit to electrochemical performances. At an optimal temperature of 700 °C, the porous carbon composed of micro- and small meso-porous (2–4 nm) structure has a BET specific surface area of 695.4 m〈sup〉2〈/sup〉 g〈sup〉−1〈/sup〉, and the amorphous Se is uniformly encapsulated into its porous structure. As the cathode material of Li ion battery, the porous carbon nanoplate/Se composite delivers an initial discharge capacity of 589.2 mAh g〈sup〉−1〈/sup〉 with Coulombic efficiency of 72.6% at 0.2C, and capacity retention of 78.3% can be obtained after 500 cycles at 2C. Even at a high rate of 4C, a discharge capacity of 415.2 mAh g〈sup〉−1〈/sup〉 can be reached.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718312950-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Ting Zou, You Han, Xinxue Li, Wei Li, Jinli Zhang, Yan Fu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Controlled synthesis of noble metal nanocatalysts with desirable catalytic activities remains a great challenge. Inspired by electron-rich functional groups and supramolecular assembly properties of natural nucleotides, herein we propose a versatile approach to construct Pd nanocatalysts through employing seven nucleotides as both electron donors and stabilizers. The catalytic performance of nucleotide-Pd complexes are greatly associated with the chemical structures of nucleobases as well as the number of phosphate groups. Guanosine 5′-triphosphate-Pd complexes possess high activities in the hydrogenation reduction of 4-nitrophenol assisted by NaBH〈sub〉4〈/sub〉, with the relative rate constant of 7770 min〈sup〉−1〈/sup〉 mM〈sup〉−1〈/sup〉 at 25 °C. Pd(II)-coordinated nucleotides are also promising in NaBH〈sub〉4〈/sub〉-mediated degradation of organic dyes. This work demonstrates a green and facile process to construct Pd nanocatalysts containing abundant active sites under the assistance by natural nucleotides.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718314377-ga1.jpg" width="471" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Mirela Teodorescu, Maria Bercea, Simona Morariu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The present study has been focused on investigation of some polymer mixtures of interest for biomedical applications. Three pairs of polymers, namely: poly(vinyl alcohol) (PVA)/poly(vinylpyrrolidone) (PVP), PVA/hydroxypropyl cellulose (HPC), Pluronic F127 (PL)/HPC were subjected to viscometic study in dilute solution. The intrinsic viscosity, the Huggins constant and 〈em〉B〈/em〉 parameter, as well as the miscibility parameters were discussed. The hydrodynamic properties of these polymer mixtures were analyzed as compared with the corresponding single polymer solutions at two reference temperatures, 〈em〉i.e.〈/em〉 the storage (25 °C) and physiological (37 °C) temperature. Each mixture has shown distinct behavior: PVA/PVP system is fully miscible regardless composition or temperature; the miscibility of PVA/HPC or PL/HPC mixtures is influenced in a specific manner by the ratio between the two polymers and by the temperature. The main interest is a better understanding of the polymer-polymer interactions and to identify the synergistic behavior in order to design multicomponent biomaterials with targeted properties. The compatibility of these polymers was attributed to the favorable hydrogen-bonding interactions between the hydroxyl groups of PVA and carbonyl groups of PVP, hydroxyl groups of PVA and HPC, and ether groups of PL and hydroxyl groups of HPC. On the other hand, hydrophobic interactions influence the polymer/polymer miscibility.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311749-ga1.jpg" width="225" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Xiaopeng Xue, Zhonghao Xu, Israel Pedruzzi, Ping Li, Jianguo Yu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Interface phenomena between low molecular weight (LMW) carboxylic acids and muscovite was investigated through molecular dynamic simulation and experiment, where the typical monocarboxylic acids including formic acid (C〈sub〉1〈/sub〉), acetic acid (C〈sub〉2〈/sub〉), propionic acid (C〈sub〉3〈/sub〉) and butyric acid (C〈sub〉4〈/sub〉) were used as models. Density distribution, adsorption energy, root mean square dynamic (RMSD) of carboxylic acids on water-muscovite interface were calculated through molecular dynamic simulation, and the advanced characterization methods, such as ATR-FTIR spectra, AFM images and contact angle were performed to test and verify the relative simulation findings. The molecular simulation showed that carboxylic acids adsorbed on surface of muscovite through hydrogen bond between H atom of 〈img src="https://sdfestaticassets-us-east-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉COOH functional group of carboxylic acid and O atom of muscovite, belong to outer sphere adsorption, and ATR-FTIR spectra and AFM images confirmed this finding. Adsorption energy for long carbon chain carboxylic acid (C〈sub〉4〈/sub〉) was higher than that for short carbon chain carboxylic acid (C〈sub〉1〈/sub〉, C〈sub〉2〈/sub〉 and C〈sub〉3〈/sub〉) due to the effect of carboxylic acid diffusion on water-muscovite interface. The hydrophilic functional group 〈img src="https://sdfestaticassets-us-east-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉COOH of carboxylic acids preferably adsorbed on muscovite surface, while the hydrophobic functional groups 〈img src="https://sdfestaticassets-us-east-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉CH〈sub〉3〈/sub〉 and 〈img src="https://sdfestaticassets-us-east-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉CH〈sub〉2〈/sub〉 of carboxylic acids were far from the muscovite surface. So, the hydrophobicity on muscovite surface increased due to the adsorption of carboxylic acids, which resulted in the increase of contact angle of water on muscovite surface.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718310823-ga1.jpg" width="242" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Guowen Chen, Yuying Fu, Fuge Niu, Hao Zhang, Xiaomeng Li, Xin Li〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To evaluate the performance of biopolymer fabricated nanoparticle under commercial processing conditions, the stability of gum Arabic (GA)-zein-cur (curcumin) colloidal system was recorded and analyzed. The results showed that GA-zein-cur system is colloidal stable in the pH range of 5–8, however, encapsulated curcumin degraded rapidly as long as the pH changes. As for processing temperature, more than 70 °C will affect the spatial structure of zein and leading to the leak or exposure of encapsulated curcumin which result in the degradation of curcumin. Na〈sup〉+〈/sup〉 has no significant effect on colloidal and chemical performance of nanoparticles while Fe〈sup〉3+〈/sup〉 could penetrate the zein nanosphere and compromise curcumin. Results of our work imply that the protein-based core-shell delivery system has advantages in solubilizing the hydrophobic compounds and has certain ability to protect the encapsulated material against the unfavorable environment.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718308707-ga1.jpg" width="313" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Haiqin Wu, Liang Yan, Liyang Fu, Lan Jin〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The interaction of alizarin with aminophenylboronic acid (ARS-PBA) was used through a new strategy for electrochemical sensors of glucose. In the present work, ARS-PBA complex and the layered double hydroxide nanosheets (LDH nanosheets) were successfully assembled on indium tin oxide (ITO) electrodes via layer by layer technology method. The resulted electrode was characterized by UV–vis, X-ray diffraction (XRD), atomic force microscope (AFM) and scanning electron microscope (SEM) to achieve the morphological, structural and compositional information. Cyclic voltammetry and differential pulse voltammetry were conducted to investigate electrochemical properties of the modified electrode. Moreover, the modified electrode was used as a non-enzymatic sensor for glucose determination, exhibiting good electrochemical properties, fast response time and long-term stability. At the optimum conditions, the constructed electrode sensor shows a linear range of 0∼1.00 μmol/L and a low detection limit of 4.0 nmol/L (S/N = 3) for glucose. On the basis of affinity between glucose and ARS-PBA complex, the functionalized electrode showed a high selectivity toward glucose over other concomitant biomolecues (dopamine, uric acid and ascorbic acid). Therefore, a simple and effective electrochemical method was developed and offers a complementary tool for the detection of glucose.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718313219-ga1.jpg" width="358" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Priyadharsan A., Shanavas S., Vasanthakumar V., Balamuralikrishnan B., Anbarasan P.M.〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The sunlight driven photocatalytic activity of semiconductor based nanocomposites has attracted extensive attention in recent years for environmental remediation and energy applications. Here, we report an effective strategy to synthesis ternary MoS〈sub〉2〈/sub〉-ZnO-reduced graphene oxide (MZG) nanocomposite as a photocatalyst by a facile hydrothermal method. The prepared nanoparticles were characterized by various analytical tools. The basic photocatalytic mechanism of the composite material was exhibited the photoexcited electrons of ZnO can be readily transported to MoS〈sub〉2〈/sub〉 through rGO backbone, reducing the electron-hole pair recombination. The photocatalytic performance was optimized using methylene blue as a model organic dye under natural sunlight irradiation. The results were compared with pure and binary, MZG ternary nanocomposites exhibit superior photocatalytic activity. In a continuation of environmental remediation studies, MZG ternary nanocomposites revealed high antibacterial activity towards 〈em〉Escherichia coli (E.coli)〈/em〉 and 〈em〉Staphylococcus aureus (S.aureus)〈/em〉, highlighting its potential photocatalytic and antibacterial properties at different industrial and medical applications. This study may afford some inspiration for the rational design and facile synthesis of composite catalysts with a high and tunable catalytic property through a green, efficient pathway.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718310835-ga1.jpg" width="233" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Anusha Chandra, Bhuvanesh E, Sujay Chattopadhyay〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Permselectivity and water uptake behaviors of anion exchange membrane (AEM) were investigated with organic acids. Contribution of the number of carboxyl group (acetic acid: AA, malic acid: MA, citric acid: CA) and hydrocarbon chain lengths (formic acid: FA, AA, propionic acid: PA and n-butyric acid: BA) in water uptake and permselectivity values were separately investigated with five different concentrations 0.025, 0.05, 0.075, 0.1 and 0.125 mol·L〈sup〉−1〈/sup〉 of each acid at two different pH 2.0 and 7.5 conditions. Microstructural changes occurring due to interaction of carboxylate anion and NR〈sub〉4〈/sub〉〈sup〉+〈/sup〉 groups of AEM resulted in permselectivity behavior. Permselectivity trend: CA 〈 MA 〈 AA could be explained by counter-ion condensation resulting out of strong counter-ion interactions with AEM fixed charges. Co-ion mobility values could explain variation in permselectivity at pH 2.0 and 7.5. While, water uptake and ionic size were dominant factors to explain the permselectivity trend: FA 〉 AA 〉 PA 〉 BA. Complex nature of interactions due to properties (size, charge, ionic charge density, mobility, diffusivity, stokes radius etc.) of carboxylate anions were explained using diffusivity ratio (counter/co-ion, 〈em〉D〈sub〉2〈/sub〉/D〈sub〉1〈/sub〉〈/em〉), adsorption equilibrium and fraction of dissociated species.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718313906-ga1.jpg" width="276" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Svetlana Fedorenko, Alexey Stepanov, Rustem Zairov, Ondrej Kaman, Rustem Amirov, Irek Nizameev, Kirill Kholin, Ildus Ismaev, Alexandra Voloshina, Anastasiya Sapunova, Marsil Kadirov, Asiya Mustafina〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The present work introduces one-pot synthetic route to join ultra-small iron oxides (6 nm) with Gd(III) complexes in small (∼30 nm) silica nanoparticles with high longitudinal and transverse relaxivity values (r〈sub〉1〈/sub〉 = 34.7 mM〈sup〉−1〈/sup〉 s〈sup〉−1〈/sup〉 and r〈sub〉2〈/sub〉 = 64.7 mM〈sup〉−1〈/sup〉 s〈sup〉−1〈/sup〉 at 0.47 T). The design of the nanoparticles is based on the core-shell morphology, where the Gd(III) complexes were doped into the exterior silica layer. The doping mode is the reason for an efficient interfacial hydration and the small suppressing of r〈sub〉1〈/sub〉 by iron oxides. The measurements on the whole body scanner at 1.5 T confirm the high contrasting abilities of T〈sub〉1〈/sub〉 (Gd) and T〈sub〉2〈/sub〉 (iron oxide) components in the nanoparticles. Poor aggregation behavior of the nanoparticles in water is due to high electrokinetic potential value (−78 mV). Greater aggregation of the nanoparticles in the buffer solutions of bovine serum albumin enhances the disturbing effect of iron oxides on the longitudinal relaxation and facilitates the transverse relaxation. The higher surface activity of the nanoparticles results in their greater cytotoxicity versus the silica coated iron oxides, although the cytotoxicity is low in the concentration range which is within the region of interest for MRI technique.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311166-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Jiwei Lu, Mingjun Sun, Zhitao Yuan, Shengliang Qi, Zhongyun Tong, Lixia Li, Qingyou Meng〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Serpentine, as a common magnesium silicate mineral found in many ores around the world, is usually dispersed/depressed with the dispersants/depressants by adsorbing on the surface of serpentine. Therefore, in this work, the interaction mechanism of the dispersant of sodium hexametaphosphate (SHMP) was investigated in detail though solution chemistry calculations, Fourier transform infrared spectroscopy (FTIR) analyses, zeta potential measurements, adsorption and ion release tests, and molecular dynamics (MD) simulations. Results indicated that anionic components of H〈sub〉2〈/sub〉PO〈sup〉−〈/sup〉〈sub〉4〈/sub〉 and HPO〈sup〉2−〈/sup〉〈sub〉4〈/sub〉 in SHMP, as the predominant and effective species, adsorbed on the Mg and Si sites of the serpentine surfaces, which occurred on the Si site through the electrostatic interaction and on the Mg site through the chemical adsorption. As a result, the surface charge of serpentine was reversed from positive to negative at all pH region examined. In addition, ion release tests confirmed that SHMP dissolved some Mg ions for forming soluble complexes from the serpentine surface into the solution. Thus, the negative charge of it was further enhanced, which would lead to much stronger repulsion between negatively charge valuable minerals (e.g., pentlandite) and serpentine. Thus, the serpentine would be well dispersed with the valuable minerals.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718312329-ga1.jpg" width="398" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Konstantin Popov, Maxim Oshchepkov, Elena Afanas’eva, Elena Koltinova, Yulia Dikareva, Hannu Rönkkömäki〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Scaling in reverse osmosis facilities, boilers, heat exchangers, evaporation plants, and oilfield applications is a serious problem worldwide. A widely used solution for controlling scale deposition is an application of chemical inhibitors. However, irrespective of the broad and a long-term antiscalant application, the mechanisms of scale inhibition are still the matter of discussions.〈/p〉 〈p〉In order to provide a new insight into the mechanism of the scale inhibition, a novel dynamic light scattering (DLS) special technique is used to study the bulk supersaturated gypsum aqueous solutions during the induction period. It is based on the standard Ag nanoparticles (ARGOVIT) injection into the supersaturated gypsum solution. These nanoparticles act as an internal indifferent light scattering intensity reference, and provide a semiquantitative measurement of a relative gypsum particles content in a blank solution and in the system treated with phosphonates: amino-tris(methylenephosphonic acid), ATMP; 1-hydroxyethane-1,1-bis(phosphonic acid), HEDP; 2-phosphonobutane-1,2,4-tricarboxylic acid, PBTC. It is found that ATMP sufficiently reduces the number of gypsum nuclei, spontaneously formed in the supersaturated solutions. The less effective inhibitors of gypsum scaling HEDP and PBTC also reduce the gypsum nuclei number, but to a less extent. A tentative nonconventional mechanism of scale inhibition in the bulk supersaturated aqueous solutions of gypsum is proposed.〈/p〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718307192-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Hong-Liu Jiang, Jie-Ci Lin, Wei Hai, Hong-Wei Tan, Yu-Wei Luo, Xiao-Lin Xie, Yao Cao, Fu-An He〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, a novel crosslinked porous β-cyclodextrin-based polymer containing carboxylic acid groups (CT-β-CD) was synthesized successfully and characterized by SEM, FTIR, 〈sup〉13〈/sup〉C solid-state NMR, water-contact-angle measurement, and TGA. The resultant CT-β-CD with triple absorption effects including inclusion complextion, porous network capture, and electrostatic interaction was employed as an adsorbent for removing methylene blue dye from aqueous solution, which exhibited several advantages such as high absorption capacity (q〈sub〉max〈/sub〉 = 672 mg/g), rapid absorption rate, good recyclable ability, and selective adsorption for cationic dyes. The influences of initial MB concentration, absorption time, and pH value on the absorption behavior of CT-β-CD for MB were also investigated. In addition, it was found that the pseudo-second-order kinetic and the Langmuir model for adsorption isotherm could be used to describe the MB absorption behavior of CT-β-CD.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718313050-ga1.jpg" width="437" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Qing Fan, Dali Zhou, Lei Yang, Jiabei Zhou, Shuang Yang, Yongqiang Yang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Glass lubricants have great potential in industrial metal forming processes such as hot extrusion of titanium and titanium alloys. In this work, based on the extrusion process of commercial-purity titanium (TA2) at 800 °C, glass lubricants with low melting points are designed. The thermal properties, high-temperature oxidation resistance and friction properties of uncoated and glass-coated TA2 samples are systemically studied, which reveals the good lubricating and anti-oxidation properties of the samples. The glass lubricant melts into a viscoelastic film at 800 °C to insulate TA2 from oxygen and reduce friction, and automatically peel off during cooling due to the significantly mismatched thermal expansion between the glass coating and TA2 substrate. This work provides a guidance for designing glass-based lubricants used in hot extrusion of metals.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571831152X-ga1.jpg" width="322" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): T. Rijnaarts, J. Moreno, M. Saakes, W.M. de Vos, K. Nijmeijer〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Reverse electrodialysis (RED) is a process to harvest renewable energy from salinity gradients. Under lab conditions with artificial salt solutions, promising results have been achieved in recent years. However, in large scale industrial applications, natural waters are used and that poses challenges such as fouling. Fouling of anion exchange membranes (AEMs) by organic matter (e.g. humic acids) has been identified as a possible cause that lowers RED performance with natural waters. In this work, natural river and seawater at the Afsluitdijk (The Netherlands) are used to study the RED performance of six different AEMs. These AEMs are characterized before and after RED experiments with natural waters. The effect of natural fouling is found to be specific for each AEM and highly dependent on their respective chemistries and associated membrane properties. Firstly, aromatic AEMs with a low swelling degree showed a permselectivity decrease as well as membrane resistance increase. Secondly, aliphatic AEMs with a medium swelling degree experienced only a membrane resistance increase. Finally, only a decrease in permselectivity was observed for aliphatic AEMs with large swelling degrees. Subsequently, the effect of AEM fouling is compared to the observed decrease in RED performance and this shows that AEM fouling can only explain a minor part of the losses in open circuit voltage (OCV). The RED power densities dropped by 15–20% over 12 days, independent of the AEMs selected, while the reduced AEM performance could only explain 2–4% of this reduction in power density. This demonstrates that next to AEM fouling, also other factors, such as spacer fouling, are expected to be the dominant fouling mechanism, reducing the performance to a much larger extent.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718313505-ga1.jpg" width="481" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Yibo Ouyang, Jin Zhao, Ri Qiu, Shugang Hu, Yan Zhang, Peng Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Bioinspired superhydrophobic and oil-infused surfaces have been recognized as interesting and promising materials for a wide range of applications correlated with water environment, such as corrosion and biofouling inhibition. Which material is the better choice still waits to reveal. In this study, taking stainless steel as the substrate, superhydrophobic and oil-infused surface based on Cu(OH)〈sub〉2〈/sub〉 matrix with prickly chestnut husk morphology is respectively obtained via successive steps. During the preparation of superhydrophobic surface, firstly, discrete Cu particles are electrodeposited onto stainless steel. After that, oxidation of the as-deposited Cu particles leads to the prickly Cu(OH)〈sub〉2〈/sub〉 following a dissolution-crystallization mechanism. Under a mild condition, dodecanethiol vapor modifies prickly matrix to achieve superhydrophobicity by anchoring the long-chain organic moiety onto Cu(OH)〈sub〉2〈/sub〉 surface. Since superhydrophobic matrix is intrinsically superoleophilic, oil-infused surface is finally constructed onto stainless steel. Taking typical marine fouling organisms including sulfate-reducing bacteria (SRB) and diatoms as the representatives, oil-infused surface can steadily prevent the biofouling on stainless steel, showing the better performance than superhydrophobic surface for biofouling inhibition. Using epoxy resin as the artificial fouling agent, the pulling force to remove the glued solid on oil infused surface is much lower than that on bare stainless steel, illustrating oil layer acting as the separation cushion between fouling agent and underneath substrate.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Superhydrophobic and oil-infused surface based on prickly chestnut husk morphology Cu(OH)〈sub〉2〈/sub〉 are used as the representatives to illustrate which is the better choice to prevent marine biofouling.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718307477-ga1.jpg" width="295" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Chengyi Wang, Lin Chen, Shanshan Liu, Liang Zhu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, nitrite desorption from activated carbon fiber (ACF) in capacitive deionization (CDI) and membrane capacitive deionization (MCDI) was examined and the effects of the operation parameters (pH, voltage, temperature and flow rate) and co-existing matters were deeply investigated. Desorption mechanisms were analyzed via Brunauer–Emmett–Teller (BET) and Fourier transform infrared spectroscopy (FTIR). Results showed that the final desorption ratio increased from 0 to 100% in MCDI and the enhancement was also observed in CDI that the ratio increased from 18.7 to 83.5% when solution pH increased from 2 to 10. Increasing the voltage and solution temperature also contributed to the ion desorption both in CDI and MCDI, while the effect of flow rate was negligible. Generally, MCDI showed greater desorption performance than CDI due to the elimination of co-ions effect. However, it was interesting to find that when the voltage was in the range of 0.4-0.6 V, the desorption ratio increased from 38.4% to 50.8% in MCDI which was lower than that in CDI (45.4% to 55.8%). One possible explanation was that the presence of membranes would inevitably introduce additional resistance into the system and decrease effective voltage especially at lower voltage. Compared to the desorption performance in MCDI when the solution pH was 2, the greater desorption performance was observed in CDI which was mainly attributed to the site competition. As for the influence of coexisting matters, the presence of bovine serum albumin (BSA) posed an adverse effect for the ion desorption both in CDI and MCDI. The inhibition effect was more serious in CDI, and pore blockage caused by BSA attachment onto ACF was the main mechanism. Therefore, this study would provide some referential advice for the investigation of ion desorption in CDI and MCDI.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718312275-ga1.jpg" width="255" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 28 June 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Anwesha Sarkar, Brent S. Murray〈/p〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Anh-Tu Ngo, Salvatore Costanzo, Pierre-Antoine Albouy, Vincent Russier, Sawako Nakamae, Johannes Richardi, Isabelle Lisiecki〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Novel colloidal crystals made of maghemite nanocrystals are fabricated by a co-evaporation method with a mixture of ethanol/hexane. Through a series of comprehensive characterization performed by grazing incidence small-angle X-ray scattering (GISAXS) and field emission gun scanning electron microscope (FEG-SEM), we show the first example of well-defined face-centered cubic (fcc) colloidal crystals. In order to obtain a clear picture of the crystal formation, the amount of ethanol in the solution is monitored using gas chromatography. In parallel, the interactions between the nanocrystals are calculated by statistical mechanics theory using solubility parameters. Theory predicts the formation of colloidal crystals at quite high amounts of ethanol around 15%, in perfect agreement with experimental results. We show that the theory can further be applied to predict the optimal experimental conditions for the formation of colloidal crystals using other solvent mixtures.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571830788X-ga1.jpg" width="446" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Xiaoyu Gao, Gang Wen, Zhiguang Guo〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Based on controlling ZnO nanoarrays morphology and employing fluorine-free modification agent, superhydrophobicity in air and superoleophobicity under water were successfully achieved on the prepared cotton fabric surfaces via a two-step hydrothermal reaction. To increase adhesion between ZnO crystal layer and substrate surface, two kinds of silane coupling agents (hydrophobic TTOP-12 and hydrophilic KH550) were added selectively in the pretreatment process. The as-prepared fabric exhibited great tolerance and durableness towards external harsh environments, such as mechanical abrasion, UV radiation, immersion of acid or alkali, and high temperature. In comparison, superhydrophobic fabrics showed superior separation effect for heavy oil and water mixture, while underwater superoleophobic fabric can also show efficient separation of water and light oil with high separation efficiency and flux. In a word, heavy/light oil and water mixtures can be separated efficiently as need by choosing cotton fabrics with various wettabilities.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉The cotton fabrics with superhydrophobic and superolephobic underwater were fabricated in this paper via controlling ZnO crystal morphology and choosing various modification agents, and the results showed that they possessed efficient separations as need for oil/ water mixtures with both an efficiency and a high flux.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311129-ga1.jpg" width="386" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Zane A. Grady, Alexandria Z. Arthur, Christopher J. Wohl〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Controllable surface morphology is requisite across a gamut of processes, industries, and applications. The surface morphology of silica-coated polystyrene microspheres was controllably modified to enable generation of both smooth and bumpy, or raspberry-like, surfaces. Although smooth and raspberry-like silica shells on polystyrene templates have been demonstrated extensively, the method described here used readily available materials to produce radical changes in surface morphology from a single polystyrene template coated in silica through a facile sol-gel reaction processes. Silica shells were deposited via a sol-gel process (using tetraethyl orthosilicate as the silica precursor) onto 1 to 2 μm diameter anionic polystyrene spheres, fabricated by emulsifier-free polymerization. By varying the concentration of silica precursor and ammonium hydroxide catalyst and altering the electrostatic surface interactions via addition of a cationic polymeric brush, an array of surface topologies was generated. Incremented addition of the ammonium hydroxide base catalyst and sol-gel precursors generated smooth silica shells, whereas identical one-pot reactions led to raspberry-like shells. This modification of sol-gel deposition on large polystyrene cores via means of reactant addition offers additional control over sol-gel shell morphologies.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718313414-ga1.jpg" width="264" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Mahsa Baghban Salehi, Mina Soleimanian, Asefe Mousavi Moghadam〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this paper, the overall performance of a disproportionate permeability reduction mechanism for a sulfonated polyacrylamide copolymer and the chromium triacetate crosslinker was investigated. A home-built gel filtration system was used for visual inspections and evaluations of the hydrogel performance. The experiments were conducted based on rheological test plans, energy-dispersive X-ray spectroscopy, and scanning electron microscope. Accordingly, quadratic equations based on the polymer and crosslinker concentrations were presented predicting the rupture pressure gradient of the hydrogel and the hydrogel output due to the oil and water injection through the hydrogel. It was indicated that the polymer concentration was the main effect on the rupture pressure gradient of the hydrogel and hydrogel output. Moreover, under constant concentration of crosslinker, increasing polymer concentration showed an increase in rupture pressure gradient and output of the hydrogel due to the increase of elastic modulus of hydrogel network and its strength as a viscoelastic material. As the hydrogel structure illustrated no rupture during the gel filtration experiments, a mechanism presented justifying the disproportionate permeability reduction phenomenon which in that under constant condition, the oil permeability through hydrogel was greater than the water permeability.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718312561-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Tanara Sartori, Gabriela Feltre, Paulo Jose do Amaral Sobral, Rosiane Lopes da Cunha, Florencia Cecilia Menegalli〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This work aimed at evaluating the influence of glycerol concentration and storage relative humidity (RH) on gluten-based adhesive properties. Adhesive aging and adhesive application over different food substrates were also evaluated. For such purpose, three adhesive formulations were developed from different gluten:glycerol ratios (1:0.6, 1:1, and 1:1.4), which were applied over a pectin-based film as support material. The adhesives presented better adhesion and cohesion properties when stored at 58% RH. The formulation with the best adhesive properties was the 1:1 gluten:glycerol ratio. The degradation of the adhesives during aging was considered small in the first thirty days. The adhesives presented potential to be applied on food grade materials with low hydrophilicity.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718312032-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Xuemei Zheng, Shiyu Fu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Nanocellulose, a nano blocks extracted from plant biomass, is a potential candidate for fabricating superhydrophobic materials by reconstructing roughness surface and modifying with low-surface-energy chemicals. In this work, a facile spray drying was used to prepare the nanocellulose-based micro-particles with hierarchical surface structure. The surface structure of particles can be regulated by changing the size of nanocellulose. The prepared particles were modified with methyltrimethoxysilane (MTMS) by chemical vapor deposition (CVD), and then the modified particles mixed with polydimethylsiloxane (PDMS) proportionally are formulated a new coating, which can be sprayed on filter papers or glass to obtain superhydrophobic surface. The new finding is that the length of nanofiber had great influence on surface structure of formed particles from spray, and the shorter nano-fiber was easier to derive micro-particles with more compact, more even rough surface structure and better superhydrophobicity of final coated materials compared with the longer nanofiber. The superhydrophobic property of the coating can be controlled simply by changing the cellulose nano-fiber length, which is of great significance on hierarchical structure design of the nanocellulose-based superhydrophobic materials.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718307751-ga1.jpg" width="302" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Erica Pensini, Abdallah Elsayed, Braulio Macias Rodriguez, Alejandro G. Marangoni, Ashutosh Singh, Brent Sleep, Gordon Hayward, Kristine Lamont, Christopher M. Collier〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Trapping and treating Cr(VI) is of great importance to environmental applications. In this work, the natural polymer scleroglucan and the reducing agent sodium thiosulfate were used to produce a water-based polymeric fluid to simultaneously trap and treat Cr(VI) in the subsurface. The thiosulfate reduced toxic Cr(VI) to less toxic Cr(III), as was apparent from fluid discoloration from bright orange to dark brown. Additionally, the viscosity of scleroglucan fluids containing sodium thiosulfate was low before mixing with Cr(VI) (150 mPa·s with 1 wt% scleroglucan in water at 23 °C), suggesting that the fluids can be effectively pumped in the subsurface. As sorption of scleroglucan onto geological substrates can affect its transport in geological media, sorption was measured using a Quartz-Crystal Microbalance with Dissipation Monitoring (QCM-D). Sorption of scleroglucan onto silica (used as a model geological substrate) was promoted in 100 mM CaCl〈sub〉2〈/sub〉 at pH = 7 and in deionised water at pH = 4, whereas it was hindered by humic acids (HA), which are usually naturally present in groundwater. Upon contact with Cr(VI) and sodium thiosulfate, scleroglucan chains crosslinked and the fluids gelled, acquiring high viscosity (approximately 2000 mPa·s) in water, in salt solutions (100 mM KCl or 100 mM CaCl〈sub〉2〈/sub〉) and in the presence of HA. Gelled scleroglucan was also characterized by high shear viscoelastic moduli and became plastic at high compressional loads (70 N to 100 N, depending on the water chemistry). Gelation is due to the crosslinking of scleroglucan by Cr(III), following the reduction of Cr(VI) by sodium thiosulfate. Scleroglucan fluids containing sodium thiosulfate may potentially form a barrier around the Cr(VI) contaminated zone, preventing its migration during treatment.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311373-ga1.jpg" width="309" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Patricio Serafini, Marcos Fernández Leyes, Jhon F. Sánchez M., Romina B. Pereyra, Erica P. Schulz, Guillermo A. Durand, Pablo C. Schulz, Hernán A. Ritacco〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The micellization process of the aqueous mixed system triton X-100 (TX100) – dodecyltrimethylammonium bromide (DTAB) has been studied with a battery of techniques: surface tension, static and dynamic light scattering and ion-selective electrodes. Results have been also analysed with two thermodynamic procedures: the Regular Solution Theory or Rubingh’s model and the recently developed Equation Oriented Mixed Micellization Model (EOMMM). For α〈sub〉DTAB〈/sub〉 ≤ 0.40 (α〈sub〉DTAB〈/sub〉: total molar fraction of the system without considering the water), the micelles are predominantly TX100 with scarce solubilized DTA〈sup〉+〈/sup〉 ions, with TX100 acting as a nearly ideal solvent. In the range 0.50 ≤ α〈sub〉DTAB〈/sub〉 ≤ 0.75, it seems that none of the components acts as a solvent. Above α〈sub〉DTAB〈/sub〉 ≈ 0.75 there are noticeable changes in the size and electrophoretic mobility of the micelles. These phenomena have been interpreted in the light of the thermodynamic results and literature on some TX100-ionic surfactant mixtures. The case under study is an almost ideal but very asymmetric mixed surfactants system, what is very interesting in view of the very different nature and structures of the components.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718310574-ga1.jpg" width="235" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 27 May 2017〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Johanna Milsmann, Kathleen Oehlke, Katrin Schrader, Ralf Greiner, Anja Steffen-Heins〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Edible solid lipid nanoparticles (SLN) stabilized by a mixture of food grade emulsifiers (soy bean lecithin, Tween 20, sucrose stearate) were added to o/w emulsions previously stabilized by anionic SDS, non-ionic Tween 20 or cationic CTAB. The aim of the study was to understand the fate of both SLN and oil droplets in these mixtures focusing on the impact of the surfactant used to stabilize the emulsion. The presence of SLN in emulsions led to increased emulsion stability as reflected by droplet size measurements and accelerated creaming experiments. This could be attributed to an increase in the viscosity of the sample, but also to changed properties of the o/w interface. Zeta potential measurements revealed that the surfactant composition at the o/w interface had changed in SDS and CTAB stabilized but not in Tween 20 stabilized emulsions. SLN remained detectable in the continuous phase of each emulsion system over three weeks of storage but were not detected at the o/w interface of oil droplets. The particle size of the SLN remained unchanged whereas their zeta potential increased in SDS and CTAB stabilized emulsions to a similar magnitude (+/− 68 mV) but opposite signs. The melting temperature and melting enthalpy of SLN decreased in emulsions indicating that part of the lipid matrix was dissolved by oil from the emulsion. Accordingly, a time-dependent transfer of crystalline triglycerides originating from the SLN into the oil phase of separated model emulsion systems was verified.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775717305046-fx1.jpg" width="450" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): S. Nazari, S.Z. Shafaei, B. Shahbazi, S. Chehreh Chelgani〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Recent investigations indicated that using nanobubbles (NBs) in flotation separation of fine particles (〈25 μm) has several advantages; however, a detail study on performances of various flotation parameters (such as hydrodynamic variables and particle properties) and their impacts on recovery of coarse particles (〉100 μm) in the presence of NBs have not been fully understood. This work was explored how NBs can change impacts of Reynolds number, conventional flotation bubbles (CBs), air flow rate and particle sizes on flotation recovery of coarse particles (−425 + 106 μm). Several flotation experiments were carried out by using pure quartz in the presence and absence of NBs. Kendall’s tau (τ) as an accurate statistical method was introduced and applied through the provided dataset from the experiments to assess the impacts of NBs. In the absence of NBs; τ assessments demonstrated that there are negative correlations between particle size, air flow rate, Reynold number and recovery (τ ∼ −0.81, −0.18 and −0.12, respectively), and a positive relationship between CBs and recovery (τ ∼ 0.08). In general, results indicated that recovery of coarse particles was increased by ∼14% (on average) in the presence of NBs; however, the magnitude of relationships was not changed (just correlations between Reynolds and CBs vs. recovery were changed: τ ∼ −0.17 and 0.13, respectively). Assessing the simultaneous impacts of Re and CBs on recovery showed that in the presence of NBs; the highest recovery (on average) may receive in lower Re values and higher CB sizes in comparison with in the absence of NBs. Taking all these interactions into consideration, it can be concluded that increasing the rate of bubble-particle attachment and decreasing the impact of Re can be the main reasons for the enhancement of coarse particle recovery in the presence of NBs.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718307635-ga1.jpg" width="243" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Lev O. Filippov, Inna V. Filippova, Zineb Lafhaj, Daniel Fornasiero〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The adsorption mechanism of collector mixtures and the implication for mineral flotation are discussed in light of the results of a quantitative study of the flotation of fluorapatite and calcite with mixtures of fatty alcohol and oleate collectors. It was found that the recovery of fluorapatite and calcite floated with oleate improved considerably after addition of the fatty alcohol. With oleate alone, the low mineral flotation was attributed to a patchy oleate surface coverage and oleate dimers but with the collector mixture it was shown that the fatty alcohol co-adsorbs with oleate on the mineral surface and in a much larger quantity than when it was used alone. Spectroscopic analyses reveal that the amount of oleate adsorbed remains similar when added alone or in mixtures, which implies that the co-adsorption of the fatty alcohol is responsible for the improved mineral flotation. Replacement of oleate dimers with fatty alcohol-oleate complexes at the mineral surface may also explain the increase mineral hydrophobicity and flotation.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Infrared spectra of fluorapatite (Fap) with fatty alcohol (PX) or oleate (Ol) alone, and with Ol+½PX, Ol + PX or Ol+2PX mixtures at pH 9.0.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718308112-ga1.jpg" width="278" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Xudong Wang, Zhangjun Chen, Ke Li, Xiaodong Wei, Zhenbin Chen, Juan M. Ruso, Zhenghua Tang, Zhen Liu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, titanium dioxide particle was firstly modified with glutaraldehyde, and modification conditions, i.e. particle size (〈em〉d〈/em〉), active temperature (〈em〉T〈sub〉a〈/sub〉〈/em〉), modification temperature (〈em〉T〈sub〉m〈/sub〉〈/em〉), modification time (〈em〉t〈sub〉m〈/sub〉〈/em〉), pH value, aldehyde ethanol ratio (〈em〉R〈sub〉a〈/sub〉〈/em〉) and ethanol ratio (〈em〉R〈sub〉e〈/sub〉〈/em〉), were studied and optimized adopting grafting rate (〈em〉G〈sub〉r〈/sub〉〈/em〉) as the optimizing index, the ultraviolet-visible spectrophotometry as characterization method, and the obtained optimal modification conditions were 〈em〉d〈/em〉 = 3.3 μm, 〈em〉T〈sub〉a〈/sub〉〈/em〉 = 120 °C, 〈em〉T〈sub〉m〈/sub〉〈/em〉 = 45 °C, 〈em〉t〈sub〉m〈/sub〉〈/em〉 = 30 h, pH = 6.0, 〈em〉R〈sub〉a〈/sub〉〈/em〉 = 1:10 and 〈em〉R〈sub〉e〈/sub〉〈/em〉 = 100%. Under the optimal conditions, 〈em〉G〈sub〉r〈/sub〉〈/em〉 of glutaraldehyde arrived at 50%. Thereafter, a series of modified titanium dioxide with 〈em〉G〈sub〉r〈/sub〉〈/em〉 in the range of [8%, 46%] and with 〈em〉G〈sub〉r〈/sub〉〈/em〉 = 30% obtained from different modification conditions were adopted to study the immobilization of penicillin G acylase (PGA), during this process, the ultraviolet-visible spectrophotometry of 6-aminopenicillanic acid was conscripted as characterization method, the enzyme loading capacity (〈em〉ELC〈/em〉), the enzyme activity (〈em〉EA〈/em〉) and enzyme activity retaining ratio (〈em〉EAR〈/em〉) were explored, and results documented with the increase of 〈em〉G〈sub〉r〈/sub〉〈/em〉, 〈em〉ELC〈/em〉, 〈em〉EA〈/em〉 and 〈em〉EAR〈/em〉 increased. As 〈em〉G〈sub〉r〈/sub〉〈/em〉 kept as a similar level, 〈em〉ELC, EA〈/em〉 and 〈em〉EAR〈/em〉 also showed a similar value. Finally, the structure of titanium dioxide, glutaraldehyde modified titanium dioxide and PGA immobilized titanium dioxide was characterized by the flourier transform infrared spectroscopy (FTIR), and results exhibited aimed samples were obtained successfully.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718312792-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Priya A., Prabhakarn Arunachalam, Selvi A., Madhavan J., Abdullah M. Al-Mayouf〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The present study demonstrates the synthesis of pure bismuth iron tungstate (BiFeWO〈sub〉6〈/sub〉) and tungsten oxide (WO〈sub〉3〈/sub〉) nanorods by simple co-precipitation and hydrothermal methods respectively. Likewise, BiFeWO〈sub〉6〈/sub〉/WO〈sub〉3〈/sub〉 nanocomposites of different compositions (1, 2 and 3 wt %) were fabricated via convenient wet-chemical route. The fabricated BiFeWO〈sub〉6〈/sub〉/WO〈sub〉3〈/sub〉 nanocomposites were investigated by numerous methods like X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDS) and photoelectrochemical (PEC) studies. Moreover, the photodegradation efficiency of the fabricated composites was demonstrated by photodegradation of Rhodamine B (RhB) under visible-light illumination. In particular, photodegradation results revealed the improved photocatalytic performance of 1% BiFeWO〈sub〉6〈/sub〉/WO〈sub〉3〈/sub〉 than the independent WO〈sub〉3〈/sub〉. This observed enhancement was credited to the restricted recombination rate of charge carriers by the composites leads to their separation. The as-synthesized BiFeWO〈sub〉6〈/sub〉/WO〈sub〉3〈/sub〉 photocatalytic materials were found to possess a reasonably good photostability, reusability and superior photocatalytic performances than the pure WO〈sub〉3〈/sub〉. Therefore, it can be used as a potential photocatalysts towards elimination of various organic pollutants present in aqueous environment. Further, a schematic charge transfer mechanism was also proposed in the present study.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718310781-ga1.jpg" width="211" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Zahra Mohammadizadeh Tahroudi, Amir Razmjou, Mojtaba Bagherian, Mohsen Asadnia〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Over the last decade, polydopamine (PDA) has attracted significant attention due to its material-independent coating ability, process simplicity, and its powerful capabilities for ad-layer formation. However, its long coating time (24 h) has limited its application in industrial scale. To address this issue, oxidants such as (NH〈sub〉4〈/sub〉)〈sub〉2〈/sub〉S〈sub〉2〈/sub〉O〈sub〉8,〈/sub〉 CuSO〈sub〉4,〈/sub〉 and NaIO〈sub〉4〈/sub〉 were introduced to enhance the coating kinetically. Although NaIO〈sub〉4〈/sub〉, among all the oxidants, was reported as the most efficient one, its high stoichiometric ratio of 2 between the oxidant and dopamine makes it costly and less attractive. Here, KMnO〈sub〉4〈/sub〉 is introduced as a new water-soluble oxidant which can substantially reduce the PDA coating to few minutes in a single reaction process with a chance to adjust its thickness without losing PDA intrinsic modification capability. At a KMnO〈sub〉4〈/sub〉/dopamine ratio of 0.4, a coating speed of 750 nm/h was achieved, which is 25 times higher than that of NaIO〈sub〉4〈/sub〉 at similar oxidant/dopamine ratio. The KMnO〈sub〉4〈/sub〉-assisted PDA coating was utilized to introduce an efficient and inexpensive method to convert glass materials to surfaces with durable UV shielding property. Finally, the reducibility and ad-layer formation ability of PDA layer were used to develop silver, copper, and ZIF8 composite PDA layer to adjust the UV protection level.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718307209-ga1.jpg" width="355" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Jie Zeng, Zili Li, Hao Peng, Xiaogang Zheng〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉ZnO-coated Sm〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 (Sm〈sub〉2〈/sub〉O〈sub〉3〈/sub〉@ZnO) nano-heterostructure was prepared for the visible light driven photodegradation of RhB. Core-shell Sm〈sub〉2〈/sub〉O〈sub〉3〈/sub〉@ZnO composites exhibited the enhanced photocatalytic activity compared with pure Sm〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 and ZnO nanoparticles alone for RhB removal. Sm〈sub〉2〈/sub〉O〈sub〉3〈/sub〉@ZnO with the ZnO thickness of around 10 nm presented the best photocatalytic capacity and slightly deactivated after five cycle times. It’s attributed to the extended light-harvesting capability of the core-shell heterostructure toward visible light region and the tunneled valence band holes of Sm〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 at the interface between Sm〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 core and ZnO shell. The attenuated photocatalytic activity of Sm〈sub〉2〈/sub〉O〈sub〉3〈/sub〉@ZnO in subsequent reuse process was ascribed to the change of chemical surface composition of Sm〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 under visible light irradiation. ESR results indicated that 〈sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉O〈sub〉2〈/sub〉〈sup〉−〈/sup〉 radical was main responsible for the photocatalytic performance of Sm〈sub〉2〈/sub〉O〈sub〉3〈/sub〉@ZnO.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718307647-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Sima Saeidy, Ali Nasirpour, Gholamreza Djelveh, Alina-Violeta Ursu, Cédric Delattre, Guillaume Pierre, Philippe Michaud〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Solutions of Asafoetida gum (2% w/w) were used to prepare oil in water emulsion with various oil/gum solution ratios (0.5, 1.0, 2.0, 3.0 and 4.0 v/v). Stability and rheological properties of the emulsions were examined over 28 days of storage at 20 °C. It was revealed that increasing oil volume fraction enhanced the emulsion stability. The results of creaming test showed that emulsions containing oil/gum solution ratio of more than 2.0 (v/v) displayed suitable emulsion stability. Droplet size measurements and microscopic images were representative of flocculation and coalescence with increasing oil volume fraction and time of storage. Emulsion droplet size was increased from 11.11 ± 0.99 μm to 64.01 ± 0.47 μm by increasing oil/gum solution from 0.5 to 4.0. Viscosity got higher values with increasing in oil volume fraction but reduced during the storage time. According to Herschel-Bulkely model, shear thinning behavior was determined for all emulsion samples.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718313311-ga1.jpg" width="280" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 562〈/p〉 〈p〉Author(s): Ping Jiang, Lei Zhang, Jijiang Ge, Guicai Zhang, Haihua Pei〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper investigates the effects of the SiO〈sub〉2〈/sub〉 nanoparticle mass concentration (w/v %) and oleic acid imidazoline mass fraction (w/w %) on the property of the emulsion stabilized jointly by SiO〈sub〉2〈/sub〉 and oleic acid imidazoline, with SiO〈sub〉2〈/sub〉 nanoparticles initially dispersed in different phases. In the experiment, the SiO〈sub〉2〈/sub〉 nanoparticle mass concentration in the aqueous or oil phases is fixed, and the surfactant mass fraction in oil is gradually increased, changing the emulsion from oil-in-water into water-in-oil. Moreover, in these cases, the required oil-soluble surfactant mass fraction for phase inversion is relatively low, with solid nanoparticles initially dispersed in water. Then, the surfactant mass fraction in oil is kept constant, and the emulsion type is changed from the water-in-oil into the oil-in-water by raising up the SiO〈sub〉2〈/sub〉 mass concentration in water or oil. Furthermore, under these conditions the solid nanoparticle mass concentration is higher with solid nanoparticles primarily dispersed in water than that in the case of solid nanoparticles initially placed in oil. The mechanism behind the emulsion type transition is analyzed by measuring the emulsion droplet size and rheological property of different emulsion systems. It is concluded that the difference regarding the initial dispersion medium of the solid nanoparticle affects the adsorption proportion of the solid nanoparticle and oleic acid imidazoline, the adsorption morphology, and the overall wettability of the interfacial stabilizer, which consequently impacts the property of the emulsion.〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): E.L. Brito, D.N. Gomes, C.C. Plá Cid, J.C.R. de Araújo, F. Bohn, L. Streck, J. L.C. Fonseca〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Hybrid magnetic composites are materials with great potential for use in biomedicine and effluent treatments, as their organic phase may be used in the adsorption/release of pollutants/drugs and their magnetic properties for separation/transport of particulate systems based on these materials. In this work we obtained magnetic composite particles made of magnetite nanoparticles dispersed in a polymeric matrix resultant from the formation of interpolyelectrolyte complexes based on chitosan and poly(sodium 4-styrenesulfonate). Non-stoichiometric positive and negatively charged interpolyelectrolyte complexes were obtained and characterized via thermogravimetry, Fourier transform infrared spectroscopy, X-ray diffraction analysis, transmission electron microscopy, zeta potentiometry, and vibrating sample magnetometry. The samples obtained in this work showed that nanometric magnetite was incorporated to these systems and that the resultant composites were superparamagnetic. Preliminary tests showed that the composites may be used both in the sorption of cationic and anionic drugs.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311981-ga1.jpg" width="261" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Hengwei Qiu, Jun Guo, Minqiang Wang, Shangdong Ji, Minghui Cao, Muhammad Amin Padhiar, Arshad Saleem Bhatti〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉There is an imperious demand on developing of self-cleaning surface enhanced Raman scattering (SERS) substrates, for eliminating traditional single-use substrates. Herein, ternary flexible membranes of reduced graphene oxide (r-GO) supporting Ag meso-flowers (Ag-MFs) and phenyl-modified graphitic carbon nitride nanosheets (PCNs) were fabricated for photocatalysis-driven self-cleaning SERS detection. In-situ growth of Ag-MFs with tunable morphology (such as coral-like, urchin-like, highly-branched, etc.) on r-GO surfaces provide abundant options for optimizing SERS detection limit, and thus, these PCNs/Ag-MFs@r-GO membranes exhibited strong SERS activity attributed to high density of intraparticle “hotspot” in Ag-MFs and preconcentration ability to probe molecules via π-π stacking. Among these membranes, the optimum PCNs/Ag-MFs@r-GO membrane shown a detection limit of 10〈sup〉−15〈/sup〉 M for rhodamine 6G (R6G) molecules, and this membrane could effectively remove probe molecules due to the excellent photocatalytic activity. We used R6G or methylene blue (MB) molecules for investigating the self-cleaning repeatability and stability of this PCNs/Ag-MFs@r-GO membrane, and the signal intensity for SERS detection maintained a high degree of 95% after five cycle-runs. Besides, this PCNs/Ag-MFs@r-GO membrane can be used as a high-efficiency filter membrane for simultaneous detection and purification in wastewater treatment (10 mg/mL imidacloprid solution as the example).〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718307106-ga1.jpg" width="214" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Daniel V. Gonçalves, Mayara A.G. Paiva, José C.A. Oliveira, Moises Bastos-Neto, Sebastião M.P. Lucena〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Monocomponent adsorption of hydrogen sulfide and multicomponent adsorption with CO〈sub〉2〈/sub〉 and CH〈sub〉4〈/sub〉 mixtures were predicted in two samples of commercial activated carbons. We perform Monte Carlo calculations in the grand canonical ensemble in representative slit-pores of each carbon material and proposed a new energy parameter for H〈sub〉2〈/sub〉S-carbon interaction from experimental adsorption heat in selected activated carbons. Further analysis of adsorption in representative pores demonstrated the importance of ultramicropores in H2S retention and a cooperative effect of CO〈sub〉2〈/sub〉 molecules favoring H〈sub〉2〈/sub〉S adsorption. To the best of our knowledge this is the first time that a method based on molecular simulation is proposed to predict H〈sub〉2〈/sub〉S adsorption on carbon. This study contributes to a better understanding of the role of pore size distribution and adsorption regimes in carbon materials.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571831241X-ga1.jpg" width="389" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Roshan Nazir, Uttaran Basak, Surojit Pande〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉RuO〈sub〉2〈/sub〉 nanorod (NR), an efficient and stable catalyst for hydrogen and oxygen evolution reaction is developed via wet-chemical route. Initially, a carbon slurry has been prepared using glucose and urea via heating at 140 °C for 6 h. During the preparation of carbon slurry Ru〈sup〉3+〈/sup〉 salt has been added to disperse homogeneously. Finally, calcination at 500 °C for 10 h has been performed using homogeneously distributed Ru〈sup〉3+〈/sup〉 ion in carbon slurry to get RuO〈sub〉2〈/sub〉 NR. The synthesized RuO〈sub〉2〈/sub〉 NR has been well characterized using FESEM, TEM, PXRD, and XPS analysis. The average aspect ratio of a single RuO〈sub〉2〈/sub〉 rod is ∼4.37. The synthesized RuO〈sub〉2〈/sub〉 NR has been used extensively as an electrocatalyst for hydrogen and oxygen evolution reaction. RuO〈sub〉2〈/sub〉 NR shows cathodic potential of −130 mV vs. RHE to achieve current density of 10 mA/cm〈sup〉2〈/sup〉 during hydrogen evolution reaction. Whereas, for oxygen evolution 1.508 V vs. RHE is required to generate 10 mA/cm〈sup〉2〈/sup〉 current density. Electrochemically active surface area and Tafel slope have been calculated to exhibit better activity of RuO〈sub〉2〈/sub〉 NR as compared to commercial RuO〈sub〉2〈/sub〉. The overall electrocatalysis mechanism has also been discussed in detail.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718313189-ga1.jpg" width="250" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): He Zhang, Chenlu Bao, Jinglei Yang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, hollow glass bubbles (HGBs) of about 70 μm with through-holes of about 5 μm were successfully separated from a commercialized product and were used as targets to be sealed/covered by GO sheets of size about 24 μm. Firstly, these HGBs were treated with poly(ethyleneimine) (PEI) cross-linked polydopamine (PDA) to positively charge their outer surface. After treatment, the outer surface of HGBs was uniformly deposited with PDA nano-particles. During sealing/covering process, GO sheets were successfully attracted to the PDA modified HGBs by electrostatic force between the negatively charged GO sheets and positively charged HGBs introduced by the deposited PDA nano-particles, and were anchored by PDA nano-particles at the outer surface to avoid sucking of GO sheets into HGBs through the holes. While most of HGBs were tightly sealed/covered, some of them were partially sealed due to the fractured or collapsed GO sheets on the through-holes.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311506-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Jiamin Yu, Jian Zhang, Shiying Song, Hai Liu, Zizhang Guo, Chenglu Zhang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Activated carbon (AC) derived from 〈em〉Phragmites Australis〈/em〉 (PA) with phosphoric acid activation as a low-cost adsorbent is extensively used in water treatment. In this study, a novel manganese formate hydrate (MFH) in-situ modified activated carbon (AC-MFH) has been proposed and investigated. The physical and chemical characteristics of adsorbents were characterized by N〈sub〉2〈/sub〉 adsorption/desorption, Fourier transform infrared (FTIR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results showed that AC-MFH had more microporous structures and surface oxygen-containing functional groups than AC. The Ni(II) adsorption behaviors of adsorbents were investigated by batch experiments, the results suggested that AC-MFH showed 20% higher Ni(II) adsorption capacity than that of AC and the associated adsorption isotherms and kinetics well fitted to the Langmuir model and pseudo-second-order model, respectively. The Ni(II) adsorption mechanisms of AC-MFH were investigated by FTIR and XPS analysis. These results indicated that the adsorption of Ni(II) mainly depended on the surface chemistry between the Ni(II) and surface oxygen-containing functional groups.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718313165-ga1.jpg" width="311" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): F. Varenne, H. Hillaireau, J. Bataille, C. Smadja, G. Barratt, C. Vauthier〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The development of dispersed material of small size in various fields is conditioned by their quality control. Size and surface properties such as zeta potential of dispersed materials employed in nanomedecine have been identified as key physico-chemical parameters as they may influence their 〈em〉in vivo〈/em〉 fate. These physico-chemical parameters can be determined using appropriate methods described in the ISO standards including dynamic light scattering and electrophoretic light scattering for evaluation of size and zeta potential respectively. Accurate measurements are paramount to ensure reliable results for material characterization. Reliability of measurements was ensured by a series of handling precautions and quality criteria for good measurements to be applied for the validation of the protocols. The present work was aimed to evaluate the application of validated protocols to characterize dispersed materials based on the analysis of quality criteria. The size measurement protocol was applied to evaluate size of a wide range of dispersed materials including polymer nanoparticles. However, this protocol was unsuitable for size evaluation of particles characterized by a high density and magnetic particles with size in the upper limit of the instrument. The validated protocol for zeta potential evaluation was suitable to evaluate zeta potential of polymer nanoparticles but not for the evaluation of zeta potential of dense nanoparticles.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571830983X-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Gergana M. Radulova, Tatiana G. Slavova, Peter A. Kralchevsky, Elka S. Basheva, Krastanka G. Marinova, Krassimir D. Danov〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Colloidosomes provide a possibility to encapsulate oily substances in water in the form of core-in-shell structures. In this study, we produced microcapsules with shell from colloidal particles, where the interparticle openings are blocked by mixed layers from polymer and surfactant that prevent the leakage of cargo molecules. In other words, the particles and polymer play the role of bricks and mortar. For this goal, we used hydrophilic silica particles, which were partially hydrophobized by the adsorption of potassium oleate to enable them to stabilize Pickering emulsions. Various polymers were tested to select the most appropriate one. The procedure of encapsulation is simple and includes single homogenization by ultrasound. The produced capsules are pH responsive. They are stable in aqueous phase of pH in the range 3–6, but at pH 〉 6 they are destabilized and their cargo is released. With the optimized formulation of silica particles, polymer, oleate and NaCl, we were able to encapsulate various oils and fragrances, such as tetradecane, limonene, benzyl salicylate and citronellol. All of them have a limited and not too high solubility in water. In contrast, no stable microcapsules were obtained with oils that either have zero water solubility (mineral and silicone oil) or higher water solubility (phenoxyethanol and benzyl alcohol). By analysis of results from additional interfacial-tension and thin-film experiments, we concluded that a key factor for obtaining stable capsules is the irreversible adsorption of the polymer at the oil/water interface. The hydrophobization of the particles by surfactant adsorption (instead of silanization) plays an important role for the pH responsiveness of the produced capsules. The obtained information about the role of various factors for the stabilization of microcapsules, which are based on the brick-and-mortar concept, can be further used to achieve better stability; selection of polymers that are appropriate for different classes of oils, as well as for the production of smaller capsules stabilized by nanoparticles.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718312391-ga1.jpg" width="462" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Yousef Kazemzadeh, Mohammad Sharifi, Masoud Riazi, Hosein Rezvani, Morteza Tabaei〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study intends to take a new look at the application of NPs as a nanocomposite form for the first time to gain the most from the effects of them for EOR purposes. For this, TiO〈sub〉2〈/sub〉/SiO〈sub〉2〈/sub〉 and Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉/SiO〈sub〉2〈/sub〉 nanocomposites were first synthesized and investigated for EOR purposes by different experiments, including contact angle, interfacial tension (IFT), injected fluid viscosity, NPs retention in porous medium and carbonate sand pack floodings. The results showed that each NP and nanocomposite presents a distinctive behavior depending on the pressure of the porous medium, with all bringing higher oil production compared to that of seawater (SW) injection. At the ambient pressure, the dominant mechanism during TiO〈sub〉2〈/sub〉 and TiO〈sub〉2〈/sub〉/SiO〈sub〉2〈/sub〉 nanofluid injection was found to be the IFT reduction along with wettability alteration. Whereas, at the intermediate pressure (1500 psi), the wettability alteration by TiO〈sub〉2〈/sub〉 NPs and TiO〈sub〉2〈/sub〉/SiO〈sub〉2〈/sub〉 nanofluids was regarded to be the dominant EOR mechanism and recorded a recovery factor of 60 and 72%, respectively. At the high pressure (3500 psi), the dominant mechanism was observed to be asphaltene adsorption by Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 NPs and Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉/SiO〈sub〉2〈/sub〉 nanocomposites leading to the ultimate recovery factor of 56 and 69%, respectively. The highest incremental recovery for NPs was observed for tertiary injection of SiO〈sub〉2〈/sub〉 nanofluid at 1500 psi, which increased the oil recovery by 14%. Whereas, Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉/SiO〈sub〉2〈/sub〉 and TiO〈sub〉2〈/sub〉/SiO〈sub〉2〈/sub〉 nanofluids increased the oil recovery by 24 and 23% at the pressures of 3500 and 1500 psi, respectively. This confirms the efficient role of the synthesized nanocomposites for improved oil recovery. Finally, the results of absorbance measurements of the inlet and outlet of the sand pack during Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉/SiO〈sub〉2〈/sub〉 nanofluid injection indicated a 32.4% NPs retention in the porous medium.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718312020-ga1.jpg" width="322" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Ruoqian Zhang, Yuanyuan Liu, Yang An, Zeyan Wang, Peng Wang, Zhaoke Zheng, Xiaoyan Qin, Xiaoyang Zhang, Ying Dai, Baibiao Huang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Effective and selective removal of Pb(II) from aqueous solution is highly desirable, but it is still a great challenge. We report here a water stable metal-organic frameworks (CAU-7-TATB), and the ligands contain N, which provides binding sites for metal ions. CAU-7-TATB exhibits fast adsorption kinetics, high adsorption capacity towards Pb(II). More importantly, CAU-7-TATB remains high prior adsorption towards Pb(II) in the presence of interfering ions like Cr(III), Co(II), Ni(II), Mn(II), Zn(II), Mg(II) and Ca(II), which is potentially applicable in removing Pb(II) from industrial water.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718313207-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): In-Ho Yoon, Suk Bon Yoon, Chong-Hun Jung, Chorong Kim, Seonbyeong Kim, Jei-Kwon Moon, Wang-Kyu Choi〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A foam with high stability for the efficient decontamination of radioactive materials has been prepared by using well-dispersed mesoporous silica nanoparticles (NPs). Three different types of silica NPs were tested: solvent-extracted mesoporous silica (SMS) NPs, calcined mesoporous silica (CMS) NPs, and commercial silica (M-5) NPs. The stability and decontamination efficiency of the foam prepared using SMS NPs was higher than those using other silica NPs. The liquid volume in the foam with the SMS NPs are 10–25 times greater than those containing the CMS and M-5 NPs. The stability of the decontamination foam consisting of SMS NPs is higher because of its higher viscosity; the SMS NPs sample contains a larger number of particles per unit volume and has smaller particle sizes than the CMS and M-5 NPs samples. To investigate the dispersion-agglomeration properties of the silica NPs, the size distributions of the silica NPs in the decontamination foam solutions were determined by using dynamic light scattering. The SMS NPs are smaller than the CMS and M-5 NPs in the decontamination foam solution. For stainless steel 304 and carbon steel specimens corroded with the radionuclide 〈sup〉60〈/sup〉Co, decontamination foams containing SMS NPs were found to exhibit a decontamination efficiency 20–40% greater than those of the foams containing the other silica NPs. This superior efficiency arises because the foams prepared with SMS NPs exhibit improved stability and their liquid component can hold larger amounts of the decontamination agent.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571831286X-ga1.jpg" width="355" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Zhiqi He, Yingzhen Ma, Paschalis Alexandridis〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Ionic liquids are low-melting salts that have novel properties and are very useful as solvents or additives on the basis of the intermolecular interactions operating between the ionic liquid ions and various solute or solvent molecules. In this work, we compare the effects of ionic liquids and salt on the micellization of a representative amphiphilic block copolymer poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO), Pluronic P123 (EO〈sub〉20〈/sub〉PO〈sub〉70〈/sub〉EO〈sub〉20〈/sub〉). Ethylammonium nitrate (EAN) is used as a representative protic ionic liquid, to compare with its corresponding classic salt, ammonium nitrate (NH〈sub〉4〈/sub〉NO〈sub〉3〈/sub〉), and with 1-butyl-3-methylimidazolium tetrafluoroborate (BmimBF〈sub〉4〈/sub〉) as a representative aprotic ionic liquid. The protic ionic liquid EAN is similar with the classic salt NH〈sub〉4〈/sub〉NO〈sub〉3〈/sub〉 in promoting PEO-PPO-PEO micellization; they both increase the micellization entropy and lower the micellization enthalpy at higher concentration. The hydrogen bonding between EAN and PEO, and the ethyl group on the EAN cation, both assist the solvation of PEO-PPO-PEO molecules, which partially offsets their dehydration caused by the ionic liquid ions. These lead to a less significant change of the micellization thermodynamics parameters by EAN compared to NH〈sub〉4〈/sub〉NO〈sub〉3〈/sub〉. The aprotic ionic liquid BmimBF〈sub〉4〈/sub〉 exhibits effects that are opposite to those of the protic ionic liquid EAN. The micellization enthalpy of PEO-PPO-PEO significantly increases in the presence of BmimBF〈sub〉4.〈/sub〉 The hydrogen bonds formed between BmimBF〈sub〉4〈/sub〉 and PEO-PPO-PEO, along with nonpolar butyl clusters formed by Bmim cations assist the solvation of Pluronic P123, which in turn hinders micellization. This work compares for the first time the effects of a protic ionic liquid with a classic salt and with an aprotic ionic liquid on amphiphile micellization in aqueous solution in terms of thermodynamics.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311737-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Sadafara A. Pillai, Vijay I. Patel, Debes Ray, Haridas Pal, Vinod K. Aswal, Pratap Bahadur〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The interaction of cinnamic acid (CA) and its analogues viz. 〈em〉p〈/em〉-coumaric acid (PCA) and caffeic acid (CFA) with core-shell micelles of a moderately hydrophobic Pluronic〈sup〉®〈/sup〉 P123 has been investigated using cloud point (CP), viscosity, dynamic light scattering (DLS), small-angle neutron scattering (SANS) and steady-state fluorescence measurements. These solubilizates alter micellar behaviour of copolymer solution dependant on their hydrophobicity. P123 micelles exhibit time-dependent restructuring and responsive growth processes at different rates, depending on pH and in the presence of additives. Thus, restructuring and growth of P123 micelles can be easily tuned up to a substantial extent just by changing the concentration of the additives and the pH of the solution. Considering the medical applications of cinnamic acid and its analogues and considering use of Pluronics〈sup〉®〈/sup〉 in drug delivery systems, the present study can provide important insight of the possible time-dependant delivery mechanism of drugs.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718312305-ga1.jpg" width="294" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): B. İlhan, C. Annink, D.V. Nguyen, F. Mugele, I. Siretanu, M.H.G. Duits〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Colloidal particles often display a surface topography that is smooth down to the nanometer scale. Introducing roughness at this length scale can drastically change the colloidal interactions, adsorption at interfaces and bulk flow behavior. We report on a novel, simple method to induce and control nano-scale roughness on (water based) polymer latex colloids. Reducing the amount of dissolved gases in the aqueous phase from the electrolyte solution surrounding the particles, generates self-structured surface asperities with an amplitude that can be tuned via temperature and repetition of the treatment. Due to the viscoelastic nature of the polymeric asperities, a mild thermal treatment below the glass transition temperature can be used for nanostructure relaxation, so that the particles can recover their original topography, making this method fully reversible. Roughness can thus be controlled without affecting the chemical composition of the colloidal surface. Experiments for varying particle size, polymer type and surface chemistry suggest a broad applicability of our method.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718312263-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Sandeep Hatte, Riju Dhar, Lalit Bansal, Suman Chakraborty, Saptarshi Basu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Confinement effects may trigger certain non-trivial characteristics of droplet evaporation, which may incur far-reaching implications in practical scenarios. In effect, the vapor mediated interactions in a confined droplet may alter its intrinsic evaporation characteristics altogether, primarily as a consequence of significant increase in droplet lifetime due to enriched accumulation of the vapor field in the vicinity. Here, we derive a universal scaling law for the evaporation lifetime of a geometrically confined sessile droplet, appropriate to a wide gamut of droplet-substrate combinations. With asymptotic convergence to the classical picture in case of an unconfined droplet, the validity of our scaling law for droplet lifetime is comprehensively tested and benchmarked against a wide range of experimental data sets. These findings may turn out to be of profound importance in several emerging applications including micro-scale combustion and droplet based microfluidic technology.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718313116-ga1.jpg" width="442" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Satoshi Nakata, Mio Nomura, Yuta Yamaguchi, Mafumi Hishida, Hiroyuki Kitahata, Yukiteru Katsumoto, Mitsuhiro Denda, Noriyuki Kumazawa〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To elucidate the effect of polyols on a phospholipid molecular layer, different polyols with the formula H-(CH(OH))〈em〉〈sub〉m〈/sub〉〈/em〉-H (〈em〉m〈/em〉 = 2–6) were added to a phospholipid (1,2-dipalmitoleoyl-〈em〉sn〈/em〉-glycero-3-phosphoethanolamine (DPoPE)) solution above and below the phase transition temperature between the lamellar and inverted hexagonal phases. As for the surface pressure (〈em〉π〈/em〉)−surface area (〈em〉A〈/em〉) isotherm of the phospholipid monolayer at the air-water interface, 〈em〉π〈/em〉 at a constant value of 〈em〉A〈/em〉 increased with increasing 〈em〉m〈/em〉, especially for xylitol (〈em〉m〈/em〉 = 5) and sorbitol (〈em〉m〈/em〉 = 6). Small angle X-ray scattering (SAXS) and Fourier transform IR spectrometry (FT-IR) were used to evaluate the interaction between DPoPE and the polyol molecules. The experimental results suggest that the number of CH(OH) groups in the polyol plays an important role in the characteristic interaction between DPoPE and the polyol in both the lamellar and inverted hexagonal phases.〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Xihao Pan, Gancheng Zuo, Ting Su, Siyao Cheng, Yufan Gu, Xiaoliang Qi, Wei Dong〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Magnetic particle is a promising class of materials to absorb harmful contaminants for their easy collecting property with magnetic response. Here, we report a novel kind of polycarboxylic magnetic polydopamine sub-microspheres (Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@PDA-COOH) facilely synthesized by coating polydopamine (PDA) onto the surface of magnetic nanocrystal clusters (Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉). Then the sub-microspheres were modified with mercaptosuccinic acid (MSA) to have polycarboxylic groups on their surface. Fourier transform infrared spectroscopy (FT-IR) was used to demonstrate the desired chemical structure. The unique morphology and particle size distribution were confirmed by Transmission electron microscopy (TEM). Malachite green (MG) was used as a model to test the adsorption capacity of the magnetic sub-microspheres. Besides, factors such as initial MG concentration, initial solution pH, and contact time were systematically studied for this adsorption process. Results showed that the maximum adsorption capacity of Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@PDA-COOH could reach up to 331.0162 mg/g (MG/ sub-microspheres), much higher than that of Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@PDA. The adsorption kinetics and adsorption isotherms could be well described by pseudo-second-order kinetic model and Freundlich isothermal model. Moreover, Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@PDA-COOH sub-microspheres can retain the high adsorption ability after five using-cycles. Therefore, the synthesized Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@PDA-COOH can be a high-efficiency adsorbent in the field of wastewater treatment.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718313177-ga1.jpg" width="296" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): S.Y. Misyura, R.S. Volkov, A.S. Filatova〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The interaction of two drops is studied experimentally: a small droplet falls on a large sessile drop located on a hot wall. The temperature of the falling droplet is 20 °C, and the wall temperature is 80 °C. It is well known that the surfactant suppresses the Marangoni flow (〈em〉Ma〈/em〉). This paper considers the influence of surfactant in the presence of several key factors – dynamic and thermal ones. When a droplet impacts a liquid layer, the heat and mass transfer is associated with both the dynamic factor (inertial forces and pressure “jumps” inside the droplet) and the thermal factor (an increase in the surface temperature gradient). The novelty of this work is that it for the first time shows that at the moment of extremely short-term interaction of drops, there is 7–8 times increase of velocity inside the drop. In this case, the determining effect on the convection enhancement is associated with thermocapillary convection, and the role of the dynamic factor is insignificant. The influence of graphite particles and surfactant of sodium dodecyl sulphate (SDS) has been investigated. The velocity “jump” resulting from the fall of the water droplet with surfactant is 4 times smaller as compared to the fall of surfactant-free droplet. The instantaneous velocity fields inside the sessile drop have been experimentally studied using Micro Particle Image Velocimetry (Micro PIV). The obtained results are of great importance for the correct modeling of heat and mass transfer and have a wide application for sprays, as well as for the multiphase flows.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311828-ga1.jpg" width="233" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Manviri Rani, Uma Shanker〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Discharge of dyes (major industrial coloring agents ∼700,000 tonnes) in environment is of concern due to their high perseverance, toxicity and carcinogenicity. Thus, effective elimination of organic dye (methylene blue) was carried out by poly(methyl methacrylate) (PMMA) incorporated metal oxide nanocomposites. Spherical and semi crystalline Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-PMMA, ZnO-PMMA, CuO-PMMA and Ni〈sub〉2〈/sub〉O〈sub〉3〈/sub〉-PMMA were self-assembled via green route employing 〈em〉Sapindus mukkorossi〈/em〉 (Plant extract). At optimised conditions (dye conc: 2 mg L〈sup〉−1〈/sup〉; catalyst: 80 mg: neutral pH) MO-PMMA showed maximum degradation efficiency (90–99%; t〈sub〉1/2〈/sub〉 = 5.1–5.6 h) than that of individual MO (74–80%; t〈sub〉1/2〈/sub〉 = 5.8–6.8 h) credited to improved thermal stability and surface area via incorporation of MO into PMMA matrix. Like MO, highest degradation with ZnO-PMMA (99%; X〈sub〉m〈/sub〉 = 0.135 mg/g) followed by Ni〈sub〉2〈/sub〉O〈sub〉3〈/sub〉-PMMA (98%), CuO-PMMA (93%) and Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-PMMA (90%) could be attributed to its high surface area (85.32 m〈sup〉2〈/sup〉 g〈sup〉−1〈/sup〉) and least zeta potential (-22.5 eV). Adsorption of MB over catalyst was statistically significant with Langmuir isotherms (R〈sup〉2〈/sup〉: 0.99 and p value: 0.0005) and first order kinetics with greatly reduced half-life. Comparatively higher degradation in sunlight than dark, and involving hydroxylation, oxidation and ring opening clearly reinforced boosted oxidation of MB by 〈sup〉〈img src="https://sdfestaticassets-us-east-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉OH. Moreover, reduction in degradation (50-40%) in presence of 〈sup〉〈img src="https://sdfestaticassets-us-east-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉OH scavengers supported the photocatalytic activity of nanocomposites. MB was degraded into minor non-toxic by-products such as (Z)-hexa-3,5-dien-1-ol and (Z)-buta-1,3-dien-1-ol and benzoquinone. Overall, by virtue of greater active sites, high surface activity and semiconducting nature, the as-synthesized MO-PMMA photocatalyst is a promising, recyclable (n = 10) and eco-friendly panorama in the treatment of organic- pollutants in water and wastewater-treatment.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311117-ga1.jpg" width="220" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Esra Kasapgil, Ilke Anac, H.Yildirim Erbil〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The subject of slippery liquid-infused porous surfaces (SLIPS) have attracted many researchers due to their excellent liquid repellent properties and widespread usage in many fields such as anti-wetting, anti-icing, omniphobic, self-cleaning and anti-biofouling surfaces. Choosing an environmentally friendly, durable lubricant and easy-clean preparation method is very important when designing SLIPS. In this work, fluorine-free, transparent, water and oil repellent slippery liquid-infused porous surfaces (SLIPS) were successfully obtained via infusing silicone oil, which is a fluorine free and durable liquid, onto superhydrophobic polysiloxane nanofilament surfaces. Polysiloxane nanofilaments were prepared on activated glass slides by an easy, clean and environmentally friendly gas phase reactions of n-propyltrichlorosilane (n-PTCS) for the first time and also methyltrichlorosilane (MTCS) and the results were compared. Advancing contact angles of the n-PTCS based polysiloxane nanofilament layers were between 143 and 172° and contact angle hysteresis as low as 7° was obtained on these surfaces by altering the relative humidity and reaction time during filament growth. Then, transparent SLIPS were obtained by infusing silicone oil into polysiloxane filament layers of MTCS and n-PTCS. The obtained SLIPS shows excellent liquid repellency, very low contact angle hysteresis for long durations and maintains its water repellency after heating up to 80 °C for 6 days and also after exposure to continuous water droplet flow up to 2 h.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571831183X-ga1.jpg" width="496" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Kolawole Adenekan, Brenda Hutton-Prager〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Cellulose fibers were impregnated with alkyl ketene dimer (AKD) dissolved in n-heptane and carbon dioxide via sub- and supercritical impregnation techniques. The mechanistic pathways and hydrophobic performance at short and long times were investigated by contact angle (CA) analysis, scanning electron microscopy (SEM) with micrographs analyzed using Image-Pro Premier, and Fourier Transform Infrared (FTIR) analysis. The sizing development was significant after two days of treatment, and hydrophobic performance became uniform after two weeks regardless of the impregnation conditions investigated. Samples prepared at 100 and 200 bar produced more rapid development than those at higher and lower impregnation pressures, with the average CA at 200 bar and 21 °C being 140 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mo〉±〈/mo〉〈/math〉 5°. ‘Sticky’ hydrophobicity was observed on surfaces treated at 200 and 250 bar at long times (〉 140 days), and adhesive forces between the droplet (〉20 μL) and surface were observed at surface tilt angles between 0 – 180°. SEM micrographs of the impregnated samples showed a reduction in substrate pore-size area (PSA) as hydrophobicity developed with time. There was little evidence of reaction-based sizing as the characteristic ketone and ester peaks were not observed in FTIR studies. The lactone ring remained intact. The 200 bar sample showed highest peak intensity for various hydrocarbon bonds observed – suggesting the optimal solubility of AKD in supercritical carbon dioxide (scCO〈sub〉2〈/sub〉). Spreading of AKD across the fiber surfaces appeared to be the main sizing pathway, and identification of hydrogen bonding between AKD and cellulose fibers suggested a possible attachment method.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718312287-ga1.jpg" width="356" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Mittal L. Desai, Sanjay Jha, Hirakendu Basu, Rakesh Kumar Singhal, P.K. Sharma, Suresh Kumar Kailasa〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Herein, we report chicken egg white (CEW) and L-cysteine (L-Cys) as cooperative ligands for effective encapsulation of Zn-doped silver nanoclusters (Zn-doped Ag NCs) for enhancing optical properties in sensing of Hg〈sup〉2+〈/sup〉 ion and bioimaging of fungal cells (〈em〉Alternaria〈/em〉 sp.). The emission peak at 657 nm was remarkably enhanced by doping of Zn-atom into Ag NCs, suggesting the proteins of CEW and L-Cys provide good architectures for supramolecular encapsulation of Zn-Ag NCs. The quantum yield (QY) of Ag NC was improved to 13.3% due to the doping of Zn atoms into Ag NCs. The “fluorescence-off” of Zn-doped Ag NCs is proceeded by the addition of Hg〈sup〉2+〈/sup〉 ion, which exhibits detection limit of 68 nM. The other chemical species did not interfere with assay of Hg〈sup〉2+〈/sup〉 ion. We also extended the application of Zn-doped Ag NCs as a probe in imaging of fungal cells (〈em〉Alternaria〈/em〉 sp.). The CEW-L-Cys encapsulated Zn-doped Ag NCs exhibited an excellent stability and shown to be a magnificent probe for sensing and bioimaging applications, which demonstrates that Zn-doped Ag NCs as potential candidates in analytical and bioanalytical sciences.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718310859-ga1.jpg" width="237" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Nobuo Uehara〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Cationic and anionic thermoresponsive polymers were synthesized and the formation of their hydrophobic aggregates with ionic surfactants was studied at extremely low polymer concentrations. Alongside the hydrophobic interactions, electrostatic interactions between the ionic groups of the polymers and surfactants played a major role in the formation of the hydrophobic aggregates. In the absence of an ionic surfactant, extremely dilute (i.e., 0.01 wt %) polymer solutions did not become turbid, even when they were heated above the phase-transition temperature. However, above the phase-transition temperature, the polymer solutions became turbid upon the addition of a specific concentration of an ionic surfactant with the opposite charge. In contrast, no increase in the turbidity was observed when an ionic surfactant with the same charge was added to the solution, regardless of the concentration of the ionic surfactant. Even below the phase-transition temperature, the application of a fluorescent probe that responded to the hydrophobicity of its environment revealed that the ionic thermoresponsive polymers formed a hydrophobic environment with oppositely charged surfactants owing to the electrostatic and hydrophobic interactions, even though hydrophobic precipitates were not observed. Thus, the electrostatic interactions between polymers and surfactants played crucial roles in the formation of hydrophobic aggregates under extremely low concentration of the polymers as well as the hydrophobic interactions did.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718313104-ga1.jpg" width="273" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Romain Melich, Jean-Pierre Valour, Sébastien Urbaniak, Frédéric Padilla, Catherine Charcosset〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Microbubbles are increasingly used in several fields, such as medical imaging for enhanced contrast ultrasound imaging. Theses microbubbles usually consist of a gas core stabilized by surfactant molecules. In this study, a technique using Shirasu Porous Glass (SPG) membranes was used to produce perfluorocarbon microbubbles. The microbubbles obtained were characterized by their size, size distribution, and stability. The effect of several parameters on the microbubble's size was investigated related to the process (transmembrane pressure, ΔP, bubble point pressure, 〈em〉P〈/em〉〈sub〉〈em〉BP〈/em〉〈/sub〉, shear stress, 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈msub〉〈mi〉τ〈/mi〉〈mi〉w〈/mi〉〈/msub〉〈/math〉), membrane pore size, 〈em〉D〈/em〉〈sub〉〈em〉p〈/em〉〈/sub〉, and formulation (gas, surfactants in the aqueous phase). The transmembrane pressure nor the shear stress (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈msub〉〈mi〉τ〈/mi〉〈mi〉w〈/mi〉〈/msub〉〈/math〉) had influence on the microbubble's size or size distribution for ΔP/〈em〉P〈/em〉〈sub〉〈em〉BP〈/em〉〈/sub〉 〈1.5. The decrease of the membrane pore size from 1.1, 0.5, to 0.2 μm led to lower microbubble size 13.3, 6.36, and 4.42 μm, respectively, which was associated with higher size distribution 16%, 24% and 31%, respectively due to the higher Laplace pressure exerted on smaller microbubbles leading to their destabilization. With the 1.1 μm pore size membrane, perfluorocarbon microbubbles were obtained with a diameter of 13.3 μm and coefficient of variation (CV) of 16% when stabilized by sodium dodecyl sulfate (SDS), 15.6 μm with CV% of 23% when stabilized by Tween20, and 16.5 μm with CV% of 26% when stabilized by Polyoxyethylene (40) stearate (PEG40S). These low CV were indication of monodispersity. Perfluorocarbon microbubbles had a smaller size than air microbubbles due to the lower surface tension that decreased the retention force, keeping the microbubbles at the pore opening. The stability study showed that the perfluorocarbon gas greatly increased the lifetime of the microbubbles with a slight increase in size of 1.3 after 90 s compared to 2.2 for air microbubbles. Overall, the membrane technique proved to be an effective, controlled and reproducible method to produce perfluorocarbon microbubbles at a high rate ∼0.6 − 1.5 × 10〈sup〉+10〈/sup〉 microbubbles/min. The key factor that determines the microbubbles formation is the adsorption kinetics of the surfactant at the new gas–liquid interface at the pore opening.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311658-ga1.jpg" width="347" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 18 May 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Rohallah Hashemi, M.C. Amiri〈/p〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Ying-zhi Ma, Da-feng Zheng, Zhen-ye Mo, Rui-jing Dong, Xue-qing Qiu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In order to expand the application of lignin, magnetic lignin-based carbon nanoparticles (MLBCN) were synthesized using a precipitation-carbonization process and the structure was confirmed by FTIR, XRD, Raman, BET, SEM, DLS and VSM. The adsorption of MLBCN for methyl orange was consistent with the Langmuir model and pseudo-second-order model, showing monolayer adsorption, with a maximum adsorption capacity of 113.0 mg/g and chemisorption being the rate-controlling step. This process was exothermic and of entropy reduction, showing spontaneous below 35 °C. MLBCN could be used under near neutral conditions and easily regenerated. This study demonstrates that MLBCN is promising as an efficient, sustainable absorbent.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311518-ga1.jpg" width="330" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Yoko Akiyama, Yukako Matsue, Tatsuya Mori, Shigehiro Nishijima〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Polymer-surfactant complex particles formed by dilution of shampoo play an important role in the sensory properties of shampoo, but their microscopic mechanism has not been clarified yet. This study clarifies the change mechanism influencing hair surface smoothness induced by this complex. The degrees of precipitation and adsorption of the polymer-surfactant complex particles are varied by changing the sodium chloride (NaCl) concentration in the shampoo formulation; hence, the relationships between the frictional and sensory properties during rinsing, the particle formation numbers in water, and the particle adsorption rate on the hair surface are investigated. The frictional property measurement and microscopic observation of human hair treated with the various shampoo solutions confirm that two different particle types, floating and adsorptive, are formed in water during the shampoo dilution process, both of which contribute to improving the hair smoothness. Then, NaCl is added to the basic shampoo composition to control the formation of these two particle types. The particle size distribution and chemical identification show formation of submicron-sized particles mainly consisting of cationized polymer in water with less than 0.20-wt % NaCl, which do not adsorb on the hair surface. For 0.75–3.00-wt.% NaCl, polymer-surfactant complex particles are formed, which easily adsorb on hair. Finally, we propose an optimal NaCl concentration of 0.75 wt.% to obtain excellent frictional properties. The result will contribute to the formulation of cosmetic products based on microscopic mechanism.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718310410-ga1.jpg" width="232" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Kamelia Kamburova, Nelly Boshkova, Nikolai Boshkov, Genoveva Atanassova, Tsetska Radeva〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Core-shell nanocontainers (NCs) with corrosion inhibitor benzotriazole (BTA) are fabricated by electrostatic self-assembly of poly(diallyldimethylammonium chloride) (PDADMAC) and poly(acrylic acid) (PAA) on kaolinite and hematite particles. BTA is entrapped within the polyelectrolyte shell in one assembly step. The growth of the polymer shells and stability of the NCs suspensions against aggregation are followed by electric light scattering and electrophoresis The NCs loaded with BTA are incorporated into the matrix of ordinary zinc coatings by electrodeposition on steel substrates from acidic zinc sulfate solutions. The influence of the NCs on cathodic and anodic processes is analyzed in the starting zinc sulfate solution with cyclic voltammetry. The scanning electron microscopy shows random (near to uniform) distribution of the NCs in both hybrid coatings. The protective characteristics of the hybrid coatings in model medium of 5% NaCl are followed by means of potentiodynamic polarization curves, polarization resistance measurements and electrochemical impedance spectroscopy. XPS method is applied for determination of the nature of additional products appearing on the coatings as a result of the corrosion treatment. Both hybrid zinc coatings reveal improved corrosion protection of steel as compared to the pure zinc coating, the coating with kaolinite-based NCs showing better protective characteristics in comparison with the one incorporating hematite NCs.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311105-ga1.jpg" width="351" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Chen Li, Guoqing Feng, Chengwen Song, Guorong Zhong, Ping Tao, Tonghua Wang, Mihua Shao〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel electrocoagulation (EC)-carbon membrane coupling with electrochemical anodic oxidation (CM/EAO) integrated system was designed and constructed for oily wastewater treatment. Electrocoagulation was adopted as a primary unit, and the effects of many parameters, including current density, electrolyte concentration, initial pH, feed oil concentration, and operating time on pretreatment performance were investigated and optimized. Subsequently, CM/EAO was set as a secondary unit for further deep purification of the EC effluent. The results showed the integrated system had great potential for oil removal from wastewater. The EC unit could remove nearly half of COD and TOC in the feed, and the following CM/EAO unit further degraded the EC effluent, and the COD, and TOC were reduced to 13 mg/L and 22 mg/L, respectively. The mechanisms involved in each stage were proposed. A large proportion of oil droplets in oily wastewater were firstly removed by electrocoagulation process, and the remaining oil droplets were further decomposed into small molecules or even into CO〈sub〉2〈/sub〉 and H〈sub〉2〈/sub〉O by hydroxyl radicals generated from electrochemical anode oxidation reactions. The degraded intermediate products including various n-alkanes and polycyclic aromatic hydrocarbons were identified by GC〈img src="https://sdfestaticassets-us-east-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉MS.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉A novel electrocoagulation (EC)-carbon membrane coupling with electrochemical anodic oxidation (CM/EAO) integrated system was designed and constructed for oily wastewater treatment.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311154-ga1.jpg" width="455" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Andrew T. Tyowua, James M. Mooney, Bernard P. Binks〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The preparation of Janus liquid marbles containing both oil and water is reported. The marbles were prepared by coalescing an oil liquid marble with a water liquid marble mechanically on a powdered bed of omniphobic solid particles, followed by further rolling on the particle bed so as to increase the particle coating and prevent disintegration upon removal. The coalescence of the marbles involves the rarification of the particle layers around the interacting marbles followed by the fusion of their liquid cores. Upon further rolling, the marbles exhibited four characteristic shapes depending on the oil to water ratio and the stabilising solid particles. Janus marbles containing equal volumes of oil and water and stabilised by fluorinated clay particles were ‘egg-like’ in shape with the water portion remaining almost spherical compared with the oil portion. The marbles elongate and change to a ‘tadpole-like’ shape as the volume fraction of oil increases, leaving the shape of the water portion which forms the head of the tadpole intact (quasi-spherical). On the contrary, increasing the volume fraction of water did not affect the marble shape. When stabilised by fluorinated fumed silica particles, a quasi-spherical shape forms at equal oil and water volumes, but an increase in either oil or water fraction changes the shape to a puddle. The stability of the Janus marbles to evaporation depends on the vapour pressure of the encapsulated liquids, with those of higher vapour pressure evaporating faster as in the case of liquid marbles containing only one liquid. Lastly, by coalescing a cyclohexane marble containing sebacoyl chloride with a water marble containing hexamethylene diamine, resulting in the formation of Nylon 6–10 at the interface, the possibility of performing chemical reactions in the Janus oil-water liquid marbles was illustrated.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311476-ga1.jpg" width="274" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): K. Ratish Ramanan, E.J. Rifna, R. Mahendran〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The colloidal nature of wheat flour could be utilized in engineering the physical structure of food systems. Gelatinization behavior of starch in wheat flour was studied to develop a wheat hydrogel and the impact of hydrogel characteristics in drying was observed in xerogel surface structure. Effect of variation in wheat flour concentration was analyzed by least gelation concentration and pasting parameters. It showed 10% (w/v) of gelatinized wheat flour suspension can be able to form a three-dimensional polymer network during retrogradation. Influence of hydrogel formation temperature was studied by solubility, swelling power, transmittance, contact angle and surface tension at different temperatures. Increase in solubility and swelling power indicates, leaching of more starch components and binding of more water molecules. The decrease in light absorbance indicates loss of crystallinity and birefringence due to disruption of granular structure. Contact angle and surface tension showed its impact on the increase in spreading coefficient at higher temperatures. Different concentration (5–15% (w/v)) of wheat flour suspension were subjected to heat from 30 to 100 °C; at each 5% (w/v) rise in concentration and 10 °C rise in temperature, a xerogel was developed and observed. It was found that 10% (w/v) of wheat flour suspension gelatinized at 90 °C showed better integrity and surface structure without cracks and deformations. The developed xerogel could serve as a snack food and also a carrier material for bioactive components in functional foods and nutraceuticals.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718312317-ga1.jpg" width="459" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Chao Han, Ning Cai, Vincent Chan, Mingming Liu, Xiaojuan Feng, Faquan Yu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A facile strategy to incorporate dual sustained-release system in electrospun poly(lactic acid) (PLA) nanofibers is proposed for emerging applications in advanced drug delivery. Firstly, a model antimicrobial therapeutics, tetracycline hydrochloride (TCH) was blended with Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-COOH nanoparticles 〈em〉via〈/em〉 electrostatic interaction to form novel composite nanoparticles. Then the influence of Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-COOH or TCH/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-COOH nanoparticle incorporation on the morphology, porosity and hydrophilicity of electrospun PLA nanofiber membranes were elucidated. By studying drug release profiles, the newly designed TCH/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-COOH/PLA nanofibrous membrane exhibited an obvious transition of drug release mechanisms from zero order release kinetics within the initial 6 days to modulated release beyond 6 days (until 14 days) in PBS. In contrast, TCH/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-COOH and TCH/PLA nanofibrous membrane display single mechanism of burst like release within 3.5 days and 2.5 days, respectively. The Young's modulus, tensile strength and toughness of TCH/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-COOH/PLA nanofibers are increased by 191%, 150% and 223%, respectively, compared with those of plain PLA electrospun nanofibers. Most importantly, TCH/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-COOH/PLA nanofibrous membrane exhibited significantly stronger antibacterial activities against 〈em〉E. coli〈/em〉 and 〈em〉S. aureus〈/em〉 compared to TCH/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-COOH and TCH/PLA nanofibrous membrane. The improved mechanical performance and sustained drug release behavior on TCH/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-COOH/PLA pave the way for the emerging applications in drug delivery and tissue engineering.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718310033-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Zeinab Barkat Rezaei, Saadat Rastegarzadeh, Alireza Kiasat〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A simple and sensitive sensor has been successfully developed for fast monitoring of azathioprine (AZA) by combining valuable properties of electrospun poly (vinyl alcohol)/chitosan (PVA/CS) nanofibers and surface plasmon resonance of silver nanoparticles (AgNPs) as a smart probe. Attachment of silver ions onto the surface of PVA/CS nanofibers via anchoring with free amino groups in the chitosan framework, and then reducing by ascorbic acid resulting in the formation of decorated AgNPs onto the surface of nanofibers. The presence of AZA during reduction process leads to a decrease in the formation of AgNPs onto the surface, consequently decreasing plasmon resonance intensity of nanoparticles. This change is utilized as a means to create an environmental friendly hybrid probe for the fast and careful detection of AZA. Developed plasmonic nanofibers exhibit a linear response for AZA concentration in the range of 0.14–2.88 μM with the detection limit of 0.09 μM. The relative standard deviation corresponding to eight replicate determinations of 0.86 μM and 2.88 μM of AZA was 1.93 and 2.70%, respectively. Suggested method was effectively applied for the accurate determination of AZA in tablet formulations and human serum samples.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311245-ga1.jpg" width="465" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Qianqian Chen, Yachao Zhu, Maoxin Wang, Gaihuan Ren, Qian Liu, Zhenghe Xu, Dejun Sun〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Surfactants are widely used to reduce the viscosity of heavy oil by emulsification, but emulsification of an extra-heavy oil is difficult and does not even occur in some cases. A diluent is effective in reducing the viscosity of extra-heavy oil, but substantial volumes are required. In this work, we combined the advantages of a surfactant solution and a diluent in the form of emulsions to emulsify extra-heavy oil. The toluene/water (T/W) emulsion was prepared with mixed (AES-DOA) surfactants formed from an anionic surfactant (AES, alkyl polyoxyethylene ether sodium sulfate) and a gemini-like surfactant (DOA, prepared by mixing oleic acid and Jeffamine D 230). Compared with using toluene or AES-DOA surfactant solution alone to achieve the desired extra-heavy oil viscosity (30 ± 10 mPa·s), the T/W emulsion decreased toluene and surfactant dosage from 56 to 3 wt% and from 12 to 2 mmol/L, respectively. The effect of toluene and AES-DOA mixed surfactant on emulsification was analyzed by measuring the viscosity of the resultant extra-heavy oil emulsions. The results suggest that the addition of toluene reduced the viscosity of extra-heavy oil (dispersed phase) and accordingly contributed to emulsify extra-heavy oil. The synergistic effect of the AES-DOA mixed surfactants was evaluated by measuring the interfacial tension and calculating interaction parameters (β〈sub〉m〈/sub〉) of the mixed surfactants formed at different AES mole fractions. When the mole fraction of AES was 0.6 in the mixture, the mixed surfactant possessed the highest interfacial activity and the largest negative β〈sub〉m〈/sub〉, confirming the strongest synergistic effect. As a result, the best emulsification efficiency was achieved at this mole fraction. Increasing toluene content and AES-DOA mixed surfactant concentration was found to increase the emulsion stability against coalescence. The results from this study demonstrate that T/W emulsions prepared using the AES-DOA mixed surfactants can overcome the difficulties in emulsifying the highly viscous extra-heavy oil.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718313785-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Tae Woo Kwon, Joonkyung Jang, Matthew Stanley Ambrosia, Man Yeong Ha〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Using all-atom molecular dynamics simulation, we investigated the wetting behavior of a water droplet on a surface texturized with nanoscale pillars. We studied the surfaces with nonhierarchical and hierarchical roughnesses by systematically varying the pillar height and the characteristic surface energy. A surface decorated with a hierarchical roughness showed an enhanced hydrophobicity in that the droplet on such a surface prefers the Cassie-Baxter state over the Wenzel state. A hierarchical roughness also gave an enhanced contact angle of a droplet. Even a hydrophilic surface (contact angle is 〈 90°) turned hydrophobic (contact angle 〉 90°) with a hierarchical roughness on it. We show the adhesion energy of a droplet to its underlying surface is correlated with the contact angle and therefore is a fundamental measure of the wettability of the surface.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311610-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Shiju Xu, Xueqin An〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel injectable liposome-hydrogels was prepared by combined methods of thin-film evaporation and supercritical carbon dioxide technique (TE-scCO〈sub〉2〈/sub〉) for drug delivery of tissue regeneration. The liposome-hydrogels with thermosensitive is colloidal sol at room temperature, but it is gel at body temperature. Therefore, the thermosensitive liposome-hydrogels can get into the target area by injecting process at room temperature, and it will convert to gel at body temperature. In curcumin liposome-hydrogels (Cur-Lps-H), curcumin (Cur) as model drug was loaded in liposomes and the liposome was embedded in three-dimensional porous chitosan/β-glycerophosphate hydrogel. The microstructure of Cur-Lps-H was studied by using pyrene and 1,6-diphenyl-1,3,5-hexatriene (DPH) as fluorescent probes, and it was found that Cur was entrapped in bilayer of liposomes and its saturated concentration in bilayer of liposomes was about 0.012 (mass ratio of Cur to lecithin). The Cur-Lps-H prepared by TE-scCO〈sub〉2〈/sub〉 method had higher entrapment efficiency and better stability in comparasion with that prepared by thin film hydration (FH). Moreover, the Cur-Lps-H possessed obviously sustained-release effect (extend to 12 days) in vitro, which was longer than other drug delivery system. Therefore injectable liposome-hydrogels is a potential drug delivery system.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718310884-ga1.jpg" width="297" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Yahui Lyu, Chenglin Gu, Xiliang Fan, Jiaping Tao, Xue Yao, Caili Dai, Guang Zhao〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The interfacial phenomena reflected by the thickness of oil films and the stability of oil-in-water emulsions were observed in the soft heterogeneous combination (SHC) flooding process, which were closely linked with the oil recovery. In this work, the effects of tetradecyl hydroxyl sulfo betaine (THSB) concentration and dispersed particle gel (DPG) concentration on the interfacial rheology were investigated; the adsorption performance at different temperatures, salinities and aging times were also systematically evaluated to determine the impact of external factors. The results show that three interactions appeared between the surfactant molecules and DPG particles. The adsorption process presents four stages. At a low THSB concentration and low DPG concentration, some DPG particles can adsorb on the interface together with the surfactant molecules, which markedly increase the adsorption film strength. When the THSB concentration increases, the surfactant molecules tend to interact with each other and aggregates of the surfactant molecules with DPG particles also appear, thereby damaging the compact film structure. As DPG particles are continuously added, the aggregates between particles enhance the strength of the adsorption film. Additionally, interfacial properties were maintained at high-temperatures, high-salinities and long aging times, which indicates the promising application of the SHC flooding system in reservoirs.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718310434-ga1.jpg" width="240" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Julián J. Narbon, Cristina Moreno-Díaz, José Manuel Arenas〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The mechanisms by which adhesion occurs are known. In all cases, the search for an adequate surface condition is decisive in achieving a good adhesion. For this reason, the researches usually work on modifying the surface roughness or improving the thermodynamic characteristics of the surface. The objective on this work is to analyse influence of different attack types (chemical, mechanic, with laser …) which are used to improve surface finish, roughness and surface energy. We have analysed the effects that have produced in the contact angle, measuring the surface energy by the Zisman method. The results revealed that the method of attack has more influence on the value of surface energy than the values of roughness obtained, which can make rethink the type of surface treatment to improve adhesion.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571831001X-ga1.jpg" width="351" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Jian-Rong Li, Feng-Kang Wang, Hang Xiao, Lei Xu, Ming-Lai Fu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The layered chalcogenide KMS-1 was modified by La/Ca/Mg via a simple ion exchange process for the removal of phosphate from water. La-modified KMS-1 (KLa), Ca-modified KMS-1 (KCa) and Mg-modified KMS-1 (KMg) were comparatively characterized using X-ray diffraction, BET surface area, zeta potential and scanning electron microscopy, respectively. It was found that the adsorption capacity of KLa was higher than that of KCa and KMg. Kinetic data were fitted well to a pseudo-second-order kinetic model. Solution pH slightly affected the removal of phosphate by KLa in the range of 3–9. Compared to KCa and KMg, KLa exhibited a high selectivity to phosphate in the presence of coexisting anion such as SO〈sub〉4〈/sub〉〈sup〉2〈/sup〉ˉ, CO〈sub〉3〈/sub〉〈sup〉2〈/sup〉ˉ, Fˉ, Clˉ or NO〈sub〉3〈/sub〉ˉ with same molar concentration. Importantly, KLa had the capacity to remove phosphate effectively from real sewage. Moreover, the used KLa could be successfully regenerated by KOH and HCl solution. Zeta potential, scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis indicated that the precipitation, surface deposition and complexation were responsible for the mechanism of the phosphate removal by KLa.〈/p〉〈/div〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉 〈p〉Schematic illustration of KLa preparation and adsorption mechanism of KLa〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718307246-ga1.jpg" width="315" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): A.W. Ritchie, H.J. Cox, S.N. Barrientos-Palomo, G.J. Sharples, J.P.S. Badyal〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Bioinspired polymer–nanoparticle–fluorosurfactant complex composite coatings are shown to display fast-switching oleophobic–hydrophilic properties. The large switching parameters (difference between the equilibrium oil and water static contact angles) are attributed to nanoparticle enhanced surface roughening (leading to improvement in hydrophilicity and oleophobicity for optimum nanoparticle loadings). Nanoparticle incorporation also increases hardness of the coatings (durability). Porous substrates coated with these polymer–nanoparticle–fluorosurfactant complex composite coatings are found to readily separate oil–water mixtures under both static and continuous flow as well as displaying antibacterial surface properties against 〈em〉Escherichia coli〈/em〉 (Gram-negative bacteria) and 〈em〉Staphylococcus aureus〈/em〉 (Gram-positive bacteria). A key advantage of this approach for coating substrates is its single-step simplicity. Potential applications include provision of safe drinking water, environmental pollution clean-up, and anti-fogging.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718314122-ga1.jpg" width="463" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Jannis F. Carstens, Jörg Bachmann, Insa Neuweiler〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The DLVO (Derjaguin-Landau-Verwey-Overbeek) approach to predict colloid mobility in porous media is centered on solution ionic strength and physicochemical surface properties of colloids and solid matrix. However, several colloid retention mechanisms are not related to such interfacial properties, but instead to hydraulic features like flow regime and pore structure. We aimed to determine the relative importance of DLVO-related and non-DLVO-related retention mechanisms, which remains poorly understood. For that, we developed a conceptual approach based on previous research on organic matter-coated goethite (OMCG) colloid mobility in quartz sand. OMCG colloid retention by DLVO mechanisms was negligible at 0.0 mM ionic strength. Therefore, any retention at 0.0 mM can be assigned to non-DLVO retention. At increasing ionic strength, the amount of DLVO retention is rising, while the amount of non-DLVO retention is independent from ionic strength and thus remains constant. This allows for a differentiation between the two types of retention mechanisms. To test this conceptual approach, we conducted OMCG colloid breakthrough experiments at varying interfacial conditions (ionic strength: 0.0–5.53 mM) and hydraulic conditions (flow rate: 0.11 – 5.02 cm min〈sup〉−1〈/sup〉). From sessile drop contact angles and zeta potentials, DLVO and extended DLVO (XDLVO) interactions including Lewis acid-base interactions were approximated. The results show that colloid retention was almost exclusively related to DLVO retention mechanisms, while retention by hydraulic factors was practically irrelevant. We conclude that our conceptual approach can be applied to determine the relative importance of colloid retention caused by DLVO and non-DLVO mechanisms for further colloid-solid matrix systems.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718313141-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Krishnayan Haldar, Sudipto Chakraborty〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉An instantaneous chemical reaction and solidification have been experimentally explored during sodium alginate drop impact on calcium chloride liquid pool through a high-speed imaging system. Here, different concentrations of sodium alginate are used to study the effect on gelation process. As soon as the alginate drop touches the calcium chloride pool, a crosslinking polymerization reaction starts under the liquid pool surface. The consequence of crosslinking is rapid formation of calcium alginate gel which denotes instantaneous freezing of liquid drop. The drop impact solidification immediately results in the formation of a strong gel layer in front of it which is having significant role in spherical shape recovery. This layer formation is favoured by increasing sodium alginate concentration in the drop and thus crater growth is hindered also. The initial reaction time which is determined as soon as the drop touches the surface, is found to be dependent on the drop kinetic energy. However, the drop gelation time reduces with drop concentration and it controls the final shape and morphology of gel. Such reduction in gelation time is inferred from the enhanced rate of crosslinking reaction. The motion of liquid drop through liquid pool while interacting with the surroundings influences the drag around the spherical drop. The shape evolution in the solidifying gel is governed by the dynamics between the fluid drag and chemical reaction. The morphology of the gel surface has also been studied and its roughness variation has been measured from fractal box counting method.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571830880X-ga1.jpg" width="317" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Binfei Li, Haifeng Li, Aiqing Cao, Fei Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Foam has been widely used for profile control, water plugging, and gas channeling control in enhanced oil recovery (EOR). Because of absorption, the surfactant concentration in foam decreases along the flow direction. In this study, the effects of surfactant concentration on the foam texture, foam seepage characteristics, and gas saturation were evaluated by core-flow experiments using a high-pressure visualization device. The results show that the surface tension of gas and liquid decreases, the flow resistance in core increases, and the foam takes a longer time to reach stability with the increase in concentration of foaming agent. The blocking capability of foam in porous media is closely related to foam texture. With the increase in surfactant concentration, the average diameter of bubbles in porous media decreases, and the bubbles are more uniform. Moreover, the diameter of bubbles is closer to the average pore diameter of core. Clearly, the diameter matching degree of the maximum distribution frequency of bubbles and the average pore diameter of core increase. Therefore, the blocking capability of foam becomes stronger. With the increase in surfactant concentration, the proportion of trapped gas in porous media increases, the gas saturation in core increases, and the flow resistance of foam increases. However, when the surfactant concentration reaches the critical value, the increasing amplitude of gas saturation decreases. Under an injected foam quality of 50%, the gas saturation is more than 80%. The research results can help to analyze the change along the channel of foam flow in formation and are of great significance to improve the effect of foam application.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718313876-ga1.jpg" width="238" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Abhijeet Kumar, Alexandra Trambitas, Jörg Peggau, Verena Dahl, Joachim Venzmer, Tatiana Gambaryan-Roisman, Jochen Kleinen〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Organomodified silicones (OMS), which conventionally find use in textile finishing processes, have recently become a very interesting prospect in the field of fabric softeners. Here, we present OMS-based fabric softener formulations in the form of classical emulsion (droplet size ≈0.1 μm – 10 μm) and microemulsions (droplet size ≈5 nm–50 nm) using nonionic surfactants (NIS) as emulsifier. Streaming potential measurements are used to obtain a measure of droplet surface charge, and it was found to be related to the ratio of masses of OMS and NIS present in the formulations. In this work, it is investigated how the performance of these formulations is influenced by properties such as droplet size and streaming potential. Panel tests were carried out to evaluate the sensory properties of fabric treated by these formulations, and they reveal that the classical emulsion performs better than the microemulsions. For the microemulsions, it is found that softening performance increases with streaming potential. The observed trends in softening performance are explained by considering the difference in location or penetration of softening actives on or into fabric. Two different experimental approaches are implemented to gain insights into the underlying phenomena. In the first approach, batch deposition experiments are carried out to characterize OMS deposition on fabric. In the second approach, a chromatographic technique is used to compare the deposition kinetics of different formulations. The findings of the experiments provide insights into the reasons underlying the contrasting softening performance. The final results are discussed with respect to existing literature.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718312408-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 561〈/p〉 〈p〉Author(s): Dafna Meshulam Pascoviche, Neta Goldstein, Ayelet Fishman, Uri Lesmes〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Emulsions are complex mixtures of immiscible liquids that are widely spread in foods and considered as natural, efficient and cost effective tools to deliver lipophilic bioactives to the consumer. Many recent studies seek to elucidate the principles for formulating emulsions with novel bioactive ingredients, such as bovine lactoferrin or bioactive lipids, towards enhanced and extended emulsion functionality. This research evaluated the effects of droplet lipid unsaturation degree on emulsion properties, stability and susceptibility to intestinal lipolysis. For this purpose, emulsions were produced via high pressure homogenization using extra virgin olive oil (EVOO) rich in 18:1n9 oleic acid, hemp seed oil (HSO) rich in 18:2n6 linoleic acid and pomegranate seed oil (PSO) rich in 18:3n5 conjugated linolenic acids (CLnA). Droplet fatty acid composition was altered using glyceryl trioleate (TOLN) doping at varying concentrations (1%, 2%, 5% and 10% [w/w]) and found to temper emulsion stability, droplet size, droplet size distribution spans. In respect to intestinal lipolysis, TOLN did not affect EVOO lipolysis, had mild impact on HSO lipolysis and markedly accelerated and enhanced the lipolysis of PSO. Fatty acid profiling of intestinal digesta indicated the preferential liberation of saturated, then monounsaturated and lastly polyunsaturated fatty acids from the various lipid droplets. Overall, the results presented herein show a new possibility for smart design of emulsions with sustained and controlled release of unsaturated fatty acids in the human gut.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718307684-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Zhen Yang, Xianping Liu, Yanling Tian〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Inspired by the famous “lotus effect”, we have fabricated the super-hydrophobic surfaces with nickel film on copper substrates using a one-step electrodeposition method. By adjusting processing time, water contact angle of as-prepared surfaces can reach as high as 160.3 ± 1.5° with small rolling angle of 3.0 ± 0.5°, showing excellent super-hydrophobicity. After the deposition of nickel coating, the pristine copper surfaces became much rough with packed cauliflower-/thorn-like clusters. This unique surface texture contributed to trapping large amount of air and forming the air cushion underneath the water droplet, which can prevent the liquids contacting the copper substrate. The examination of surface chemical compositions implied that the deposited super-hydrophobic coating consisted of nickel crystals and nickel myristate. In this research, the formation mechanism of the electrodeposited super-hydrophobicity was extensively explained based on the analyses of surface texture and surface chemistry. Moreover, the corrosion resistance of the as-fabricated super-hydrophobic surface was estimated by the potentiodynamic polarization tests as well as the electrochemical impedance spectroscopy (EIS) measurements. The results demonstrate that the super-hydrophobic nickel coating showed excellent corrosion inhibition in simulated seawater solution. The existence of the super-hydrophobic coating could be regarded as a barrier and thus provide a perfect air-liquid interface that inhibits the penetration of the corrosive ions. This facile and effective method of electrodeposition process offers a promising approach for mass production of super-hydrophobic surfaces on various metals.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718307714-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Yijun Fu, Qi An, Ruiyan Ni, Yu Zhang, Yonggui Li, Huizhen Ke〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Polyaniline-encapsulated carbon/copper composite nanofibers (PANI/CuCNFs) were synthesized by a facile and efficient method combining electrospinning and in-situ polymerization, which were further applied to the laccase (Lac) based biosensor for polyphenol pollutant detection. The morphology and composition of the fabricated nanocomposite were investigated by a series of advanced characterization techniques. The electrochemical behaviour of the novel biosensor was studied through cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronoamperometry. Results showed that the addition of PANI/CuCNFs apparently improved the electrocatalytic properties of the Lac-based biosensor towards hydroquinone. The constructed biosensor possessed a high sensitivity (41.65 μA mM〈sup〉−1〈/sup〉), a low detection limit (0.24 μM), and a wide linear range from 500 nM to 110 μM, as well as satisfied selectivity, reproducibility and repeatability. Moreover, the biosensor gave a successful application in hydroquinone measurement of river water. This work suggested that the Lac biosensor modified by PANI/CuCNFs has a great potential in the application of phenolic pollutants detection.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Polyaniline-encapsulated carbon/copper composite nanofibers (PANI/CuCNFs) were prepared for the first time by a facile and efficient method combining electrospinning and in-situ polymerization. A novel biosensor was constructed based on a composite of PANI/CuCNFs, Laccase, and Nafion. The novel biosensor showed excellent electrochemical properties and highly efficient catalysis towards hydroquinone.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718307581-ga1.jpg" width="219" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Si Sun, Qian-Ru Xiao, Xuan Zhou, Ying-Ying Wei, Lin Shi, Yong Jiang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, a novel bio-based environment-friendly membrane for oil-water separation is made via a facile method of coating agarose hydrogel on fabrics. The membrane can separate a range of different oil-water mixtures with 〉95% separation efficiency, indicating its high oil-water separation ability. Moreover, the membrane can be easily cleaned and maintain its high oil-water separation performance after 10 separation cycles. As the membrane is made of agarose hydrogel and fabrics, it is biocompatible and eco-friendly. Furthermore, since both the agarose and fabrics are commercially available, the facile preparation process can be scaled up for large-scale production of these oil-water separation membranes with low cost, which is of great benefit in solving the oily wastewater problem.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718310902-ga1.jpg" width="262" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Chi Jiang, Weiqu Liu, Maiping Yang, Chunhua Liu, Sha He, Yankun Xie, Zhengfang Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We present a facile and an inexpensive approach to prepare robust fluorine-free self-cleaning cotton textiles by surface modification with anatase TiO〈sub〉2〈/sub〉 sol and polydimethylsiloxane (PDMS) using a simple dip-coating method. The synergetic effect of the anatase TiO〈sub〉2〈/sub〉 particles and PDMS was critical and essential for obtaining a superhydrophobic coating with photocatalytic activity and UV durability. The coated cotton textiles not merely exhibited desirable superhydrophobic property with a water contact angle (WCA) of 153.8°, but also performed the considerable photocatalytic activity by the decomposition of oil red O under UV exposure. Importantly, the as-obtained self-cleaning cotton textiles were stable under various harsh conditions such as acidic, alkaline, corrosive organic solutions, and laundering. Moreover, the coated cotton textiles could also maintain its superhydrophobicity when exposed to long-term UV irradiation, displaying its excellent UV resistance. Therefore, this simple preparation approach can be regarded as a promising way to construct self-cleaning surfaces for scale up production.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718308549-ga1.jpg" width="244" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): Léa Guérin, Christine Frances, Alain Liné, Carole Coufort-Saudejaud〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Flocculation experiments were performed in a Taylor-Couette reactor in turbulent conditions characterized by the mean shear rate. A sequenced hydrodynamic protocol was applied which consists in low and high shear rates steps allowing to promote respectively aggregation and breakage processes. The particle size distribution and the 3D fractal dimension were determined on line by laser diffraction while morphological parameters were characterized off line using an automated microscope coupled with image processing. After a first aggregation-breakage cycle, the flocs formed by charge neutralization have smaller sizes than during the first aggregation step when the main aggregation mechanism is the charge neutralization whereas coarser but more resistant aggregates can be produced by bridging mechanism. During the flocculation process, high shear rates calibrate the flocs, creating small flocs having a size close to the Kolmogorov microscale. These small flocs serve as bricks to form larger flocs when lower shear rates are applied and a full reproducibility is observed after one or two cycles of the sequence depending on the aggregation mechanism. A clear correspondence was put in evidence between the shear rate conditions and the volume base mean size or fractal dimension of flocs. The morphological fractal dimension, as well as the fractal dimension derived from laser measurements, are in good agreement with the mean trend of the morphological data but cannot represent the whole diversity of floc sizes and shapes. The 3D surface base area and perimeter distributions appear as a promising tool allowing a deeper analysis of the impact of physico-chemical and shear conditions on aggregate properties during a flocculation process.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718313153-ga1.jpg" width="461" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Changyao Liu, Yuzhao Wang, Chenxing Chai, Sana Ullah, Guiju Zhang, Baocai Xu, Hongqin Liu, Li Zhao〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The development of amino acid surfactants which are considered to be biodegradable and less toxic than traditional surfactants has been a subject of growing interests among chemists for the past 20 years. Within this category, 〈em〉N〈/em〉-acyl amino acid surfactants are popular due to their excellent interfacial properties and antimicrobial activities. In the present work, six new 〈em〉N〈/em〉-acyl amino acid surfactants were synthesized using vegetable oils (castor oil and cottonseed oil) and amino acids (glycine, alanine, and serine). Surface active properties of these surfactants were investigated. With the amide bonds acting as hydrogen bond donors and acceptors, globular and tubular vesicles were observed in the aqueous solutions of some prepared surfactants. The results indicated that hydroxyl groups on the hydrophobic tails for castor oil derivatives were associated with spherical vesicles formation, whereas serine residues bearing hydroxyl groups may be associated with the tubular vesicles.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311142-ga1.jpg" width="461" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Maria C. Sportelli, Maurizio Clemente, Margherita Izzi, Annalisa Volpe, Antonio Ancona, Rosaria A. Picca, Gerardo Palazzo, Nicola Cioffi〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Silver nanoparticles synthesized using laser ablation synthesis in isopropanol, in absence of additional capping agents, were found to be stable with respect to both aggregation and silver oxidation over several months. The rationale for this extreme stability of metal nanoparticles suspended in organic solvents was challenging. On the basis of theoretical considerations and basic experiments it is proposed that the stabilization of silver nanoparticles involves the formation of an organic coating generated by the interaction of isopropanol molecules with the pulsed, high-energy laser beam. This coating prevents, on the one hand, any chemical reaction on colloidal nanoparticles (e.g. silver oxidation); on the other hand, the presence of the organic shell with a nature akin to that of the organic solvent led to weaker Van der Walls interactions between approaching nanoparticles enabling a larger stability than for naked metallic nanoparticles.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311233-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Chengxin Hu, Ran An, Linglin Han, Xiangdong Wang, Yingling Shi, Rong Ran〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As a fascinating soft material, hydrogel has attracted tremendous attention due to its potential for applications in smart structures and biomedical engineering. However, common hydrogels with low mechanical properties cannot be suitable for rough environments with strong external loads. This study reports a general and facile strategy to fabricate tough and high energy dissipation double cross-linked (DC) hydrogels which contain two kinds of physical interactions - hydrophobic association and metal ions coordination. The double physically cross-linked gels were prepared by a simple, three-step method: synthesis, immersion, and rearrangement. During the immersion procedure, we were surprised to find the core-shell like structure which was caused by the Fe〈sup〉3+〈/sup〉 uneven diffusion. The four typical kinds of the core-shell structure were further investigated, and a comprehensive hypothesis mechanism about the soaking and rearrangement was suggested. Consequently, based on the results of above homogeneous double physically cross-linked gels with high strength (9.8–12.4 MPa) and good energy dissipation (21.3–24.07 MJ/m〈sup〉3〈/sup〉) were obtained by finding suitable reagent concentration and ion rearrangement processes. This fabrication process enhances our ability to guide the design of next-generation tough hydrogels.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718310847-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 30 May 2017〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Johanna Milsmann, Kathleen Oehlke, Ralf Greiner, Anja Steffen-Heins〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The release and partitioning of encapsulated compounds from solid lipid nanoparticles (SLN) to other matrix constituents was investigated in o/w emulsions stabilized by different surfactants (CTAB, SDS, Tween 20) by confocal laser scanning microscopy (CLSM) and electron paramagnetic resonance spectroscopy (EPR) spectroscopy. CLSM images revealed that the encapsulated probe Coumarin 6 (C6) was located in the oil droplets after SLN were mixed with the different emulsions. The EPR spin probe TEMPOL‐benzoate (TB) showed different dynamics as a function of its specific solubilization sites in SLN. Four different populations of the spin probe could be separated giving the smallest population in the aqueous environment and the major population at the SLN interface. Two further populations were associated with differently crystalized lipid environments. This implies that both loosely structured regions with α- and β’-polymorphs and environments of β-polymorphs are present in SLN. In separated model emulsion systems, a prolonged release of TB from SLN was evident which predominately originated from the SLN interface. The released TB partitioned into the oil phase (25%) and into the o/w interface (30–45%), regardless of the presence or absence of additional surfactant micelles. Hence, these edible SLN may be used as delivery system for bioactive compounds in food emulsions with low impact of the surfactant used to stabilize the emulsion. The partial redistribution of the encapsulated compounds should be taken into account, but can also offer benefits when a prolonged release of lipophilic additives is desired.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775717304946-fx1.jpg" width="315" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Isabelle Simonsson, Christian Sögaard, Mark Rambaran, Zareen Abbas〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Based on extensive experimental investigations on many different oxide nanoparticles, it is now a well-established view that the counter-ions exhibit ion specific effects due to their high charge density and strong interaction with oppositively charged surfaces. On the other hand, studies regarding co-ion effects are scarcely reported in the literature. In this study we have measured the surface charge densities and gel-times of silica nanoparticles in a number of salts which have the same counter-ions but different co-ions, i.e. anions in this case. Gel-times were measured in LiCl, NaCl, NaNO〈sub〉3〈/sub〉, NaClO〈sub〉4〈/sub〉, NaClO〈sub〉3〈/sub〉 and Na〈sub〉2〈/sub〉SO〈sub〉4〈/sub〉 as well as in KCl, KNO〈sub〉3〈/sub〉, and K〈sub〉2〈/sub〉SO〈sub〉4〈/sub〉. We have seen clear correlations between the gel-times and the extent of ion pairing in the solutions; salts that have strong ion pairing exhibit longer gel-times than salts having highly dissociated ions. To better understand the mechanisms at work we have determined the surface charging of silica nanoparticles in these salt solutions and we have observed that the surface charging behavior of silica nanoparticles follows the trends seen in the gel-time studies. From our gel-time determinations and potentiometric measurements we can claim that there is a clear co-ion effect on the gelling and surface charging of silica nanoparticles.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718307118-ga1.jpg" width="486" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Julie Wolanin, Loïc Barre, Christine Dalmazzone, Daniela Bauer〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The structure of vesicles formed by anionic surfactant sodium bis(2-ethylhexyl) sulfosuccinate (AOT) in brine solution (1.5 wt% NaCl) at 20 °C, in the diluted region of the phase diagram, has been characterized by cryogenic transmission electron microscopy (cryo-TEM) and the combination of three scattering techniques (Small Angle X-ray Scattering (SAXS), Dynamic Light Scattering (DLS) and Multi-angle light scattering (MALS)). Results show a polydisperse vesicle size system. The distribution is mainly composed of small vesicles (14 nm diameter) and there is no micelles in solution. The determination of the form factor indicates the presence of only spherical vesicles (no other morphologies, such as tubular vesicles, were observed). The bilayer structure of the vesicles was characterized by SAXS and the membrane thickness measured at 2.7 nm. This thickness is shorter than twice the AOT molecule extended length indicating a non-negligible interpenetration of the hydrophobic tails.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311488-ga1.jpg" width="340" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 560〈/p〉 〈p〉Author(s): A. Reznickova, N. Slavikova, Z. Kolska, K. Kolarova, T. Belinova, M. Hubalek Kalbacova, M. Cieslar, V. Svorcik〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Designing safe nanomaterials is nowadays a critical issue. A way to prepare PEGylated Au NPs by sputtering of Au into pure (PEG), thiol (PEG-SH) and amine terminated polyethylene glycols (PEG-NH〈sub〉2〈/sub〉) was explored. Structural characterizations, aging and thermal stability were performed using transmission electron microscope (TEM/HRTEM) and UV–vis spectroscopy. By TEM we observed that spherical Au NPs were successfully prepared with average diameter of 1.5–5.9 nm. HRTEM revealed that a majority of them is rather of a round or irregular shape with a frequent multiple twinning. Dynamic light scattering as well as TEM confirmed that Au NPs have monodal size distribution. According to atomic absorption spectroscopy, concentration of gold increases with sputtering time and does not change with aging time. PEG-SH exhibited loss of SPR absorption band in UV–vis spectrum because of the small NP size (1.5 nm). PEG and PEG-NH〈sub〉2〈/sub〉 showed good thermal and aging stability. No significant antibacterial effect of any type of the studied Au NPs has been discovered. Cytotoxic effect on osteoblasts was determined only with the highest concentration of Au NP with PEG and PEG-NH〈sub〉2〈/sub〉 stabilization. Au NPs stabilized by PEG-SH showed the overall optimal physical and biological properties for drug delivery applications.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718312299-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Lu Xu, Lei Feng, Shuli Dong, Jingcheng Hao, Qun Yu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We report the fabrication of magnetic carbon nanotubes (MCNTs) through one-step modification with a paramagnetic cationic surfactant for migration of DNA and proteins. DNA and proteins can effectively bind to the surfactant-coated MCNTs through electrostatic interaction. Targeted transport platform of DNA and proteins as delivery agents can be constructed upon application of an external magnetic field. The native conformation of these biomacromolecules can be suitably maintained without denaturation during the migration process. We expect it will find MCNTs potential applications in gene delivery, gene transfection, protein delivery and separation.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718310811-ga1.jpg" width="299" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 559〈/p〉 〈p〉Author(s): Xin Jin, Ning Ren, Xinting Wu, Rui Chen, Xinyuan Zhu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Preparation of small size core-shell polymer nanoparticles has significant applications in photonic crystal materials and drug delivery systems. Although core-shell nanoparticles could be easily prepared by seeded emulsion polymerization, their size was generally larger than that of seeds, which limited their further applications in some areas. In this work, a new method was utilized to prepare small size core-shell polymer nanoparticles. In detail, poly(N-isopropylacrylamide) ionic microgels (encoded as PNI microgels) with controllable diameter were firstly prepared and then used as seeds in seeded emulsion polymerization of styrene. After polymerization, core-shell nanoparticles which were smaller in size than that of seeds were obtained. In order to reveal this abnormal phenomenon, the inner structure, components, element distribution, thermo-sensitivity and deformability of the obtained nanoparticles were characterized by TEM, FTIR, DSC, EDS, DLS and AFM. It was found that the core composed of polystyrene and the shell composed of PNI microgels in the core-shell nanoparticles. The detailed formation process was then studied systematically. It was found that polystyrene nanoparticles formed within PNI microgels and peeled off from the seeds when they were large enough. Considering the weak ionic interaction of PNI microgels, mechanism for this phenomenon was proposed. Factors, such as initiator type, microgel type, cross-linking degree and stirring speed, also had significant effects on the formation of core-shell nanoparticles.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718311361-ga1.jpg" width="217" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉