ALBERT

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 578〈/p〉 〈p〉Author(s): Yadan Guo, Chenxi Li, Yiqin Guo, Xuegang Wang, Xiaomeng Li〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Graphitic carbon nitride (g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉) is a new type of nonmetal polymeric semiconductor photocatalyst for removal of pollutants. To overcome the low BET surface and the low electron–hole recombination rate of the g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 photocatalysts, we successfully synthesized g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/Na-bentonite composites using an ultrasonic-assisted method. The XRD showed that the composite was composed of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 and Na-bentonite. The analyses of TEM and XPS indicated that graphite carbon nitride was successfully intercalated on Na-bentonite via the ultrasonic-assisted strategy, and the g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/Na-bentonite nanocomposites presented remarkable light absorption capacities and mesoporous structure observed by UV–vis DRS and BET method. In addition, the as-prepared composites can be used for the photocatalytic removal of single RhB or Cr(VI), and the efficiencies of the Cr(VI) reduction are increased from 53.2% to 88.6% in RhB/Cr(VI) mix-system. Superior stability and high efficiencies of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/Na-bentonite composites were also exhibited for up to 4 cycles. The photocatalytic enhancement was due to the strong adsorption and the higher charge separation efficiency of as-prepared g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/Na-bentonite composites.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719306065-ga1.jpg" width="219" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 578〈/p〉 〈p〉Author(s): Lifeng Chen, Zhen Qian, Liang Li, Meilong Fu, Hui Zhao, Lipei Fu, Gang Li〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Water production is getting worse along with the continuous water injection in the reservoir with fracture, but common hydrogels cannot be successfully applied for water shutoff due to its poor resident ability in fracture. In this work, an interpenetrating network hydrogel has been developed innovatively by polyvinyl alcohol (PVA) fiber and common polyacrylamide (PAM) hydrogel. Plugging ability, long-term thermal stability and the interaction between PVA fiber and hydrogel were detailedly studied. Results show that PVA fiber is beneficial to the stability of the PAM hydrogel, and the syneresis rate can be decreased from 30% to 3% on the 120〈sup〉th〈/sup〉 day. PVA fiber accelerates the hydrogel gelation, and the high concentration of fiber leads to good hydrogel strength. PVA fiber increases the amount of the bound water in hydrogel, leading the hydrophilcity increase of hydrogel. An interpenetrating network is formed on the micrometer level, resulting from the three-group crosslinking among polymer, cross-linker and fiber. Compared with common PAM hydrogel, the interpenetrating network hydrogel has better water shutoff effect and EOR performance. Core flow experiment and micromodel test show that the interpenetrating network hydrogel forms an effective bridge in fracture, and it is hard to be moved due to the water washing. The introduction of fiber to hydrogel is an innovative research, which not only improves the water shutoff effect of hydrogel in fracture, but also provides reference to increase the performance of drilling fluid, fracturing solution and EOR polymer utilized in petroleum engineering.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Micropresentation of synergistic effect of PVA fiber on PAM solution (A, B) and hydrogel (C, D).〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719305928-ga1.jpg" width="252" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 578〈/p〉 〈p〉Author(s): Krzysztof Kolman, Zareen Abbas〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Molecular dynamics (MD) simulations provide molecular level information about the interaction of organic molecules with the solid surfaces. There has been much development of this method to simulate the interaction of organic molecules with neutral surfaces but relatively less information is available regarding the interactions with charged surfaces. In this study we have developed MD model for the charged silica surface and have investigated the interactions of different benzoic acid derivatives with the charged silica surface in pure and saline water at acidic, neutral and basic pH. The investigated molecules were 2,3-dihydroxybenzoic acid (23DHBA), 3,4-dihydroxybenzoic acid (34DHBA), 1,2,4-benzenetricarboxylic acid (BTCA) and phthalic acid (PHTHA). To simplify the analysis of results, three different simulation systems were considered. Clustering simulations showed how molecules aggregate in solution, pulling simulations provided quantitate information regarding the interactions of single molecule with the silica surface, whereas adsorption simulations focused on the adsorption of multiple molecules on the surface. In general, at pH 2–3, all investigated molecules were clustering and were attracted towards the surface. At pH 7, due to arising electrostatic repulsion, the interactions became weaker which prevented 23DHBA, 34DHBA and BTCA from clustering, however, they continued to adsorb on the silica surface. The adsorption of 23DHBA and 34DHBA decreased significantly at pH 9–10 due to electrostatic repulsion between the molecules and charged silica surface, while BTCA adsorbed slightly stronger due to interactions with ions close to the surface. PHTHA molecules behaved differently by clustering stronger and adsorbing weaker at higher pH. The results of MD simulations presented in this work by using pulling and adsorption approaches provide possibility to compare the results with experimental data.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719301748-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 578〈/p〉 〈p〉Author(s): José G. Parra, Héctor Domínguez, Yosslen Aray, Peter Iza, Ximena Zarate, Eduardo Schott〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Structural characteristics, interfacial distribution and molecular interactions of the components of the CO〈sub〉2〈/sub〉(gas)/SDS/water/SDS/CO〈sub〉2〈/sub〉(gas) systems as a function of the CO〈sub〉2〈/sub〉(gas)/water interface coverage by the SDS surfactant to different amounts of the CO〈sub〉2〈/sub〉 were studied with molecular dynamics simulations and the NVT ensemble. Initially, the repulsive nonbonding parameter between the water oxygen and CO〈sub〉2〈/sub〉 oxygen was adjusted to improve the prediction of the solvation free energy, solubility of the CO〈sub〉2〈/sub〉 gas in water and the behavior of the CO〈sub〉2〈/sub〉(gas)/SDS/water/SDS/CO〈sub〉2〈/sub〉(gas) systems at molecular level. Our results show that the stability of the studied foams can be improved incrementing of the vapor/water interface coverage with the SDS surfactant and the amount of CO〈sub〉2〈/sub〉 in the system. With the highest interface coverage, the sulfate group has a molecular array more compact at the interface. Furthermore, CO〈sub〉2〈/sub〉 gas have a reduction of the diffusion across of the hydrocarbon chains to the water layer with an increment of the number of CO〈sub〉2〈/sub〉 molecules in the system, indicating a behavior more hydrophobic of the CO〈sub〉2〈/sub〉 gas. The tendencies obtained of the simulations are consistent with the reported experimental results.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719305989-ga1.jpg" width="239" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 578〈/p〉 〈p〉Author(s): M. Jinish Antony, C. Albin Jolly, K. Rohini Das, T.S. Swathy〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We report here the synthesis of polyaniline (PANI) nanomaterials using sodium bis (2-ethylhexyl) sulfosuccinate (AOT) micelles assisted chemical oxidative interfacial polymerization. We have employed two interfaces (chloroform-water and hexane-water) and two oxidizing agents (ammonium persulfate and ferric chloride). The anionic surfactant sodium bis (2-ethylhexyl) sulfosuccinate (AOT) forms normal micelles in aqueous solution and reverse micelles in hydrophobic solvents like hexane or chloroform. The factors influencing the properties and morphologies of polyaniline nanomaterials such as monomer: surfactant ratio, monomer: oxidant ratio, types of interfaces and oxidants used have been studied. Powder X-ray diffraction of the polyaniline nanomaterials have revealed that polyaniline samples were semi-crystalline in nature. Morphology of polyaniline samples studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) have revealed that most of the polyaniline nanomaterials synthesized using ferric chloride possess spherical nature, whereas polyaniline samples synthesized using ammonium persulfate (APS) possess short nanofibers especially at lower aniline/AOT mole ratio in feed (12.5–6.5). The four probe electrical conductivity of the samples were found to be of the order of 1.8 × 10〈sup〉−1〈/sup〉 to 8.6 × 10〈sup〉−1〈/sup〉 S/cm. Thermal stability of the polyaniline samples recorded by thermogravimetric analysis (TGA) have revealed that polyaniline samples were thermally stable up to 275 °C for 10% weight loss. Interfacial polymerization of aniline monomer using reverse micelles of AOT in hexane phase and ammonium persulfate as oxidizing agent in aqueous phase have been proved to be efficient method for the synthesis of short polyaniline nanofibers.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719306090-ga1.jpg" width="316" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 578〈/p〉 〈p〉Author(s): Feng Zhao, Shibin Wang, Xin Shen, Jianchun Guo, Yuxuan Liu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Inhibiting acid-rock reaction rate is an important key in the field of acid fracturing. Based on the acid-rock reaction mechanism and the performance characteristics of surfactant, the surfactant is applied to cover the rock surface for forming an adsorption layer, which can keep H〈sup〉+〈/sup〉 from contacting the surface of rock during acid fracturing. In this paper, a series of cationic Gemini surfactants with different hydrophobic chain length are synthesized (C〈sub〉n〈/sub〉-4-C〈sub〉n〈/sub〉, n = 12, 14, 16).The surface tension, adhesion work, and AFM are used to investigate the effect of hydrophobic chain length and concentration of surfactant on surface activities, adsorption morphology and adsorption capacities. The static acid-rock reaction rate is measured and the surface of the rock plate is digitally characterized by 3D scanning. The results show that Gemini surfactants have the high surface activities. It can be recognized from AFM that as the length of the carbon chain increases, the aggregation of Gemini surfactants on the surface to form micelles becomes more and more obvious, resulting in a decrease in the density and area of the adsorption. However there are few differences for adsorption capacities. Therefore, 12-4-12 can restart H〈sup〉+〈/sup〉 most efficiently. This conclusion is proved by static acid-rock reaction. In addition, H〈sup〉+〈/sup〉 only reacted with the rock from the micro fractures of the adsorption layer formed by 12-4-12, the surface morphology of the rock plate after etching is the best rugged. In conclusion, it is believed that using the Gemini surfactant to form an adsorption layer on the rock surface is a new approach for inhibiting acid rock reaction rate and has great potential in oil field application.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Inhibiting acid-rock reaction rate is an important key in the field of acid fracturing. The morphology of the surfactant on the rock controls the rate between acid and rock. The properties of the different chain length surfactant form different layered structure on the substrate. 12-4-12 can play an efficacious role to adsorb on the rock surface to prevent H〈sup〉+〈/sup〉 from contacting the surface of rock.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719306119-ga1.jpg" width="295" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 578〈/p〉 〈p〉Author(s): Zhao Mu, Jianhao Hua, Sai Kumar Tammina, Yaling Yang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In current investigation, we synthesized a new Cu, N co-doped carbon dots/Ag〈sub〉3〈/sub〉PO〈sub〉4〈/sub〉 (Cu, N-CDs/Ag〈sub〉3〈/sub〉PO〈sub〉4〈/sub〉) nanocomposite by one-step thermolysis and precipitation method. In addition, we evaluated the activity of Ag〈sub〉3〈/sub〉PO〈sub〉4〈/sub〉 and Cu,N-CDs/Ag〈sub〉3〈/sub〉PO〈sub〉4〈/sub〉 nanomaterials in degrading an environmental pollutant called neutral red under visible radiations. Compared to the pure Ag〈sub〉3〈/sub〉PO〈sub〉4〈/sub〉, Cu, N-CDs/Ag〈sub〉3〈/sub〉PO〈sub〉4〈/sub〉 had shown high degradation efficiency by more than 25% and shown good recyclability. The synthesized nanocomposite was characterized by XRD, HRTEM, FT-IR, Raman and XPS techniques. The optical property of Cu, N-CDs/Ag〈sub〉3〈/sub〉PO〈sub〉4〈/sub〉 nanocomposite was examined with UV–vis DRS (Diffuse Reflectance Spectroscopy). And the excellent photocatalytic performance of this Cu, N-CDs system was ascribed to the increased conversion of ·O〈sub〉2〈/sub〉〈sup〉−〈/sup〉 under visible light irradiations and effective separation of electron-hole pairs, results in inhibited photocorrosion of the system. Also, this nanocomposite could successfully degrade the neutral red dye (mention the concentration) about 95.5% under LED irradiations within 60 min.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719306193-ga1.jpg" width="222" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 578〈/p〉 〈p〉Author(s): Juan David Beltrán, Camilo Eduardo Sandoval-Cuellar, Katherine Bauer, María Ximena Quintanilla-Carvajal〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Liposomes are spherical vesicles which can be used as encapsulation systems for transporting and releasing many biocomposites which can be affected by conditions in the gastrointestinal tract; such affectation means that the dominant degradation mechanisms and the factors influencing such degradation must be identified by means of digestion studies. This study was thus aimed to evaluate the physical stability and intestinal digestibility of nanoliposomes (NLs) produced by microfluidization (MF) and ultrasound (US) for high oleic palm oil (HOPO) encapsulation. A standardized 〈em〉in vitro〈/em〉, three-stage (〈em〉i.e.〈/em〉 oral, gastric and intestinal) static model of the gastrointestinal tract was used which had been published by the INFOGEST research network. No statistically significant changes were observed concerning any of the properties regarding stability during the oral phase; however, both types of NL studied here became destabilized during the gastric phase by environmental conditions, such as acid pH and high ion concentration. This was reflected by increased average particle size, the polydispersity index and the Z potential. Decreased particle size was observed during intestinal digestion regarding both technologies compared to gastric phase. MF-produced NLs were larger than US-produced ones during this phase. Intestinal enzymes degraded the system’s triglycerides, leading to 116.04 ± 2.62%w MF and 80.39 ± 2.26%w US free fatty acid release.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719305862-ga1.jpg" width="389" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 578〈/p〉 〈p〉Author(s): Chengwei Wang, Lili Ma, Qingkun Wen, Baoxiang Wang, Rongjiang Han, Chuncheng Hao, Kezheng Chen〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, an electrorheological (ER) fluid containing titanium oxide@ H〈sub〉2〈/sub〉Ti〈sub〉2〈/sub〉O〈sub〉5〈/sub〉 nanotube core/shell nanocomposite was prepared via the combination of hydrothermal and solvo-thermal method. The morphological evolution was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. Furthermore, the structural characteristics of the as-obtained core/shell nanoparticles were confirmed by x-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) and nitrogen adsorption measurements respectively. Titanium oxide@H〈sub〉2〈/sub〉Ti〈sub〉2〈/sub〉O〈sub〉5〈/sub〉 nanotube core/shell nanocomposite is showed to possess tube-like and core-shell structure and enhanced ER properties under external electric fields.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571930617X-ga1.jpg" width="235" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 578〈/p〉 〈p〉Author(s): Jincheng Mao, Jizhen Tian, Wenlong Zhang, Xiaojiang Yang, Heng Zhang, Chong Lin, Yang Zhang, Zhaoyang Zhang, Jinzhou Zhao〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Gemini cationic surfactants, which have two cationic surfactant molecules connected by a spacer, have received increased attention in recent years as very good thickeners for clean fracturing fluids. We synthesized four Gemini cationic surfactants with three, four, five, and six methylene groups in the spacers. Salts can promote micelle aggregation of viscoelastic surfactants (VESs) and affect their performance and we used potassium chloride (KCl) to study the performance differences of the surfactants with different spacer lengths. The results showed that the surfactant with three methylene groups in its spacer had the lowest critical micelle concentration, and when combined with KCl in solution, it had the best salt tolerance and apparent viscosity in KCl concentrations ranging from 0.2 wt% to 2.6 wt%. In addition, the solution also exhibited an excellent viscoelasticity and a tighter network microstructure, which was confirmed by SEM observation and oscillatory measurement. We conducted rheological measurements for the four Gemini cationic surfactant fracturing fluid formulations with a shear rate of 170 s〈sup〉−1〈/sup〉 at up to 100 °C. The solution with KCl and the surfactant with the shortest spacer had distinctly superior rheological properties, and its viscosity could be maintained above 58 mPa.s after 120 min. Finally, we did proppant suspension tests, gel breaking property tests, and core matrix permeability damage rate tests on the four optimized fracturing fluid systems. The solution prepared by KCl and the surfactant with the shortest spacer was found to have the most favorable properties for fracturing fluids. These results demonstrate that decreasing the spacer length of a Gemini cationic surfactant leads to better performance in fracturing fluids.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉The effect of counter-ion salt (KCl) concentrations on 21-(3,4,5,6)-21 surfactants that the surfactant solutions were transparent at low salt concentrations, but with increasing counter-ion concentrations above a peak viscosity, the phase separation occurred in all surfactant solutions. Meanwhile, this also shows that increasing the number of carbon atoms on the spacer of the surfactants lead to a greater sensitivity to the phase separation phenomenon.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719306016-ga1.jpg" width="227" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: Available online 20 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Zechen Liu, Yangchao Xia, Qingteng Lai, Maoyan An, Yinfei Liao, Yongtian Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this investigation, a mixed collector (MC) of dodecane and n-valeric acid was used to improve low rank coal flotation. Fourier transformation infrared spectroscopy (FTIR) measurements and contact angle measurements were conducted to explain flotation responses. Furthermore, using a molecular dynamics (MD) simulation, the changes of water/collector (dodecane or MC)/coal systems were studied before and after adsorption to indicate the absorption behavior and mechanism. The results showed that a better flotation performance of low-rank coal was obtained using the MC compared to a conventional collector of dodecane. The hydroxyl (-OH) or carbonyl (C = O) or carboxyl (COOH) migration of the coal with the MC was stronger than that with dodecane as a solo collector, and the MC can enhance the hydrophobicity and lipophilicity of the coal surface. MD simulation results revealed the adsorption behavior of the MC on low-rank coal surfaces. Dodecane was mainly adsorbed on the hydrophobic surface of coal, and n-valeric acid was more inclined to act on the oxygen-containing functional group of coal, i.e., a hydrophilic surface. The mobility of = dodecane molecules on the coal surface was reduced owing to the presence of n-valeric acid, which increased the lipophilicity and hydrophobicity of the low-rank coal surface, thus attracting dodecane molecules of the MC and restricting their movement, and accelerating the departure of water molecules from the low-rank coal surfaces. There was also a higher interaction energy between the MC and low-rank coal. The simulation results are in good agreement with the measured results; this effectively explains the flotation results.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308283-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Xing-An Luo, Pei Zhao, Hai Zhang, Shu-Yi Feng, Ke-Xian Chen, Zhong-Xiu Chen〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Dietary macromolecules are often used for food formulation. Most of the published literature usually focuses on a certain polysaccharide reducing lipid digestion, but the non-specific physical effects such as the excluded volume effect of the surrounding macromolecules, which will possibly enhance the hydrolysis of lipids, is rarely discussed. As the influence of polysaccharides on the gastrointestinal fate of α-tocopherol acetate (VE-A) encapsulated in emulsion have not been conducted so far, in this research, we study the effect of crowded medium created by polysaccharides (Ficoll400) on the hydrolysis of VE-A and its bioaccessibility. The results show that the presence of Ficoll400 increased the bioaccessibility and conversion of VE-A 1.6 times that of a dilute buffer. An enzyme-catalyzed kinetic reaction rate of VE-A hydrolysis is increased up to 3.5 times. Both the improved thermodynamic conversion yields and kinetic rates of the hydrolysis of the VE-A emulsion was further observed in a synthetic macromolecule PEG2000 medium. This research improves our understanding of the crowding effect of macromolecules on VE-A/lipid emulsion digestion.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308258-ga1.jpg" width="323" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 20 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Ping Ding, Serafim Bakalis, Zhibing Zhang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Foaming in high viscous and non-Newtonian aqueous phase is generally difficult to be realised. In this work, a surfactant (Sodium Linear Alkylbenzene Sulphonate with alkyl chain lengths varying from C10 to C16) named LAS paste mixed with a co-polymer solution of acrylic acid and maleic acid denoted by Polymer solution was used to generate foam under conditions of sparging without or with agitation, which aims to be used as a coating material of detergent powders. The foam structure/morphology, bubble size, gas holdup and liquid drainage in such surfactant-copolymer system were investigated. It was found that two different types of foam were generated: 1) dispersed spherical air bubbles in highly viscous mixtures of LAS paste and Polymer solution with median size d50 in a range of 20 – 50 μm and gas holdup of 0.20 - 0.44 depending on LAS concentration, 2) bubbles with polyhedral structure in a mixture of LAS paste and Polymer solution diluted with water and size d50 = 7.0 ± 0.4 mm and gas holdup of 0.93 ± 0.05. The generated foam structures depended on the energy input, air superficial velocity, surfactant concentration and the liquid viscosity. Besides, they even depended on liquid mixing procedures before the foam was generated, resulting from different transfer rates from LAS paste phase to Polymer solution. The comparison of foam behaviours in such complex system and in single-phase liquid was made. For dispersed spherical bubbles, the median size has been correlated to energy input whilst for bubbles with polyhedral structure the characteristic size has been predicted by considering the balance between their buoyancy and viscous forces generated in the system. Based on the results, the mechanism of foam stabilisation is proposed.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308052-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Natalya Sankova, Viktoriya Semeykina, Ekaterina Parkhomchuk〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, we have studied the growing mechanism of polystyrene microspheres with a small amount of cross-linking agent (0.2–2 wt%) during dispersion polymerization (DP) in 1-butanol in presence of PVP-40 steric stabilizer. Scanning electron microscopy and dynamic light scattering showed that particles take anomalous form at first several hours due to the growth predominantly by homo- and hetero-coagulation mechanism. The duration of the coagulation process is estimated to be of about a minute. Understanding of the mechanism of particle formation in the above systems will help to overcome the problem of irreproducibility, control the preparation of anisotropic particles during DP and extend the application of these particles.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307332-ga1.jpg" width="496" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Xiaobo Nie, Wei Jiang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A facile method is introduced to tune the aggregate morphologies of ABC triblock copolymer in selective media by combining the self-assembly and hydrogen bonding. Poly(styrene)-〈em〉block〈/em〉-poly(1,4-butadiene)-〈em〉block〈/em〉-poly(2-vinyl pyridine), abbreviated for PS-〈em〉b〈/em〉-PBd-〈em〉b〈/em〉-P2VP and used as an ABC triblock copolymer, self-assembles in toluene and methanol mixture to form discoid micelles with PBd as the disk containing part of PS domains in the core, other PS as bumps and P2VP as corona, respectively. When oleic acid (OA) is added in the assembly system, supramolecular polymer PS-〈em〉b〈/em〉-PBd-〈em〉b〈/em〉-P2VP(OA) is prepared by the hydrogen bonding between OA and P2VP of triblock copolymer. As a result, biscuit-like and mushroom-like micelles are formed with assistance of hydrogen bonding. Interestingly, the biscuit-like and mushroom-like micelles can transform reciprocally by fission and fusion mechanism through varying the volume ratio of toluene and methanol. Thus, it provides a simple and convenient approach to control the aggregate morphologies of block copolymers by tuning the hydrogen bonding and selective solvent content. The multicompartment micelles from ABC triblock copolymer may present potential applications in drug delivery, targeting, catalysis and others.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308271-ga1.jpg" width="247" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 20 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Badr M. Thamer, Ali Aldalbahi, Meera Moydeen A, Abdullah M. Al-Enizi, Hany El-Hamshary, Mandeep Singh, Vipul Bansal, Mohamed H. El-Newehy〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Activated electrospun carbon nanofibers (A-ECNFs) with micro/mesoporous structures and high surface areas (1615 m〈sup〉2〈/sup〉 g〈sup〉-1〈/sup〉) were prepared using an electrospinning technique followed by carbonization and alkali activation. The adsorption of Congo red (CR) and methylene blue (MB) dyes by A-ECNFs from aqueous solutions was investigated and compared with those of pristine ECNFs. The textural characteristics and morphology of the prepared pristine and activated ECNFs were characterized using various techniques. The adsorption performance was found to be associated to the surface area, porosity, and surface charges of the prepared adsorbents; the nature and molecular size of the dyes; and the pH and temperature of the solution. Six nonlinear isotherm models were applied to analyze the adsorption equilibrium data, and the results showed that the adsorption behavior could be appropriately described using the Redlich–Peterson isotherm model. The kinetic results for the adsorption of CR and MB onto A-ECNFs were fitted reasonably well to the Elovich model and were fitted by a pseudo-second order (PSO) model onto the pristine ECNFs. According to the thermodynamic results, the adsorption of CR and MB onto the A-ECNFs was endothermic and spontaneous. In addition, the reusability of the A-ECNFs was evaluated over five adsorption-desorption cycles.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308234-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Hitomi Kobara, Kaoru Nakatsuka, Akihiro Wakisaka〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Size selected synthesis of gold nanoparticle (AuNP) was carried out by use of an ultra-fine liquid droplet as a reaction field. The ultra-fine liquid droplets were generated by electrospraying in a liquid medium. The electrospraying in the liquid medium had a great advantage over the conventional electrospraying in the air. The size of electrosprayed liquid droplets can be varied with the supplied electric voltage beyond the range of the electrospraying in the air. When the AuNPs synthesis through the chemical reduction of Au〈sup〉3+〈/sup〉 was carried out by use of this electrospraying in the liquid medium for the mixing of Au〈sup〉3+〈/sup〉 solution and the reducing agent solution, the size of AuNPs was controlled by the supplied electric voltage. Two types of reaction field equipped with a single and double electrospray nozzles were designed to be demonstrated.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉The size distribution of gold nanoparticles was controlled in the ultra-small reaction field generated by the electrospray in a liquid medium.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308246-ga1.jpg" width="440" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Kenji Aramaki, Misaki Fujii, Yuichi Sakanishi〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉One of the major drawbacks of ionic-surfactant-based wormlike micelles (WLMs) is their poor low-temperature stability, which severely limits their application. Generally, an ionic surfactant with a linear C12–C16 alkyl chain has a Krafft point around or above room temperature. Therefore, there is a demand for ionic-surfactant-based WLMs with greater lowtemperature stability. Silicone surfactants have flexible hydrophobic chain structures. Hence, they are expected to be suitable candidates for WLMs that can be stable at low temperatures. Sodium trimethylsilyl tetra(dimethylsiloxane) decyl sulfate (Si〈sub〉5〈/sub〉C〈sub〉10〈/sub〉SO〈sub〉4〈/sub〉Na) and benzyltrimethylammonium chloride (BTAC) were used as surfactant and electrolyte, respectively, to obtain the WLM system with desired properties. No precipitation of surfactant crystals was observed in the WLM system obtained in this study when temperature was decreased to as low as 0 °C, indicating excellent low-temperature stability. Steady rheological measurements on the viscous solutions show shear thinning corresponding nearly to a power law relation (viscosity ∝ [shear rate]〈sup〉−1〈/sup〉). Zero shear viscosity (〈em〉η〈/em〉〈sub〉0〈/sub〉) increased with increase in 〈em〉R〈/em〉, reaching a maximum at around 〈em〉R〈/em〉 = 0.3 and decreasing thereafter. Oscillatory shear measurements for the viscoelastic samples, formed around the maximum-viscosity composition, show that the storage modulus (〈em〉G′〈/em〉) and the loss modulus (〈em〉G′′〈/em〉), with respect to the oscillation frequency (〈em〉ω〈/em〉), cross each other and fit the Maxwell model very well in the low-〈em〉ω〈/em〉 region. The normalized Cole-Cole plot of 〈em〉G′′〈/em〉 / 〈em〉G′′〈/em〉〈sub〉max〈/sub〉 against 〈em〉G′〈/em〉 / 〈em〉G′′〈/em〉〈sub〉max〈/sub〉 was obtained as a semicircle centered at 〈em〉G′〈/em〉 / 〈em〉G′′〈/em〉〈sub〉max〈/sub〉 = 1, as is typical for WLM systems.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308295-ga1.jpg" width="356" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 20 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Jian Xiao, Honglin Luo, Haiyong Ao, Yuan Huang, Fanglian Yao, Quanchao Zhang, Yizao Wan〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Although recombinant human bone morphogenetic protein-2 (rhBMP-2) has been widely applied for bone regeneration, finding an ideal delivery system with optimal dose and minimal side effects is still a challenge. In this context, a novel mesoporous bioactive glass nanotubular (MBG-NT) scaffold loaded with rhBMP-2 was developed using a template-assisted sol-gel method. The obtained MBG-NT scaffold showed a notable 3D network structure and the nanotubes had an outer diameter of approximately 45 nm and a wall thickness of 15 nm. X-ray photoelectron spectroscopy (XPS) certified that the rhBMP-2 was successfully loaded into the MBG-NT scaffold with a quantity of 184.3 〈strong〉±〈/strong〉 5 ng mg〈sup〉-1〈/sup〉, and the MBG-NT scaffold exhibited a sustained release of rhBMP-2 for 28 days due to the presence of mesoporous structures. Moreover, the rhBMP-2-loaded MBG-NT scaffold exhibited enhanced proliferation, alkaline phosphatase (ALP) activity and osteogenic-related gene expression of human bone marrow stromal cells (hBMSCs) when compared to bare MBG-NT scaffold. We believe that the rhBMP-2-loaded MBG-NT scaffold can be a promising scaffold for regeneration of large bone defects.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571930826X-ga1.jpg" width="285" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Razieh Zahedi, Zahra Asadi, Fahimeh Dehghani Firuzabadi〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel heterogeneous catalyst was developed via the immobilization of a copper complex by covalent anchoring of the ligand on the surface of magnetic nano particles. The catalyst was characterized by various techniques including Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron micrograph (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), a vibrating sample magnetometer (VSM) and inductively coupled plasma (ICP) spectroscopy. The prepared catalyst demonstrated high catalytic activity, stability, reproducible dispersibility, and recycability in the O-arylation reactions. Moreover, the catalyst could be easily recovered under the outside magnetic field and reused without noticeable decreasing in its catalytic performance upon five consecutive runs.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307162-ga1.jpg" width="271" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Akram Abbasi, Arijit Bose〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The high electrical conductivity of multilayer graphene (MLG) and their sheet like morphology results in a low percolation threshold, and makes it an attractive filler for inducing electrical conductivity in an insulating polymer at small filler loadings. However, strong van der Waals forces between the flat faces of multilayer graphene cause agglomeration, making it difficult to disperse them in a polymer. The loading required for forming a percolating network of these MLGs then increases dramatically, and the advantage of their sheet-like morphology is lost. To enhance the dispersion of MLGs, carbon black nanoparticles (CB) were added as secondary fillers to a polystyrene (PS) matrix containing 2.5 vol% MLG. The electrical conductivity of the composite increased from 10〈sup〉−9〈/sup〉 S/m with no CB to 10〈sup〉-4〈/sup〉 S/m with 1.5 vol% CB, asymptoting to 10〈sup〉3〈/sup〉 S/m at ∼12 vol% CB. Using Raman spectroscopy and wide-angle X-ray diffraction, we confirmed that the CB particles act as dispersion aids and prevent MLG restacking, reducing agglomeration and enhancing dispersion of the MLG sheets in PS. This leads to an increase of several orders of magnitude in electrical conductivity.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307150-ga1.jpg" width="269" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Jiaoyuan Lian, Suxia Zheng, Cong Liu, Zhongbin Xu, Xiaodong Ruan〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We propose a co-flowing step emulsification strategy for the on-line control of micro-droplet generation. The effects of four parameters including wall contact angle, plateau length, channel distance and diameter are investigated numerically and experimentally in this study. The results indicate that the wall contact angle, whose applicable range can be expanded to 90°–180° by co-flow, is critical to droplet formation. The effect of the plateau length on droplet generation is reduced by the co-flow, and the droplet diameter is almost independent of the plateau length, which ranges from 0.7 to 1.5 mm. In addition, the droplet diameter increases significantly with increasing channel distance and diameter. Combining these results with those of our previous study, we derived an explicit equation for droplet diameter prediction. The predicted droplet diameter based on this equation has good agreement with the simulation and experimental results. Furthermore, we proposed a coefficient 〈em〉α〈/em〉 as a function of physical and dimensional parameters to predict the regimes and modes in the co-flowing step emulsification process. The conclusion of this study not only provides an important reference for the design and improvement of step emulsification chips, but also offers a new idea and a scientific basis for tuneable monodisperse micro-droplet production.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307216-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Biao Zhang, Xiaojuan Li, Yang Zhao, Hua Song, Huan Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Oxygen doped mesoporous graphitic carbon nitride(O-mpg-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉) was innovatively prepared through facile two-step synthesis and characterized through different characterization tools, such as XRD、SEM、XPS etc. These characterizations confirm that the as-prepared sample has separated plate-like structure with lots of gaps and oxygen atoms have been successfully doped into them. Evaluated by photodegradation of Rhodamine B and Methyl Orange, the O-mpg-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 photocatalyst exhibits higher photocatalytic degradation efficiency, which is attributed to the added active spots, shorter electronic transmission distance and wider range of light absorption. In addition, the photocatalytic activity of the as-prepared catalysts didn’t decrease significantly after five photodegradation cycles, showing a high photocatalytic stability.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Oxygen doped mesoporous g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 was firstly prepared by a facile calcination-solvothermal method and exhibits excellent photocatalytic degradation performance, which is ascribed to the change of morphology and intrinsic electronic structure.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307241-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Wenjie Liu, Kun Yuan, Peipei Liu, Ming Chen〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this article, magnetically responsive catalysts were successfully synthesized by host-guest chemistry and self-assembly strategy. Firstly, β-cyclodextrin (β-CD) was bound directly to the surface of core/shell magnetic Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@C (MFC) using chemical bonding methods. Then, in view of the host-guest recognition, p-aminothiophenol (pATP) was captured by β-CD to form inclusion complex on the surface of MFC. Lastly, pre-synthesized gold, silver, platinum nanoparticles (AuNPs, AgNPs, PtNPs) could be adsorbed on the surface of MFC@β-CD-pATP through self-assembly strategy to fabricate ternary composites MFC@β-CD-pATP@metal nanoparticles. Catalytic reduction reaction of methylene blue using NaBH〈sub〉4〈/sub〉 as reducing agent evaluates the catalytic performance of three as-prepared magnetic nanocomposites. MFC@β-CD-pATP@AuNPs catalyst showed the fast catalytic reaction rate constant. Significantly, we have explored the separation of magnetic supports and novel metal nanoparticles under mild conditions. This strategy will become a green and environmental way for highly efficient separation of precious metals catalysts, and recycle and reuse of catalyst carriers.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307174-ga1.jpg" width="362" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Piero De Leonardis, Francesco Cellesi, Nicola Tirelli〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We explored a versatile enzyme nanoencapsulation process based on the synthesis of silica gel nanoparticles, decorated with a dense hydrophilic poly(glycerol monomethacrylate) (PGMMA) shell for biological and therapeutic applications. These hybrid enzyme-SiO〈sub〉2〈/sub〉-polymer nanoparticles were obtained through an aqueous sol-gel process, followed by the adsorption of cationic macroinitiators by electrostatic complexation. Surface-initiated Atom Transfer Radical Polymerisation (ATRP) was applied to obtain a dense hydrophilic (protein repellent) PGMMA layer of tunable size, under conditions which are compatible with the nanoencapsulation of horseradish peroxidase. The sol-gel synthetic procedure, the composition and molecular weight of the macroinitiators, the polymer adsorption and purification methods, and the final ATRP conditions, were optimised to control the properties of these nanoparticles, in terms of particle size, Z-potential, PGMMA decoration, while preserving enzymatic activity.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307228-ga1.jpg" width="489" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈p〉Enzyme-SiO〈sub〉2〈/sub〉-polymer nanoparticle obtained by enzyme (HRP) nanoencapsulation in silica gel nanoparticles, adsorption of a cationic macroinitiator, and final polymer shell generation (PGMMA) by ATRP.〈/p〉 〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): F. Salerni, D. Orsi, E. Santini, L. Liggieri, F. Ravera, L. Cristofolini〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉We employ Diffusing Wave Spectroscopy (DWS) to characterize microscopic structure, internal dynamics and rheological properties of a paradigmatic emulsion formed by water and dodecane stabilized by the anionic surfactant Sodium Dodecyl Sulfate (SDS).〈/p〉 〈p〉We focus on ageing and stability in the regime of low surfactant concentration, well below the Critical Micellar Concentration (CMC). In the long-time ageing regimes differentiate in stable and unstable, depending on surfactant concentration. For the stable case, ageing affects the dynamics following a power law with an exponent independent on surfactant concentration, presumably related to the late stages of the water drainage process. On the contrary, at constant ageing, the dependence of the dynamics from surfactant concentration shows a slowdown, corresponding to a maximum in the bulk shear mechanical modulus, around 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si25.svg"〉〈mo〉[〈/mo〉〈mi〉S〈/mi〉〈mi〉D〈/mi〉〈mi〉S〈/mi〉〈mo〉]〈/mo〉〈mo〉=〈/mo〉〈mn〉2〈/mn〉〈mi〉m〈/mi〉〈mi〉M〈/mi〉〈/math〉 which is reminiscent of a similar maximum found by drop tensiometry in the dilational modulus of the single interface.〈/p〉 〈p〉This suggests a consistent picture of the mechanisms (de)stabilizing the emulsion, explained in terms of elementary process at the interface. These results show furthermore that DWS can be a reliable diagnostic for the study of the aging and of the mechanical properties of concentrate emulsions. This might be relevant to control stability of emulsions when a low concentration of surfactant is desired, e.g. for economical or environment reasons.〈/p〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719301876-ga1.jpg" width="334" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Huijian Ye, Xuanhe Zhang, Chunfeng Xu, Lixin Xu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The polymer film capacitor has been widely applied in electronics and stationary power system due to the large power density and graceful dielectric reliability. The current requirements for flexible film capacitor are mainly on the development of polymer nanocomposite with high energy density and charge-discharge efficiency during applied electric field. Here we employed the fluoro hyperbranched polyethylene-graft-poly(trifluoroethyl methacrylate) (HBPE-〈em〉g〈/em〉-PTFEMA) copolymer to exfoliate the boron nitride nanosheets (BNNSs) in low-boiling-point solvent, and then, the flexible poly(vinylidene fluoride-trifluoroethylene) (P(VDF-CTFE)) nanocomposite film incorporated with BNNSs was prepared by the simple solution casting. The stable BNNSs dispersion was obtained with assistance of fluoro hyperbranched copolymer as the stabilizer, which was adsorbed on the nanosheets via the noncovalent CH-π interaction against aggregation. The presence of fluoro segments improves the compatibility of BNNSs/P(VDF-CTFE) nanocomposite, which contributes to the large interfacial polarization. The energy density in 0.4 wt% nanocomposite achieves 6.8 J/cm〈sup〉3〈/sup〉 with charge-discharge efficiency of 66% at 300 MV/m, which is ascribed to the large content of electroactive phase and the enhanced interfacial polarization. The fluoro hyperbranched copolymer functionalized BNNSs/P(VDF-CTFE) nanocomposite film exhibits high electric storage capability as well as lightweight feature and flexibility, which is benefit to potential applications for portable and implantable electrical devices where both the weight and size are primary concerns.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571930723X-ga1.jpg" width="287" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Mohammad M. Hassan〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, multifunctional wool fabrics were produced by treating them with silver (Ag) nanoparticles in a single-stage treatment using trisodium citrate (TSC) as a reducing and capping agent. The effects of treatment parameters, such as Ag〈sup〉+〈/sup〉 concentration, pH, temperature and time on the colour strength, antibacterial and antistatic properties, and UV radiation absorption by the treated fabric were carried out. It was found that the wool fabric treated with Ag nanoparticles formed by using Ag〈sup〉+〈/sup〉 concentration of less than 1.11% on the weight of wool fibres produced very pale shade. The colour strength and UV radiation absorption capacity of the treated wool fibres increased with an increase in the concentration of Ag〈sup〉+〈/sup〉, and Ag〈sup〉+〈/sup〉 to citrate anion ratio, and also with a decrease in the treatment pH. The treatment temperature had a great effect on the colour strength of the treated fabrics and the size of Ag nanoparticles. The colour strength increased from 1.59 for the fabric treated at 55 °C to 7.74 for the fabric treated at 95 °C. The surface resistance of the treated wool fibres decreased with an increase in the concentration of Ag〈sup〉+〈/sup〉, while the colour fastness to washing decreased for the fabric treated at a higher pH. The treated fibres showed excellent antibacterial activity, UV radiation absorption capacity, and also very good antistatic properties along with an excellent colourfastness to washing. Moreover, the developed treatment is highly durable to washing as after 20 washes the treated fibres lost their colour and antibacterial activity only marginally.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308076-ga1.jpg" width="415" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 17 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Yixing Wang, Taijun He, Mengyun Liu, Jianqi Ji, Yu Dai, Yang Liu, Longbo Luo, Xiangyang Liu, Jiaqiang Qin〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Fast and efficient oil-water separation materials under harsh conditions become urgent requirement for eliminating destruction of environment from offshore oil spill, oily wastewater produced in industry and life. Here, we designed and prepared polyimide (PI) aerogel with strong hydrogen bond by introducing benzimidazole structure. The hydrogen bond increases the intermolecular interactions to overcome the expansion force and capillary force during ice crystal growth and sublimation. The obtained PI aerogel has a mutually interleaved sheet three-dimensional network structure of thin pore walls (about 85 nm), interconnected pores and tortuous channels with a low shrinkage (about 7.8%). Moreover, due to the high hydrophobicity and morphological characteristics, the PI aerogel can be used for oil-water separation continuously under different harsh conditions, such as high viscosity oil (above 570 mPa·s), oil in cold/hot water (0 °C/120 °C), corrosive solution and emulsion. The separation efficiency and maximum oil flux can reach 99. 9% and 14320 L·m〈sup〉-2〈/sup〉 h〈sup〉-1〈/sup〉, respectively. Because of their fast and efficient oil-water separation performance in harsh environments, this PI aerogel shows great potential in the field of petroleum, municipal and industrial wastewater treatment.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307976-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 13 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Junmei Tian, Zhijia Zhu, Baojiang Liu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Photocatalysts with heterojunctions had attracted much attention in the field of photocatalysis due to their strong charge separation and transfer capabilities. In this work, a novel Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉/Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉/MWCNTs Z-scheme photocatalyst was firstly prepared by one-step hydrothermal method. A series of characterization results showed that the ternary flower-like Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉/Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉/MWCNTs photocatalyst was successfully synthesized. The photocatalytic property of Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉/Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉/MWCNTs composite was evaluated by photo-degradation of reactive blue 19 (RB-19) dye under visible light irradiation. The results manifested that Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉/Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉/MWCNTs composite presented the better photocatalytic property than pure Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉 and Bi〈sub〉2〈/sub〉MoO〈sub〉6〈/sub〉/Bi〈sub〉2〈/sub〉WO〈sub〉6〈/sub〉. Additionally, in the photocatalytic process free radical and hole scavenging experiments indicated that h〈sup〉+〈/sup〉 and ·O〈sub〉2〈/sub〉- played an indispensable role. Finally, possible mechanisms for the photocatalytic enhancement of the composite were put forward.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307861-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Chao Zhang, Siyao Liu, Shuangxi Li, Yue Tao, Panpan Wang, Xinyue Ma, Lanzhou Chen〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The magnetic chitosan microspheres immobilized 〈em〉Aspergillus sydowii〈/em〉 (MCMAs) was prepared and characterized by SEM, BET, XRD and VSM analyses, and used to adsorb Cu(II) from aqueous solution under different influence factors such as contact time, initial Cu(II) concentration and biosorbent dose. Characterization results showed that MCMAs had large specific surface area and were rapidly separated from aqueous solution by using an adscititious magnetic field. Batch adsorption experiments showed that Cu(II) adsorption capacity of MCMAs was up to 119.21 mg g〈sup〉−l under the optimal condition. The CO, OH and NH〈/sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉 groups played an important role in Cu(II) chelation observed from FTIR spectra. Cu(II) adsorption onto MCMAs was well described by pseudo-second-order kinetics and Langmuir isotherm, and the adsorption process involved surface and intra-particle diffusion. In addition, MCMAs showed good recyclable efficiency after four adsorption-desorption cycles.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308015-ga1.jpg" width="334" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Suvendu Manna, Snigdha Prakash, Papita Das〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This article presents the process of synthesizing a value added product from a carbonaceous industrial waste. For this a carbonaceous industrial waste was coated with graphene oxide (GO) and then thermally activated at 800 °C. The GO and the GO-coated biochar were characterized with atomic force microscope, raman spectroscope, fourier transform infrared spectroscopy, field-emission scanning electron microscope, x-ray Diffraction and transmission electron microscope. This GO-coated biochar was then utilized to investigate removal capacity of phenol present in wastewater. The data indicated that the GO-coated biochar showed better phenol removal efficacy then that of the GO itself. The isotherm analysis indicated that the data could be described best with Langmuir isotherm indicating that the phenol separation was a monolayer surface adsorption. The kinetic analysis indicated that the phenol separation process was followed by pseudo second order kinetics. Also, it was evident from the intra-particle diffusion kinetic analysis that diffusion plays a significant role in phenol separation. From thermodynamic analysis it was evident that the phenol separation process was endothermic as well as spontaneous in nature. The GO-coated biochar showed better separation efficacy in the presence of salt.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308064-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Yong-li Yan, Qi Xi, Christian-chibuike Una, Bing-cheng He, Chun-sheng Wu, Long-long Dou〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉The serious fingering and nonuniform injectivity profile of acid liquid result from the features of heterogeneity in most carbonate reservoir, leading to a poor effect on the acidizing process. In the present contribution, for the first time, we report a novel diversion acidizing strategy that uses acid-rock reaction between the acidizing fluid itself and carbonate core to produce CO〈sub〉2〈/sub〉 at supercritical state. Under the action of a mixture of foaming agent and stabilizer contained in this working fluid, a CO〈sub〉2〈/sub〉 foamed acid fluid is in-situ formed in the acidizing layer, which would play a diverting role in carbonate matrix acidizing operations. Experiments on in-situ formation of CO〈sub〉2〈/sub〉 microfoams (emulsions) were performed utilizing a visible acid-rock reaction simulation device and a self-made high pressure and temperature foam generator. A series of divided-flow experiments were undertaken by the core displacement setup.〈/p〉 〈p〉Results based on these experiments indicate that with 0.5% SDBS as a foaming agent and 0.15% CMC as a stabilizing agent, the supercritical CO〈sub〉2〈/sub〉 microfoams (emulsions) could be created in-situ in the process of acidizing through the carbonate reservoirs. The foamed acid has the accumulating and plugging effects, with divided-flow selectivity not only in the parallel cores of oil saturation and water saturation, but also in the parallel cores of different permeability. This foamed acid fluid could provide better diversion acidizing operations for heterogeneous carbonate formation. Finally, the mechanism of this novel diversion acidizing technology was uncovered in detail. It is suggested that the whole working process is actually an interface effect in the dynamic system of gas/liquid/solid multiphase fluid. Such findings are potentially important for a better understanding on the mechanisms of in-situ formation of CO〈sub〉2〈/sub〉 foamed acid and its self-diversion. Looking out to the future, our report attempts to provide a new and efficient technology for the improvement of acid stimulation in the carbonate reservoirs.〈/p〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉A novel diversion acidizing technology using in-situ microfoams to meet the challenge of serious fingering and poor backflow of acid liquid existing in application of diverting acid technology in heterogeneous formations. This technology uses a chemical reaction between conventional acid and carbonate cores to produce CO〈sub〉2〈/sub〉 at supercritical state. Under the action of a mixture of foaming agent and stabilizer, a CO〈sub〉2〈/sub〉 foam fluid was in-situ formed, which would play a diverting role in carbonate matrix acidizing operations. It is suggested that the whole working process is actually an interface effect in the dynamic system of gas/liquid/solid multiphase fluid.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307757-ga1.jpg" width="200" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Tao Ma, Haishun Feng, Hairong Wu, Zhe Li, Jiatong Jiang, Derong Xu, Ziyu Meng, Wanli Kang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Gemini surfactant has a good application prospect in the field of enhanced oil recovery (EOR) due to the advantages of high interfacial activity, low critical micelle concentration (CMC) and good wettability alteration. In this paper, ethylenediamine, sodium 2-bromoethanesulphonate and fatty alcohol polyoxyethylene ether are used as raw materials to synthesize a new kind of anionic-nonionic gemini surfactant which hydrophilic group consists of two parts nonionic and anionic groups through a mild reaction of amination. The surface tension, interfacial tension, wettability and oil displacement of the synthesized anionic-nonionic gemini surfactants were evaluated. Parameters of surfactant the saturated adsorption amount 〈em〉Γ〈/em〉〈sub〉max〈/sub〉 and the minimum molecular occupied area 〈em〉A〈/em〉〈sub〉min〈/sub〉 were calculated. The structures of the optimal product were characterized by IR and 〈sup〉1〈/sup〉H-NMR. The results showed that the critical surface tension of the synthesized anionic-nonionic gemini surfactant was as low as 28.94 mN/m, and the critical micelle concentration was 4.9 × 10〈sup〉−5〈/sup〉 mol/L. An interfacial tension between the aqueous solution of 600 mg/L optimal surfactant and Dagang crude oil was 0.0804 mN/m. 1500 mg/L aqueous solution can reduce the surface contact angle of lipophilic low permeability core from 144.5° to 71.5°. The anionic-nonionic gemini surfactant (1000 mg/L; 0.4 PV) can improve oil displacement efficiency by 7.03%. The current study opens a new pathway for designing enhancing oil recovery applicable gemini surfactants with excellent performance, wide source of raw materials and low dosage.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307885-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Zengzi Wang, Runtao Hu, Gaihuan Ren, Gongrang Li, Shangying Liu, Zhenghe Xu, Dejun Sun〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The application of conventional alkalis (NaOH or Na〈sub〉2〈/sub〉CO〈sub〉3〈/sub〉) in alkali/surfactant/polymer (ASP) flooding is rather limited due to their intrinsic drawbacks, including precipitating during injection into formation water with a high divalent ion concentration and enhancing the dispersibility of clays (e.g., montmorillonite (MMT) or kaolinite) in water, which lead to damage to reservoir formations and bring about difficulties in treating produced fluids. Here, we propose polyetheramine D 230 as an alternative alkali to avoid these problems. D 230 is a diamine linked by poly(oxypropylene) backbones. Interfacial tension and emulsification measurements proved that D 230 can neutralize the acidic components in crude oil to generate surface-active soaps, which facilitate oil emulsification in water. Contact angle measurements indicated that an oil-contaminated quartz surface treated with D 230/SP blends was successfully altered from oil-wet to water-wet. Sand pack flooding measurements demonstrated that a D 230/SP injection was able to mobilize 19.23% of the original oil in place (OOIP) after thorough water flooding. Rheograms of alkali/polymer blends showed a reduced impact of D 230 on viscosity. Static bottle tests indicated that no precipitation occurred after D 230 was injected into formation water with a high Ca〈sup〉2+〈/sup〉 concentration. Colloidal stability measurements of clay dispersions suggested that D 230 can inhibit clay dispersibility. As an alternative alkali in ASP flooding, D 230 not only facilitates enhanced oil recovery (EOR) but also solves problems such as precipitation, high biotoxicity, reduced fluid viscosity and enhanced clay dispersibility brought about by conventional inorganic and organic alkalis. These advantages make D 230 an eco-friendly choice as an alkali for ASP flooding.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308088-ga1.jpg" width="362" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Mohsin Ali Marwat, Bing Xie, Yiwei Zhu, Pengyuan Fan, Kai Liu, Meng Shen, Malik Ashtar, Suwadee Kongparakul, Chanatip Samart, Haibo Zhang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The sandwich-structured barium titanate/poly(ether imide) (BT/PEI) nanocomposites are fabricated layer-by-layer, with outer two insulation layers (ILs) for high breakdown strength and a middle polarization layer (PL) for high dielectric constant, using solution casting technique. Consequently, the sandwich-structured BT/PEI nanocomposites with optimum BT NPs concentration in ILs and PL showed tremendously enhanced discharge energy density (〈em〉U〈/em〉〈sub〉e〈/sub〉) of 5.7 J/cm〈sup〉3〈/sup〉, which is ∼256% and ∼307% higher than the pristine PEI (with 1.6 J/cm〈sup〉3〈/sup〉) and its single-layered counterpart, i.e., 9 wt.% BT/PEI (with 1.4 J/cm〈sup〉3〈/sup〉), respectively. The similar sandwich structure also displayed a significantly higher discharge efficiency of ∼62% at very high electric field. In addition, the high-temperature hysteresis loops for optimal sandwich structure nanocomposites revealed considerably high-temperature endurance until 150 °C at 200 MV/m. The present work paves the way for using sandwich-structured linear nanocomposites in thermally stable energy storage devices.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307903-ga1.jpg" width="267" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Sabrina Matos de Carvalho, Carolina Montanheiro Noronha, Cleonice Gonçalves da Rosa, William Gustavo Sganzerla, Ismael Casagrande Bellettini, Michael Ramos Nunes, Fabiano Cleber Bertoldi, Pedro Luiz Manique Barreto〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Natural antioxidants can be incorporated into polymers to the production of active packaging, preventing the formation of off-flavors and undesirable textures in foods, increasing the foods shelf life. In this study was developed polymeric films based on poly (vinyl alcohol) (PVA) incorporated with 30, 50 and 70% of solid lipid nanoparticles entrapped α-tocopherol. PVA films were produced by the casting technique and characterized by their physicochemical, morphological, thermal and antioxidant characteristics. PVA films with nanoparticles demonstrated higher hydrophilic compared to the control film. Thermal analysis of the films showed that nanoparticles incorporation has changed the structure, decreasing the crystallinity. Moreover, films with solid lipid nanoparticles entrapped α-tocopherol demonstrated a higher antioxidant capacity, and the α-tocopherol controlled release confirmed the possibility of its use as active packaging to application in food conservation.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307812-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 19 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Yudai Chizawa, Yayoi Miyagawa, Mao Yoshida, Shuji Adachi〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Mayonnaise is a preferred dressing that is routinely used in many regions. Distribution of products containing frozen mayonnaise is highly desirable due to the development of cold chain and changing lifestyle. However, freezing and thawing of mayonnaise result into separate oil and aqueous phases. A detailed mechanism of this phenomenon is still unknown. In this study, the destabilization of frozen emulsions, using rapeseed, safflower, olive, rice bran, and soybean oils as the oil phase was examined, in which these oil phases crystallize at lower temperature than the aqueous one. The vegetable oils exhibit different crystallization behavior. Irrespective of the type of vegetable oil, it was found that smaller the difference between the storage temperature and the melting point of the oil, which was estimated from the fatty acid composition, quicker was the destabilization of the emulsion prior to the growth of the oil crystal. We consider that the change in the crystallization process of the oil phase increases the energy at the oil–water interface and destabilizes the emulsion.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571930812X-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Pablo Llombart, Mauricio Alcolea Palafox, Luis G. MacDowell, Eva G. Noya〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Controlled CTAB self-assembly is an essential prerequisite for the formation of gold nanorods with tailored shape and monodispersity. In this paper, we exploit the use of salt concentration and co-surfactant decanol for the preparation of CTAB aggregates with different morphologies. To this end we use a model of CTAB recently developed by ourselves, and perform electronic structure calculations in order to improve current point charge parametrization of decanol. Using molecular dynamics simulations with the new models, we find a sequence of structural transitions of CTAB aggregates induced by salt concentration and added cosurfactant. In pure solutions, CTAB aggregates form spherical micelles with a compact ionic shell and a diffuse double layer that can be qualitatively described with Poisson–Boltzmann theory. Addition of decanol as a cosurfactant induces a sequence of dramatic structural transitions at low surfactant concentration and allows the stabilization of compact ordered bilayers in a well defined range of intermediate decanol/CTAB ratios. At low and high decanol/CTAB ratios spherical micelles are transformed into wormlike cylindrical micelles. At intermediate decanol/CTAB ratios, fully formed bilayers are observed, with surfactants exhibiting a compact structure with strong positional and orientational order. We discuss how the controlled self-assembly of compact CTAB bilayers at low global CTAB concentration can pave the way for the selective passivation of gold facets and the controlled formation of monodisperse gold nanorods.〈/p〉〈/div〉 〈div〉 〈h6〉Graphical abstract〈/h6〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307186-ga1.jpg" width="275" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Tülin Gürkan Polat, Kayhan Ateş, Süleyman Bilgin, Osman Duman, Şükrü Özen, Sibel Tunç〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, gelatin-based conductive hydrogels doped with carbon nanotube (CNT), poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and silver (Ag) nanoparticle were prepared for use in biopotential measurements. Gelatin was modified by various concentrations of methacrylic anhydride (MA) to obtain photo-crosslinkable gelatin methacrylate (GelMA) polymer with low (21%), medium (44%) and high (78%) methacrylation degree. Chemical modification of gelatin was characterized by 〈sup〉1〈/sup〉H-NMR spectroscopy. It was observed that mechanical properties of the GelMA hydrogels were highly dependent on methacrylation degree. Ultimate compressive stress of low, medium and high methacrylated gelatin hydrogel was measured to be 9.97 ± 0.14 kPa, 17.83 ± 1.73 kPa and 38.23 ± 2.96 kPa, respectively. Surface morphology of hydrogels was visualized by scanning electron microscope (SEM). The pore size of methacrylated gelatin hydrogel significantly reduced with the addition of CNT, PEDOT:PSS and Ag nanoparticle into the hydrogel matrix. The results of thermal gravimetric analysis showed that conductive hydrogels were of higher thermal stability than nonconductive GelMA hydrogel. The suitability of the prepared hydrogels for biopotential measurements was determined by equivalent impedance measurements. Impedance values of hydrogel samples were obtained in the frequency range of 20 Hz–500 Hz. The hydrogel materials prepared in this study exhibited high impedance at low frequencies and low impedance at high frequencies. The results of this study showed that the hydrogels produced with Ag nanoparticle are more suitable electrode materials for physiological measurement systems such as electrocardiography (ECG) and electroencephalography (EEG).〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307393-ga1.jpg" width="438" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Siddhesh Kamat, Runxing Lin, Yee C. Chiew〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Reduction of interfacial tension caused by surfactants at oil/water interfaces plays a crucial role in many technological processes and industrial applications such as detergency, food processing, cosmetics and personal care, wastewater treatment, pharmaceutical and oil industries. The properties and behavior of dispersions, foams, and emulsions are determined by the interfacial properties stabilized by the surfactants. We carried out molecular dynamics simulations to study the interfacial properties, structure and dynamics of dodecanedioic dicarboxylic acids at hexane/water interface over a wide range of surface coverage (area per molecule). Unlike monocarboxylic acid whose hydrocarbon tail points to the oil phase normal to the oil/water interface, the two carboxyl groups of the dicarboxylic acid are attached to the aqueous phase while its slightly curved carbon backbone lies parallel to the interface. The dodecanedioic dicarboxylic acid adopts a slightly curved linear conformation in the interfacial region. The adsorbed acids undergo a first-order gas-to-liquid phase transition as the density of acid increases. The characteristic thickness of the acid layer remains practically constant at large area per molecule (or, low surface density) until surface coverage reaches a “critical” value above which the thickness of the acid layer increases markedly deviating from its low density value. This layering transition has a significant influence on the spreading pressure, interfacial structure, and lateral diffusion coefficient of the acids. Additionally, we modeled a system of fully deprotonated negatively charged acids balanced by positively charged sodium counterions. We found that the interfacial tension of the charged acid interface is consistently lower than uncharged acid at moderate to higher surface density; however, at low densities, we observe little difference in interfacial tension between these two systems within the accuracy of the MD results. Additionally, we found that the rotational relaxation of the charged acids is significantly slower than that of uncharged acids owing to strong electrostatic interactions between the carboxyl groups COO〈sup〉−〈/sup〉and sodium Na〈sup〉+〈/sup〉cations which restrain the rotational motion of the acid. This molecular dynamics study has provided information and insights at the molecular level on the structure, equilibrium, and dynamic properties of dicarboxylic dodecanedioic acids at hexane/water interface.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307137-ga1.jpg" width="494" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Xinyu Zheng, Huaili Zheng, Yuhao Zhou, Yongjun Sun, Rui Zhao, Yongzhi Liu, Shixin Zhang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Wastewater containing dyes poses a severe threat to human health and to environmental safety. Hence, finding an effective way to treat this wastewater has attracted wide attentions. In this study, quaternary ammonium group-rich magnetic nanoparticles (MNPs), Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@SiO〈sub〉2〈/sub〉-MPS-g-DAC (FSMD), were facilely prepared by grafting polymerization and served as a cationic adsorbent to remove anionic dye Orange G from aqueous solutions. Being compared with Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉@SiO〈sub〉2〈/sub〉-MPS MNPs, the adsorption capacity of FSMD MNPs was notably enhanced and it could be maintained in a high level under a wide solution pH range. The dependency on pH and the sensitivity to ionic strength indicated that the main adsorption mechanism was the electrostatic interaction. The adsorption kinetics followed the pseudo-second-order model, and the adsorption isotherms were well described with the Langmuir model. According to the thermodynamic analysis, the adsorption process was spontaneous and endothermic. FSMD MNPs were proved to have advantages of fast adsorption rate, high adsorption capacity, easy separation ability under external magnetic field, and satisfactory reusability, therefore they can be applied in the removal of anionic dyes from wastewater.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307344-ga1.jpg" width="370" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Du Ren, Yujie Chen, Hua Li, Hafeez Ur Rehman, Yunli Cai, Hezhou Liu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Shape memory assisted self-healing polymeric networks have been numerously explored due to their multi-functionality and sustainability. In this study, we prepare a kind of electrical and thermal dual-responsive shape memory assisted self-healing polymeric composites fabricated with polycaprolactone/thermoplastic polyurethane (PCL/TPU) and carbon nanotubes (CNTs) via a facile method. The CNTs/PCL/TPU composites use PCL/TPU blend as shape memory polymer matrix, PCL as healing agent and CNTs as reinforcement networks. CNTs greatly enhance mechanical strength of the composites with good electrical and thermal conductivity. Interestingly, the CNTs/PCL/TPU composites can be healed via electricity and heating respectively in tens of seconds with corresponding optimal healing efficiencies about 96% and 94%. Meanwhile, the composites can exhibit remarkable electro-active shape recovery property that assist to diminish the crack openings and then the healing agent would be molten to fill in the crack. Therefore, the proposed materials can offer great potential applications in biomedical, aerospace and microelectronics.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307198-ga1.jpg" width="343" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): J. Carneiro, J.B.L.M. Campos, J.M. Miranda〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study reports the generation and characterization of polydimethylsiloxane (PDMS) microparticles. Droplets are produced in the jetting regime by hydrodynamic flow focusing technique in a PDMS square-section microchannel and afterwards thermally cured. Both the droplets and microparticles size distributions are characterized and compared. During the curing process, there is no appreciable shrinking of the droplets/microparticles. Droplets are generated with a maximum frequency of 1.3 kHz and their diameter ranges from 27 to 59 μm depending on the flow rate ratio. After the cure, the microparticles are chemically and optically characterized. The results show that the droplet generation method and the curing process are able to produce PDMS microparticles with low size, low dispersity and optimal optical properties for visualization and velocimetry experiments.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307253-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Li Duan, ChenChen Qin, Anhe Wang, Shengtao Wang, Jieling Li, Shuo Bai〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this paper, uniform and porous gelatin microgels with various functional nano-objects (platinum nanoparticles and magnetic nanoparticles) were prepared by a ‘casting’ strategy in a controllable manner. During the microgels fabrication, two kinds of nanoparticles can be simultaneously introduced into the microgels without mutual influence, endowing the microgels with the combined functionality of nano-objects. Experimental data showed that the microgels with various nano-objects are stable enough in strong base or acidic solution, and can be taken as an efficient catalysis system and conveniently separated from the reaction medium by magnetic field. The method proposed here is certified to be facile, efficient and low cost to fabricate stable multifunctional microgels.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307472-ga1.jpg" width="259" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Yaya Ma, Cuiqing Zhang, Chengyu Li, Feng Qin, Lin Wei, Changyuan Hu, Quanhong Hu, Shuwang Duo〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Bi〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 is a newly found semiconductor photocatalyst with visible-light response property; however, due to its large particle size, the photocatalytic efficiency is greatly limited. Reducing the particle size down to nanoscale is an efficient way to enhance the photocatalytic ability, but still challenging. Herein, the firework-shaped hierarchical TiO〈sub〉2〈/sub〉 microsphere was used as the framework to spatially confine the growth of Bi〈sub〉2〈/sub〉O〈sub〉4〈/sub〉. SEM characterization results reveal nanosized Bi〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 particles are successfully inserted into the TiO〈sub〉2〈/sub〉 microsphere, forming enormous Bi〈sub〉2〈/sub〉O〈sub〉4〈/sub〉/TiO〈sub〉2〈/sub〉 heterojunctions. Benefitted from the nanoscaled Bi〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 and the formation of Bi〈sub〉2〈/sub〉O〈sub〉4〈/sub〉/TiO〈sub〉2〈/sub〉 type II heterojunction, both the separation efficiency of charge carriers and the quantum yield are improved. As a result, Bi〈sub〉2〈/sub〉O〈sub〉4〈/sub〉/TiO〈sub〉2〈/sub〉 heterojunctions show much higher photocatalytic activity than that of pristine Bi〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 in the degradation of methyl orange and tetracycline under visible light. Radical capture experimental results imply that hole is the dominant reactive species for the degradation of methyl orange. The present work paves the way for designing nanosized photocatalyst via the space-confined effect.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉A space-confined strategy is developed to restrict the size of Bi〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 down to nanoscale level and as-constructed Bi〈sub〉2〈/sub〉O〈sub〉4〈/sub〉/TiO〈sub〉2〈/sub〉 heterojunctions display superior photocatalytic performance than pure Bi〈sub〉2〈/sub〉O〈sub〉4〈/sub〉.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307459-ga1.jpg" width="283" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): A.M. Hezma, A. Rajeh, Mohammed A. Mannaa〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Zinc oxide nanoparticles were prepared by a sol-gel method and characterized by XRD, SEM, TEM and EDX. A series of chitosan and polyvinyl alcohol (Cs/PVA) blend films doped with various concentrations of Zinc oxide nanoparticles (ZnO NPs) were prepared by solution casting method. These samples were characterized by various analytical techniques. XRD patterns of the prepared samples showed increasing in amorphousity of the polymer blend with increasing the content of ZnO NPs in Cs/PVA blend. The FT-IR analysis confirmed the complexation between Cs/PVA blend and ZnO NPs. From the UV–vis results, the optical energy gap was calculated. The TGA analysis displayed that the thermal stability of all the samples improved after the addition of the ZnO NPs. By the tensile universal testing machine, the mechanical properties of the prepared films were determined. The antimicrobial analysis showed that all nanocomposite films exhibited enhanced antimicrobial efficacy as compared to pure Cs/PVA film and it is linearly related to the amount of ZnO nanoparticles in the matrix. The sample containing 10 and 15 wt.% ZnO NPs exhibited the highest thermal stability, mechanical strength, and antibacterial activity. This nanocomposite with excellent thermal stability, tensile and antibacterial properties can be potentially utilized for antimicrobial packaging purposes and can be widely used in medical applications.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571930809X-ga1.jpg" width="256" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Ya Di, Kunling Lu, Yaling Tian, Yan Liu, Yunwang Zhao, Yue Zheng〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Two-phase synthesis is an advantageous alternative to the traditional synthetic method, due to its less toxicity, controllable, mild synthetic conditions and easy large-scale synthesis. However, meeting novel synthesis, the conventional trial-and-error approach could not provide a clear understanding. We herein report synthesis and mechanism investigation of CdS quantum dots in octadecene/glycerol two-phase system. The effects of different reaction parameters and conditions including reaction temperature, reaction time, reactant concentrations, and synthesis routes (one-step and two-step approach) on both nucleation and particle growth were investigated. It was found that the synthesis course was a growth dominated process depending on both CdS(monomer) and CdS(nuclei), and controlled by the interface of ODE/glycerol. The present work provided a new and clear understanding about two-phase system synthesis on semiconductor quantum dots, noble metal nanocrystals and some alloy nanomaterials.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308003-ga1.jpg" width="377" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Huey-Shan Hung, Da-Tian Bau, Chun-An Yeh, Mei-Lang Kung〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉〈strong〉Gold〈/strong〉nanoparticles (AuNPs) have well applied in imaging and carriers of drugs and/or biomolecules for diseases and cancers therapeutics, due to their tunable physicochemical properties, easy functionalized with biomolecules and biocompatibility. AuNPs conjugated with biopolymer such as collagen has been demonstrated that increased the cell proliferation, migration and cell differentiation. Avemar (Ave) is a nutraceutical from natural components and dietary supplement for healthcare of tumor related anorexia/cachexia. Moreover, Ave has revealed the excellent bio-efficacy of anti-proliferation, cell cycle disturbing and apoptosis induction in numerous types of tumor cells in 〈em〉in vivo〈/em〉 and 〈em〉in vitro〈/em〉. However, the effects of Ave on cellular uptake mechanisms still unclear. In this study, we fabricate the Ave-deposited AuNP-collagen nanocarrier (AuNP-Col-Ave) and investigate their endocytic mechanisms in transformed SCC oral cancer cells and non-transformed BAEC and HSF cell lines. By using DLS assay, Ave-deposited AuNP-Col have shown a particle size of 303 ± 35.2 nm. Both UV–vis absorption assay and FTIR spectrum analysis were also demonstrated that the Ave conjugated onto AuNP-Col. Further, both MTT assay and Calcein AM assay were revealed that AuNP-Col-Ave induced a significant cytotoxicity in cancerous SCC cells and showed nontoxicity and biocompatibility for non-transformed BAEC and HFS cells. In addition, AuNP-Col-Ave has showed an excellent uptake capacity in all these cell lines as compared to AuNP-Col group. Further uptake mechanisms analysis demonstrated that the macropinocytosis seems to be the favorite endocytic mechanism during AuNP-Col-Ave internalized into these transformed and non-transformed cell lines. Altogether, this study is first validating the endocytic mechanisms of AuNP-Col-Ave in transformed and non-transformed cell lines. Our findings will provide a novel insight for endocytic mechanisms of cellular uptake nutraceuticals during nutrition therapy and cancer prevention.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Schematic diagram illustrated that AuNP-Col-Ave-mediated cellular uptake mechanisms and cell fates in both transform and non-transformed cell lines.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307794-ga1.jpg" width="217" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Allan Gomez-Flores, Scott A. Bradford, Lei Wu, Hyunjung Kim〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Particles of various shapes (e.g., spheres or rods), sizes (e.g., nm to microns), interiors (e.g., solid or hollow), and materials are used in many industrial and environmental applications. The Derjaguin–Landau–Verwey–Overbeek (DLVO) theory has commonly been used to calculate and predict the adhesive interaction of these particles with solid surfaces. However, DLVO theory treats these particles as equivalent spheres for simplicity ignoring shape in numerous cases. The surface element integration (SEI) approach allows DLVO theory to be extended for different particle shapes, orientations, and interiors. In this study, the SEI approach was applied to calculate the interaction energy between hollow and solid cylinders with a flat surface. The effect of aspect ratio and particle orientation on interaction energies was investigated under different solution chemistry conditions. Our study is relevant for an extensive range of particle aspect ratios, ranging from nanosized particles such as carbon nanotubes or nanowires, which have high aspect ratios, to micron-sized particles such as bacteria, which have low aspect ratios. The energy barrier tended to increase when the angle that the larger axis of the particle made with the normal to the surface changed from perpendicular (0 rad) to parallel (π/2 rad). The aspect ratio did not affect the trend of the energy barrier for solid (200–1000) and hollow (25–1000) cylinders of relatively high aspect ratios, but it produces a non-monotonic trend for solid (2–100) and hollow (2–10) cylinders of low aspect ratios. The present study advances our understanding of adhesive interactions for particles having a wide range of aspect ratios and interior properties at various orientations with the surface.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307691-ga1.jpg" width="310" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Xiaoqin Huang, Yanli Niu, Zeping Peng, Weihua Hu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Core–shell structured BiOCl@polydopamine (BiOCl@PDA) hierarchical hollow microspheres were synthesized as an efficient photocatalyst towards degradation of pollutants under visible light. As-prepared BiOCl@PDA features hierarchical hollow microsphere structure formed by aggregated BiOCl nanosheets with PDA thin film coated on their surface. It exhibits excellent photocatalytic activity and recycling durability for photodegradation of pollutants under visible light illumination. Detail investigation suggests that the introduction of PDA significantly improves the specific surface areas and enhances the light absorption and interfacial separation, together to improve the photocatalytic efficiency. This work may provide a valuable strategy for the synthesis of highly efficient photocatalysts.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307356-ga1.jpg" width="222" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Sanaz Ghiasi, Ali Behboudi, Toraj Mohammadi, Samaneh Khanlari〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, negatively charged Polyethersulfone (PES)/Polyimide (PI) ultrafiltration membranes were fabricated in order to enhance membrane performance. Moreover, the surface properties such as surface charge and roughness were studied as essential properties which can enhance Polyethyleneimine (PEI) nanofiltration layer assembly. Due to the possibility and observation of phase segregation, for the first time, PES/PI blend was investigated and approved both thermodynamically and experimentally via DSC and FESEM analysis. Highly charged surface of fabricated ultrafiltration (UF) blend membranes were able to reject BSA more than 95% due to smaller pores, surface roughness, and electrostatic forces according to the AFM and zeta potential analyses. Fouling parameters depicted lower fouling with increasing the PI content. Further investigations provided evidence that the presence of PI greatly affected membrane morphology, phase separation behavior, and pore size distribution. According to zeta potential and AFM analysis, the presence of negative charge along with increased roughness of blend membrane surface drastically enhanced the formation of positively charged hyperbranched polyethyleneimine NF layer. As seen in FESEM images, using the blend membranes as substrate enhanced the NF layer assembly by increasing the interfacial affinity resulting in more efficient layer assembly of the NF layer. The NF membranes exhibited high flux (52 LMH/bar) at low pressure (2 bar) in salt removal filtration tests along with increased performance in salts rejection in order of MgSO〈sub〉4〈/sub〉 (72%) 〉MgCl〈sub〉2〈/sub〉 (62%) ≥NaCl (61.4%).〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307411-ga1.jpg" width="242" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Paola Fincheira, Olga Rubilar, Javier Espinoza, Washington Aniñir, Loreto Méndez, Amedea B. Seabra, Andrés Quiroz〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Oil-in-water (O/W) multilayer emulsions have been used to encapsulate volatile organic compounds (VOCs). Nevertheless, research associated with application in horticulture has been poorly studied. The objective of this study was to develop O/W emulsions for releasing VOCs to induce vegetable growth. Emulsions were prepared with vegetable oil, soybean lecithin and polysaccharides to formulate a stable product. The results indicated that O/W emulsions formulated with chitosan and sodium alginate were stable in a wide range of pH, temperature, and ionic strength. Furthermore, a direct relation between emulsions stability and VOC carbon was observed. The 2-nonanone (50–250 ppm) released from O/W emulsions increased the foliar length on L. 〈em〉sativa〈/em〉 and 〈em〉S. lycopersicum〈/em〉. Additionally, root lateral number was increased in 〈em〉S. lycopersicum〈/em〉 after exposition to released 2-nonanone. Surface elements as carbon, oxygen, and nitrogen were increased on leaves. It empathized that total nitrogen of both vegetables increased with exposition to 2-nonanone. Therefore, O/W emulsions can be an effective tool to microencapsulate VOCs with potential horticulture application.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307265-ga1.jpg" width="442" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Qidong Huang, Xin Li, Sili Ren, Wuhui Luo〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Xanthate is a widely used collector in the flotation of sulfide minerals and discharge of xanthate-bearing solution could cause detrimental effects on ecological balance. In this study, the cationic gemini surfactant, butane-1,4-bis(dodecyl dimethyl ammonium bromide) (gBDDA), was applied to modify montmorillonite (Mt) for removal of ethyl, isobutyl, and isoamyl xanthates from aqueous solution. Different amounts of gBDDA that were stoichiometrically equivalent to 0.5 and 1.0 times the cation exchange capacity of Mt were used to investigate the effects of gBDDA dosage on xanthates removal by the obtained products (gOMt). Characterization results of gOMt by X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetric analysis showed the successful intercalation of gBDDA into the interlayer space and the higher content of gBDDA on the external surface of gOMt-1.0. Ion exchange and hydrophobic interaction accounted for the similar adsorption capacities of gOMt-1.0 for three xanthates (ca., 0.6 mmol/g), regardless of the molecular structure of xanthates. The rapid adsorption rate and high selectivity of gOMt to xanthates were obtained as supported by the complete removal within 60 min and the stable uptake in the sulfate-coexisting system, respectively, suggesting that gOMt could be a promising adsorbent for removal of xanthates from aqueous solution.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307125-ga1.jpg" width="424" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 6 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Yi Xiao, Zeqing He, Renshan Wang, Xueqin Tao, Benxia Li〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Notwithstanding intensive research in recent decade, the conspicuous restrictions in photocatalysts still remain as low utilization of visible light, poor charge transfer/separation, and insufficient surface active sites. Designing semiconductor heterostructures as photocatalysts is a promising approach to enhance the photocatalytic efficiency for degrading organic pollutants. In this work, a novel WO〈sub〉3〈/sub〉/BiOCl p–n heterostructure photocatalyst with optimal molar ratio was successfully fabricated by growing BiOCl nanosheets on WO〈sub〉3〈/sub〉 nanofibers through the electrospinning method followed with a solvothermal process. The optical properties and photoelectrochemical tests indicated that the WO〈sub〉3〈/sub〉/BiOCl heterostructures possess high ability of photogenerated charge separation. The photocatalytic performance of the as-obtained materials was assessed by the degradations of rhodamine B (RhB) and phenol in water under visible light. Compared with pure WO〈sub〉3〈/sub〉 nanofibers and BiOCl nanosheets, the WO〈sub〉3〈/sub〉/BiOCl heterostructure catalysts showed improved photocatalytic efficiencies, and the apparent rate constant of RhB degradation is 0.259 min〈sup〉−1〈/sup〉 on the optimal WO〈sub〉3〈/sub〉/BiOCl(2) sample, which is about 2.3 times that of pure BiOCl (0.113 min〈sup〉-1〈/sup〉). The roles of different active species in the photocatalytic system were determined by active-species-eliminating experiments, revealing that the photogenerated holes play a leading function in the degradation of organic pollutants. The enhanced photocatalysis of WO〈sub〉3〈/sub〉/BiOCl(2) heterostructures results from the joint effect of high activity of BiOCl nanosheets, anti-agglomeration of WO〈sub〉3〈/sub〉 nanofibers, and well-matched straddling band-structures for charge separation. This photocatalyst presents great potential in the removal of organic pollutants from aquatic environment.〈/p〉〈/div〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571930740X-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈p〉The novel WO〈sub〉3〈/sub〉/BiOCl heterostructure photocatalyst exhibits improved photocatalysis for degrading organic pollutants under visible light.〈/p〉 〈/div〉

Description: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): O. Gmach, A. Bertsch, C. Bilke-Krause, U. Kulozik〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The aim of this study was to investigate the effect of oil type, i.e. sunflower, rapeseed, peanut and corn oil on the emulsification effect. Knowledge about the impact of the different oils on the emulsification process in a head-to-head comparison is lacking. The hypothesis was that various oils as such or with their special compositions of by-products will have an impact on the properties of the resulting emulsion. As a novel aspect, a single fraction of egg yolk (EY), i.e. the egg yolk granules, were used as emulsifier. Because of their different sources and production processes, the oils differ in composition of fatty acids, degree of saturation and contain various surface-active components like cell membrane fragments, phospholipids and vitamins which influence the emulsification process and therefore the emulsions. In addition, the pH value of the aqueous phase was varied in a broad range. The dynamic interfacial tension between oil and water as well as the adsorption behavior of granules at the interface was analyzed by drop shape analysis. Oil-in-water emulsions with high ratio of dispersed phase (80%) were produced using a colloid mill. The resulting particle size distribution was determined by laser diffraction. There were significant differences in interfacial tension and adsorption of surface-active components at the interface among the oils due to their composition, fatty acid chain length and ratio of mono-, di-, and triglycerides, resulting in different droplet sizes ascribable to the oils. A correlation could be found for the initial decrease of the analytically measured interfacial tension at the oil-water interface and the resulting emulsion droplet size. Furthermore, it could be shown that the droplet size of the emulsions decreased with increasing pH-value of the continuous phase.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307769-ga1.jpg" width="482" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Yulia V. Kuznetsova, Ilse Letofsky-Papst, Benedikt Sochor, Bernhard Schummer, Alexander A. Sergeev, Ferdinand Hofer, Andrey A. Rempel〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A simple shell-creating technique for the synthesis of CdS nanoparticles covered by ZnS is presented, which also contributes to the understanding of their low quantum yield and luminescence intensity in water, which is usually below 0.01%. The CdS nanoparticles with about 0.8 nm thick ZnS shell were synthesized in a colloidal aqueous solution and stabilized by EDTA. The CdS carrier lifetime and the quantum efficiency is greatly increased. For the latter, values up to 2.7% were achieved. A mechanism for the CdS nanoparticle luminescence in the aqueous solution is proposed, which is based on radiative recombination of charge carriers with structural defects. It was found that the synthesis of CdS in air leads to the inclusion of oxygen atoms in the structure of nanoparticles, which strongly effects the luminescence spectrum. These results show that most of the CdS luminescence centers are localized inside the nanoparticle.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308027-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 12 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Ali Esfandyari Bayat, Reza Shams〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In recent decades, utilizing of water-based muds (WBMs) in drilling oil and gas wells is ever increasing comparing to oil-based muds and synthetic-based muds due to the lower environmental issues. However, the main drawbacks with WBMs are rheological properties inefficiency and shale swelling which have caused attentions turn to improvement of WBMs’ rheological properties. In this study, the effects of various nanoparticles (NPs) namely titanium dioxide (TiO〈sub〉2〈/sub〉), silicon dioxide (SiO〈sub〉2〈/sub〉), and zinc oxide (ZnO) on improving rheological properties and shale recovery rate of a WBM sample at two temperatures (25 and 50 °C) were investigated. The concentrations of NPs in the base mud were set at 0.01, 0.05, 0.1 and 0.5 wt%. The results revealed that by adding NPs, the plastic viscosity (PV) of base mud was noticeably increased at the both temperatures. The optimum concentration of all NPs for increasing PV was found to be 0.01 wt%. Furthermore, by increasing concentration of ZnO and SiO〈sub〉2〈/sub〉 NPs up to 0.5 wt%, the base mud yield point value was considerably risen to around 13.3%, while by increasing concentration of TiO〈sub〉2〈/sub〉 NPs, the mud yield point values were reduced to 23.5 and 20.2 (lb/100 ft〈sup〉2〈/sup〉) at 25 and 50 °C, respectively. The optimum ZnO, TiO〈sub〉2〈/sub〉, and SiO〈sub〉2〈/sub〉 NPs concentrations for this purpose were found to be 0.05, 0.01, and 0.1 wt%, respectively. Moreover, ZnO and SiO〈sub〉2〈/sub〉 NPs at concentrations below 0.05 wt% had the best performances for filtration loss control. The related reason is higher stability of these NPs in the aqueous phase and consequently, better mud cake pores filling act by them which caused the mud cakes permeabilities were noticeably reduced. Besides that, SiO〈sub〉2〈/sub〉 NPs caused the highest 10 sec and 10 min gel strength values and ZnO and TiO〈sub〉2〈/sub〉 NPs in order had the lowest 10 sec and 10 min gel strength values at all applied concentrations and temperatures. Finally, by increasing concentrations of all NPs, shale recovery rates have noticeably risen comparing to the base mud. SiO〈sub〉2〈/sub〉, ZnO and TiO〈sub〉2〈/sub〉 NPs in order were successful additives for shale recycling.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307800-ga1.jpg" width="292" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 13 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Ming Yang, Qianhui Bai〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Water pollution has become a great problem and aroused worldwide concern. As a new class of materials, metal-organic frameworks (MOFs) exhibit significant potential for wastewater treatment due to their high surface area, porosity, stability and tunability. In this work, flower-like hierarchical Ni-Zn MOF microspheres were synthesized via a facile solvothermal method. The mole ratio of Ni to Zn had a great influence on the morphology and microstructure of the final products. With the increase mole ratio of Zn to Ni, the morphology of MOFs gradually changed from spheroidal structure to rod-like structure. Using the Congo red (CR) experiment to evaluate the adsorption performance, Ni-Zn MOF displayed superior adsorption capacity towards CR (460.90 mg g〈sup〉-1〈/sup〉), compared with Ni MOF (276.70 mg g〈sup〉-1〈/sup〉) and Zn MOF (132.20 mg g〈sup〉-1〈/sup〉). Besides the tuned morphology and pore structure, electron transferring from Zn species to Ni species would also favor the physicochemical adsorption of Ni-Zn MOF towards CR.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307836-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈p〉Ni-Zn MOF synthesized via solvothermal method exhibited a superior adsorption performance towards Congo red. Due to the synergistic effect of Ni and Zn species, the Ni-Zn MOF exhibited a superior adsorption performance compared with Ni MOF and Zn MOF.〈/p〉 〈/div〉

Description: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Yanyan Pei, Zhuwu Jiang, Liangjie Yuan〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Recently, MgO has been demonstrated to be a promising adsorption material for dye removal from wastewater due to its unique characteristics. However, the low surface area and recyclability have seriously limited its practical application in water treatment. Herein, MgO was introduced to mesoporous MCM-41 to improve its surface properties. A series of MCM-41/MgO nanocomposites with high surface areas (˜1000 m〈sup〉2〈/sup〉/g) and mesostructures were synthesized by a facile in situ method. Compared with pure MgO and MCM-41, the mesoporous MCM-41/MgO exhibited enhanced adsorption capacity and superior recycling stability for fast removal of an organic dye from water. The maximum adsorption capacity for crystal violet (CV) can reach 1861.38 mg/g, which is several times higher than that of MgO itself and of most other adsorbents. Even after five consecutive cycles, the removal efficiency is still up to 90%. It is expected that the mesoporous MCM-41/MgO materials will have a considerable potential in wastewater treatment.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉A facile synthetic strategy was developed to fabricate MCM-41/MgO nanocomposities with ultrahigh adsorption performance and excellent recycling stability.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719308040-ga1.jpg" width="403" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 20 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 581〈/p〉 〈p〉Author(s): Shasha Ai, Xu Guo, Lei Zhao, Dan Yang, Hanming Ding〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Prussian blue analogues (PBAs) have gained extensive attention for peroxymonosulfate (PMS) activation. However, the poor recovery ability of PBAs has limited their practical applications. In this work, PBA was firstly immobilized using zeolitic imidazolate framework-8 (ZIF-8) 〈em〉via〈/em〉 a facile 〈em〉in-situ〈/em〉 growth method. The decoration of PBA onto the surface of ZIF-8 was well confirmed by TEM, XRD, FTIR and XPS. The catalytic efficiency of the PBA-ZIF8 composite was significantly higher than that of pure PBA and ZIF-8 on the activation process of peroxymonosulfate when rhodamine B (RhB) was employed as a target contaminant. RhB degradation efficiency was effectively promoted at relatively high PBA-ZIF8 dosage and PMS concentration, as well as in near-neutral pH medium. Sulphate radicals obviously played a predominant role in attacking RhB during the whole reaction. In addition, PBA-ZIF8 also possessed good stability and reusability with negligible cobalt leaching. Therefore, the PBA-ZIF8 composite was a conveniently prepared and promising catalyst that may be employed to remediate contaminated water due to its excellent catalytic activity and recyclability.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307848-ga1.jpg" width="408" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 15 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Qingsong Hu, Sheng Yin, Yi Ding, Ting Wu, Ming Li, Bin Wang, Yong Chen, Jun Di, Jiexiang Xia, Huaming Li〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel sphere-like g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/PbBiO〈sub〉2〈/sub〉Cl 2D-3D composite photocatalyst was fabricated 〈em〉via〈/em〉 a reactive ionic liquid 1-hexadecyl-3-methylimidazolium chlorine ([C〈sub〉16〈/sub〉mim]Cl) assisted one-pot solvothermal method. [C〈sub〉16〈/sub〉mim]Cl could act as Cl source, dispersing and template agent in the meantime, which ensured the construction of PbBiO〈sub〉2〈/sub〉Cl porous microspheres and high dispersity of ultrathin g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉. Various techniques were adopted to investigate the morphology, structure, optical and electrochemical properties of the obtained catalysts. It could be observed that ultrathin g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 was dispersed evenly around PbBiO〈sub〉2〈/sub〉Cl microspheres. The colorless contaminants including bisphenol A (BPA), ciprofloxacin (CIP) and colored rhodamine B (RhB) were selected as the model pollutants to appraise the photocatalytic performance of the as-prepared samples. Compared with single PbBiO〈sub〉2〈/sub〉Cl, the composites presented obviously enhanced photocatalytic performance under the irradiation of visible light, and the optimum mass ratio of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 was around 3 wt%. The improvement of photocatalytic activity could be ascribed to the tight interfacial contact between the two components that could promote the separation and transfer of photogenerated electron-hole pairs. Superoxide radical (•O〈sub〉2〈/sub〉-), holes and hydroxyl radical (•OH) all participated in the photocatalytic reactions on account of radicals quenching experiments and electron spin resonance (ESR). This research extends the knowledge into the construction of other 2D-3D composite photocatalysts with preferable photocatalytic activities in the field of environmental remediation.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307927-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Jiajia Lu, Yanxia Kou, Xiangmei Jiang, Meijuan Wang, Yuanyuan Xue, Bowen Tian, Liang Tan〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As the sensing film on the electrode surface, some composites consisted of the conducting polymer and the different types of nanomaterials exhibit the improved electroconductivity and catalytic ability in comparison with those composed of the individual components. But their preparation generally requires a multi-step and relatively complicated process. Here a glassy carbon electrode (GCE) modified with poly(glyoxal-bis(2-hydroxyanil)) (PGBHA), amino-functionalized graphene quantum dots (afGQDs) and MnO〈sub〉2〈/sub〉 nanoclusters (MnO〈sub〉2〈/sub〉 NCs) was fabricated based on a one-pot protocol using the cyclic voltammetric scan. The scanning electron microscopy, infrared spectroscopy and X-ray photoelectron spectroscopy measurements confirmed the existence of the PGBHA-afGQDs film doped by MnO〈sub〉2〈/sub〉 NCs on the GCE surface. The charge transfer on this chemically modified electrode could be well achieved, which was revealed by the cyclic voltammetry and electrochemical impedance spectroscopy. The prepared electrochemical sensor was employed for the simultaneous determination of vitamin B2 (V〈sub〉B2〈/sub〉) and dopamine (DA) by using differential pulse voltammetry. The linear detection range of V〈sub〉B2〈/sub〉 and DA was obtained from 0.1 to 100 μM under the optimized conditions and the detection limits were measured to be 0.04 μM and 0.05 μM, respectively.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719306284-ga1.jpg" width="212" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Yaxiong Ji, Hong Zhong, Ping Chen, Xu Xu, Yuanhao Wang, Hai Wang, Guangyan Liu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The superiority of asymmetric gemini surfactant over the symmetric one is unveiled in case of organo-vermiculite (organo-Vt) for the first time. A common asymmetric gemini surfactant [C〈sub〉22〈/sub〉H〈sub〉45〈/sub〉(CH〈sub〉3〈/sub〉)〈sub〉2〈/sub〉N〈sup〉+〈/sup〉(CH〈sub〉2〈/sub〉)〈sub〉2〈/sub〉N〈sup〉+〈/sup〉(CH〈sub〉3〈/sub〉)〈sub〉2〈/sub〉C〈sub〉10〈/sub〉H〈sub〉21〈/sub〉]Br〈sub〉2〈/sub〉 (marked as 22-2-10) was adopted as modifier onto the vermiculite (Vt) to prepare adsorbent targeted at methyl orange (MO) and 〈em〉p〈/em〉-chlorophenol (PCP) in single and/or binary systems. The superiority of surfactant asymmetry on the structure of organo-Vt adsorbents was disclosed by larger interlayer spacing, more modifier loading, higher surfactant availability as well as the stronger adsorption capacity of organo-Vt modified by 22-2-10 (22-2-10-Vt) compared with organo-Vt modified by the corresponding symmetric modifier [C〈sub〉16〈/sub〉H〈sub〉33〈/sub〉(CH〈sub〉3〈/sub〉)〈sub〉2〈/sub〉N〈sup〉+〈/sup〉(CH〈sub〉2〈/sub〉)〈sub〉2〈/sub〉N〈sup〉+〈/sup〉(CH〈sub〉3〈/sub〉)〈sub〉2〈/sub〉C〈sub〉16〈/sub〉H〈sub〉33〈/sub〉]Br〈sub〉2〈/sub〉 (16-2-16-Vt). Effective retention of MO (142 mg g〈sup〉−1〈/sup〉) and PCP (85 mg g〈sup〉−1〈/sup〉) in single system were fitted by the pseudo-second-order, Langmuir and intra-particle diffusion models. Particularly, organic-matter-corrected sorption coefficient (〈em〉K〈sub〉OM〈/sub〉〈/em〉) was introduced to verify the partition process, which was found dominant in the adsorption processes and further promoted by hydrogen bond, intermolecular interaction and π-π interactions. The practical feasibility of 22-2-10-Vt was achieved in binary system, where the total adsorbate retention (0.74 mmol g〈sup〉-1〈/sup〉) was higher than that in single systems (0.54 or 0.31 mmol g〈sup〉-1〈/sup〉 for MO and PCP, respectively). An orderly gradient adsorption process was proposed in the binary system due to the stronger hydrophobicity of MO than PCP. The adsorbed adsorbents were regenerated by ethanol at least for three cycles in binary systems. The results obtained could not only throw lights on asymmetric modifiers and the related analogues, but also extend to the feasibility of organo-Vts in the multi-component water environment.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307289-ga1.jpg" width="348" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Peng Sun, Linfeng Li, Shanyi Guang, Hongyao Xu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In order to study the effect of dipole-dipole action direction and molecular space configuration on supramolecular self-assembly of azobenzene, three azobenzene dye molecules N1 (" linear "), N2 (" L ") and N3 (" U ") were designed. First, the feasibility of molecular design is verified by theoretical calculations and then synthesized by experiments. By adjusting the direction of the molecular dipole moment and the spatial configuration of the molecule, the three dye molecules self-assemble to form supramolecular self-assemblers with different structures. The properties of three azobenzene dye molecules were studied by IR、NMR、 X-ray diffraction and UV–vis spectra. Theoretical calculation and experimental results show that the direction of dipole dipole interaction and molecular space configuration have important effects on the supramolecular self-assembly morphology of azobenzene.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307307-ga1.jpg" width="213" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Elhamolsadat Ghorbi, Mehrnoush Namavar, Vahideh Rashedi, Saeideh Farhadinejad, Siamak Pilban Jahromi, Mohsen Zareian〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The study investigated influence of copper oxide nanoparticle (CuO NP) concentrations on the bactericidal properties of silver-copper oxide (Ag/CuO) nanocomposite against 〈em〉Escherichia coli〈/em〉 PTCC 1329, 〈em〉Klebsiella pneumoniae〈/em〉 PTCC 1290 and 〈em〉Staphylococcus aureus〈/em〉 PTCC 1189. Silver–copper oxide nanocomposite with varying concentrations of CuO was synthesized using a facile sol–gel combustion route. Formation of Ag/CuO crystalline structure and particle size were characterized by X-ray diffraction, Transmission Electron Microscopy and Field Emission Scanning Electron Microscopy. Elemental analyses were performed by energy dispersive X-ray. Morphologies of CuO NPs showed that Ag/CuO nanocomposite consisted of interconnected nanoparticles with a porous channel. Ag/CuO nanocomposite with higher CuO NPs content exhibited superior bactericidal effects. Bacterial growth profile also confirmed superior bactericidal effects of the nanocomposite at higher CuO NPs concentrations. A facile sol–gel technique with enhanced bactericidal effects at higher concentration of CuO NPs is promising for the development of cost-effective and efficacy-enhanced nanomaterials.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307204-ga1.jpg" width="363" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Keigo Tashiro, Suzuko Yamazaki〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We fabricated 5,10,15,20-tetra(4-pyridyl)porphyrinatozinc(II) (ZnTPyP) fibers by utilizing surfactant-assisted method with cetyltrimethylammonium bromide (CTAB). The ZnTPyP fibers became longer as molar ratio of CTAB to ZnTPyP (γ) increased. In the case of γ ≥ 50, the Soret band of ZnTPyP monomer was observed after stirring for 1 h and was split into two peaks after the aging at 40 °C for more than 5 days. On the other hand, such split peaks were observed without the aging when the γ value was 10 or 20. These findings suggest that CTAB interacts with the ZnTPyP monomer in aqueous solution to form micelles, and the fibers are gradually constructed by self-assembling the stabilized ZnTPyP monomer. Photocatalytic activity of the ZnTPyP fibers was evaluated for the degradation of rhodamine B (RhB) in water under visible light (VL) irradiation. The highest photocatalytic activity was obtained at γ = 150–300, indicating that the fibers with 1.3–2.0 μm were the most suitable as photocatalyst. When air was bubbled in the reaction solution, the photocatalytic activity was higher than that under N〈sub〉2〈/sub〉 bubbling. However, absorption peak attributed to the ZnTPyP fibers decreased under air bubbling although it remained almost constant under N〈sub〉2〈/sub〉 bubbling. These results suggest that the ZnTPyP fibers can act as photocatalyst and active oxygen species such as O〈sub〉2〈/sub〉〈sup〉•−〈/sup〉 radical might decompose the ZnTPyP fibers. Kinetic studies were performed to clarify the degradation mechanism of RhB under the experimental condition where the decomposition of the ZnTPyP fibers was negligible.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307290-ga1.jpg" width="368" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 580〈/p〉 〈p〉Author(s): Helena M. Heidemann, Marta E.R. Dotto, João B. Laurindo, Bruno A.M. Carciofi, Cristiane Costa〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Since starch hydrophilicity makes it difficult to be used as packaging material, its combination with synthetic biodegradable polymers is an alternative of interest. In this work, atmospheric air cold plasma was used as an adhesion improver between polycaprolactone (PCL) or poly(lactic acid) (PLA) and starch layers, in order to produce multilayer films. For this, a barrier dielectric discharge plasma reactor was used, at ambient temperature and atmospheric pressure. The treatment of PCL and PLA films resulted in increase of the surface roughness and decrease of the water contact angle. Multilayer films (PCL-, PLA-starch) were produced after plasma treatment. Adhesion of starch films onto both PCL and PLA surfaces was improved with plasma treatment, and the delamination resistance increased with treatment time. The best adhesion was obtained for PLA-starch film with 10 min of plasma treatment, resulting in no delamination. The water vapor barrier of the multilayer films was significantly higher than of starch films, while the mechanical properties were similar to those found for PCL/PLA films, showing that these multilayer films are promising for package applications.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719307277-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 29 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Md. Obaidullah, Newaz Mohammed Bahadur, Takeshi Furusawa, Masahide Sato, Hiroshi Sakuma, Noboru Suzuki〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 nanoparticles (NPs) coated by the SiO〈sub〉2〈/sub〉 shell with a thickness up to˜6.5 nm were synthesized by a fast and facile microwave irradiation approach. The thickness of the SiO〈sub〉2〈/sub〉 shell around Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 NPs could be controlled by varying tetraethoxysilane (TEOS) concentration as well as avoiding individual SiO〈sub〉2〈/sub〉 particle formation. The synthesized Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉@SiO〈sub〉2〈/sub〉 core-shell nanocomposites (NCs) were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy dispersive X-ray (EDX) spectroscopy. The bigger particle size compared to the uncoated Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 NPs and Si − O–Si asymmetric stretching vibrational band at 1101 cm〈sup〉-1〈/sup〉 in the prepared NCs obtained by FE-SEM and FT-IR study, respectively anticipated the successful SiO〈sub〉2〈/sub〉 coating on Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 NPs. The presence of homogeneous silica layer was authenticated by TEM observation. The change in binding energy of Fe 2p3 and Si 2p in the synthesized NCs compared to the uncoated Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 and pure SiO〈sub〉2〈/sub〉 NPs corroborated the formation of Fe − O–Si bond at the interface of Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 (core) and SiO〈sub〉2〈/sub〉 (shell). The existence of magnetic property in the prepared NCs, even above the Curie temperature of Fe〈sub〉2〈/sub〉O〈sub〉3〈/sub〉, was assured by vibrating sample magnetometer (VSM) study. This observation will undoubtedly inspire to design and fabricate novel heterostructures of iron oxide to retain its magnetization at high temperature.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719302626-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 28 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Negin Kananizadeh, Jaewoong Lee, Ehsan S. Mousavi, Keith B. Rodenhausen, Derek Sekora, Mathias Schubert, Shannon Bartelt-Hunt, Eva Schubert, Jianmin Zhang, Yusong Li〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Understanding the influence of surface roughness on the deposition of nanoparticles is important to a variety of environmental and industrial processes. In this work, slanted columnar thin films (SCTFs) were engineered to serve as an analogue for rough surfaces with controlled height and surface properties. The deposition of titanium dioxide nanoparticles (TiO〈sub〉2〈/sub〉NPs) onto alumina- or silica-coated SCTFs (Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉-Si-SCTF, SiO〈sub〉2〈/sub〉-Si-SCTF) with varying heights (50 nm, 100 nm, and 200 nm) was measured using a combined quartz crystal microbalance with dissipation monitoring (QCM-D) and generalized ellipsometry (GE) technique. No TiO〈sub〉2〈/sub〉NP deposition was observed on flat, silica-coated QCM-D sensors or rough, 100 nm thick SiO〈sub〉2〈/sub〉-Si-SCTF. TiO〈sub〉2〈/sub〉NP deposition onto Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉-Si-SCTFs in ultra-pure water was significantly higher than on the flat alumina-coated QCM-D sensor, and deposition increased as the roughness height increased. The nanoparticle attachment was sensitive to the local flow field and the interaction energy between nanoparticles and the QCM-D sensor. At a higher ionic strength condition (100 mM NaCl), TiO〈sub〉2〈/sub〉NP aggregates with varying sizes formed a rigid layer on top of SCTFs. For the first time, deposition of nanoparticles was measured as a function of roughness height, and the impact of roughness on the properties of the attached nanoparticle layers was revealed. This finding indicates that key parameters describing surface roughness should be explicitly included into models to accurately predict the transport of nanoparticles in the subsurface.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719302894-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 28 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Jean C. Villamil, Claudia M. Parra-Giraldo, León D. Pérez〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Amphotericin B (AmB) is an antifungal drug with a broad spectrum of action. It has few resistance reports, and it is widely used for treating invasive fungal infections. However, it has many drawbacks related to its administration and undesired side effects, such as nephrotoxicity. The use of polymer micelles not only increases the solubility of AmB in aqueous media, but also attenuates its toxicity. Nevertheless, polymer micelles have low loading capacities because they interact weakly with AmB, which is an amphiphilic and amphoteric molecule. In the present research, we investigate the effect of conjugating mPEG-b-PCL with cholesterol. This is a biocompatible and biodegradable block copolymer commonly used as a drug carrier. The results indicated that the presence of cholesterol increased the encapsulation efficiency and loading capacity of AmB, and improves their ability to impart controlled release. Compared with Fungizone® as reference, AmB-loaded polymer micelles presented lower 〈em〉in vitro〈/em〉 efficacy against 〈em〉Candida albicans SC5314〈/em〉, and this was seen as an increase in minimum inhibitory concentration. However, 〈em〉in vivo〈/em〉 assessment of antifungal activity using an invertebrate 〈em〉Galleria mellonella〈/em〉 model for invasive candidiasis showed comparable efficacy. The toxicity of AmB against red blood cells was attenuated upon encapsulation. The results indicated that in addition to the favourable interaction of AmB–micelle core from the presence of cholesterol, a synergistic effect was found with the segment of PCL, thereby resulting in improved performance.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719302870-ga1.jpg" width="268" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 28 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Jae Kyeong Han, Jae Yun Lee, Hyoung Jin Choi〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Spinel ferrite nanoparticles with enhanced magnetism were prepared by non-stoichiometric doping of Zn cation to magnetite and adopted as an additive into carbonyl iron (CI)-based magnetorheological (MR) suspension, with the expectation of improved MR effect and suspension stability. Rheological characteristics of the MR fluids both with and without an additive were analyzed using a rotational rheometer. The addition of 0.5 wt% Zn-doped ferrite (Zn〈sub〉x〈/sub〉Fe〈sub〉3-x〈/sub〉O〈sub〉4〈/sub〉) to the MR fluid enhanced not only the MR performance but also sedimentation stability, as confirmed by Turbiscan. The nanoparticles of truncated octahedron-like shape were thought to be inserted into the free volume between microparticles.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719302857-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈p〉Non-stoichiometric Zn-doped ferrite nanoparticles were used as the additive onto CI based MR suspensions, and then their rheological and dispersive effects were investigated using a rotational rheometer and optical measurements.〈/p〉 〈/div〉

Description: 〈p〉Publication date: Available online 29 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Frank Rhein, Felix Ruß, Hermann Nirschl〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The main goal of this work is to develop and validate a new method for characterizing the material properties of hetero-agglomerates when calculating population balances in magnetic seeded filtration processes. A new approach of computing various collision cases and probabilities and then weighting the respective agglomeration rates with them is considered to be physically justifiable. An experimental design of experiment (DOE) yielded data for the variation of multiple process parameters with a reasonable standard deviation. 〈strong〉By measuring agglomeration kinetics, a deeper understanding of the process could be achieved and simple mathematical models were found in order to describe experimental data.〈/strong〉 The following multiple regression analysis showed good accordance with the agglomeration theory and thus the data was usable for further validation of the calculation results. By comparing calculated and experimental data and minimizing the residuals, estimates of the model parameters describing hard-to-measure material properties could be obtained. The comparison of experimental and computational regression models showed good agreement and thus validates the fundamental physical soundness of the implemented model. Furthermore, the comparison of the measured and calculated agglomeration kinetics further suggests the validity of the collision case model. Finally, this work showcases the possibilities of additional model calculations for a deeper, more thorough process understanding.〈/p〉〈/div〉 〈div〉 〈h6〉Graphical abstract〈/h6〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719302900-fx1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: Available online 28 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): K. Wiercigroch-Walkosz, J. Cichos, M. Karbowiak〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The method based on the oil/water biphasic system appears as the most effective for the growth of mesoporosus silica shell on hydrophobic nanocrystals. In this paper the influence of various synthesis parameters, such as catalyst, solvent, temperature or hydrophobic chain length of surfactant, on porosity and thickness of silica layer grown on up-converting nanocrystals (UCNPs) was systematically investigated. The key factor determining morphology of silica shell and allowing to control its porosity is a kind of solvent used for TEOS dilution. For solvents of low polarity index silica shell has dendrimeric structure with pore size of 4–5.5 nm, while for solvents with high polarity index the silica shell is non-porous. The pore size can be also controlled in the range from 2 to 5.5 nm through selection the catalysts type. The morphology of the silica shell is also influenced by alkyl chain length of the cationic surfactant as well as temperature. Based on these new experimental results the mechanism of formation of mesoporous silica shell on inorganic nanopaticles was proposed and discussed. It was also proved, that the organic dyes, like Rhodamine B can be effectively incorporated inside the pores of mesoporous UCNPs@SiO〈sub〉2〈/sub〉 nanoparticles. This signify that such hybrid functional materials, which in addition exhibit stability of water dispersions and possibility of biofunctionalization, offer great potential for development of biomarkers or drug carriers.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719300603-ga1.jpg" width="261" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 28 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Mengke Wang, Zhaozhu Zhang, Yanling Wang, Xin Zhao, Mingming Yang, Xuehu Men〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Separation of oily waste water and emulsified water/oil mixtures has gained much social attention due to the increasing emission of industrial waste water and sanitary sewage. However, endowing a material with the capacity of separating multiple immiscible water/oil mixtures and emulsified water-in-oil/oil-in-water mixtures is still challengeable but urgently desirable. Herein, a universal layer-by-layer assembly method utilizing the electrostatic attraction between polyethyleneimine (PEI) and SiO〈sub〉2〈/sub〉 nanoparticles has been adopted in fabricating superwetting materials regardless of the substrates. The as-prepared materials which possess both superhydrophilicity/underwater superoleophobicity and superoleophilicity/underoil superhydrophobicity present high separation capability without any pre-wetting treatment towards various water/oil mixtures, including water/heavy oil mixtures, water/light oil mixtures, water-in-oil emulsions and oil-in-water emulsions. Significantly, the addition of (3-Glycidyloxypropyl) trimethoxysilane (KH-560) acting as a crosslinking agent with PEI endues as-prepared materials excellent durability and chemical stability in cyclic separations and extreme environments, respectively. Benefitting from the universality and substrate-independency of LbL-assembly, the method adopted in this paper could satisfy multiple demands of industry by applying on desirable substrates.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719302808-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 29 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Masumeh Foroutan, Hojat Zahedi, Ebrahim Soleimani〈/p〉

Description: 〈p〉Publication date: Available online 27 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Xueqian Guan, Zhiyu Huang, Pengxiao Fang, Hongsheng Lu, Dejun Sun〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Similar to the responsive behaviors of emulsions under salt-free conditions, precise control of emulsification and demulsification is also required in some applications under saline conditions, especially in crude oil production and transport. So far, few studies have focused on the preparation of the responsive emulsions under saline conditions. In this study, CO〈sub〉2〈/sub〉 responsive emulsions were prepared in the presence of NaCl using a fatty acid soap M-DA as stabilizer. M-DA complex was synthesized through electrostatic interactions between dimeric acid (DA) and Jeffamine (M1000). The droplet size and morphology of the oil–brine emulsions were characterized by dynamic light scattering and transmission electron microscopy, respectively. The oil–brine emulsion maintains high stability under air but completely separates into two phases upon exposure to CO〈sub〉2〈/sub〉. NaCl plays a significant role in the CO〈sub〉2〈/sub〉-induced demulsification, including salting-out effect and screening of electrostatic repulsion. It is worth noting that in the absence of NaCl, the emulsion remained stable after CO〈sub〉2〈/sub〉 bubbling. CO〈sub〉2〈/sub〉 responsive emulsions can also be prepared in the presence of other salts, or with other fatty acid soaps, which presents more interesting possibilities for preparation of CO〈sub〉2〈/sub〉 responsive emulsions under saline conditions.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719302845-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 27 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Chuanglei Fan, Nan Chen, Chuanping Feng, Yuqing Yang, Jibo Qin, Miao Li, Yu Gao〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The removal of pollutants from water using agricultural waste-based biomaterials is gaining extensive attention. In this study, biochar loading ruthenium oxide (RuO〈sub〉2〈/sub〉/BC), a novel composite for bromate removal from drinking water, has been prepared by the impregnation method. Based on the single-factor design, a Box-Behnken design (BBD) of the response surface methodology (RSM) was applied to access the mutual interactions and effects between the three factors and optimized preparation conditions (activation time is 3.9 h, activation temperature is 612.2 °C and mass ratio of biochar to RuCl〈sub〉3〈/sub〉 is 38.9: 1). The effects of initial solution pH, RuO〈sub〉2〈/sub〉/BC dosage and initial bromate concentration on bromate removal by RuO〈sub〉2〈/sub〉/BC were investigated. The Field Emission Scanning Electronic Microscopy (FESEM), Brunauer-Emmett-Teller (BET), Energy Dispersive X-Ray Spectroscopy (EDS), X-ray Photoelectron Spectroscopy (XPS) and Zeta potential were used to characterize the properties of prepared composite. Results showed that bromate removal by RuO〈sub〉2〈/sub〉/BC was highly pH dependent and the bromate reduction kinetics followed the pseudo-first-order kinetic model. The detailed mechanism including adsorption and reduction of bromate by the synergistic effect of RuO〈sub〉2〈/sub〉 and biochar (C = C, C = O and -OH) was demonstrated. These results proposed a new approach for the remediation of bromate contaminated water.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719302821-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 28 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Weifang Chen, Yaning Zong, Yi Zhou, Weipeng Lu, Yue Zhang, Jiacheng Qian〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As one of the hard templating method for making porous materials, MgO templating was under intensive investigation for its various advantages. In this research, MgO templating was employed to reuse textile waste cotton. The main purpose was to compare the pyrolysis behaviors of four MgO-precursors (magenesium acetate, magnesium chloride, magnesium citrate and MgO particles) for their effectiveness as templating agents. Thermogravimetric and X-ray diffraction analysis showed that precursors decomposed stepwise or disintegrate to form nano-size MgO particles. At the same time, carbonized cotton was able to replicate the morphology of MgO particles to create porous structures. The effects of precursor and treatment temperature on the morphology of MgO, pore structures and surface chemistry were investigated. Results proved that by manipulating templating conditions, cotton waste was able to produce activated carbon of various properties.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719302924-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈p〉TG analysis of MgO-precursor impregnated cotton.〈/p〉 〈/div〉

Description: 〈p〉Publication date: 20 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 565〈/p〉 〈p〉Author(s): Kunlin Chen, Jianlin Zhou, Fangqing Ge, Run Zhao, Chaoxia Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Fabrication of smart fabrics using a simple and scalable method is a big challenge, and this paper is aimed at developing a facile approach for the preparation of smart fabric coatings. The coating was formed on the fabric using pH-responsive polyurethane (pH-PU) and fluorated octavinyl polyhedral oligomeric silsesquioxane (F-OV-POSS) by UV curing. These obtained fabric coatings exhibited durable superhydrophobicity and self-cleaning ability even under some harsh environments, such as mechanically damaged, seawater and UV-irradiation. Due to the protonation and deprotonation of the pH-PU along with the changing of pH value, the wettability of fabric coating could be changed between the superhydrophobicity and underwater superoleophobicity by regulating pH value, and oil or water is able to be separated from an oil/water mixture. In addition, the damaged fabric coatings could restore their special wettability through simply heating, because fluorocarbon chains of F-OV-POSS in the coatings easily migrated to the outer surface of coatings. It is expected that this smart self-healing fabric coating with durable self-cleaning and oil/water separating performance would be a good case for practical applications in energy saving and sustainable development.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718315644-ga1.jpg" width="395" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 565〈/p〉 〈p〉Author(s): Maria G. Chernysheva, Andrey G. Popov, Vadim N. Tashlitsky, Gennadii A. Badun〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Given the unique properties of nanodiamonds, such as biocompatibility, low cytotoxicity and high adsorption capacity, this material is considered to have potential in drug delivery platforms. In this study, we tested nanodiamonds with different surface properties in relation to quaternary ammonium surfactant (Myramistin). For all tested materials that possess positive and negative zeta potential adsorption of surfactants on the surface of nanodiamonds, aggregates in the aqueous suspension are described by the Langmuir adsorption equation.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718317631-ga1.jpg" width="356" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 565〈/p〉 〈p〉Author(s): Hidetaka Ueno, Masatoshi Inoue, Atsuhito Okonogi, Hidetoshi Kotera, Takaaki Suzuki〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Cell surface reactions such as material surface characteristics and cell proliferation/adhesion rates are correlated and this correlation can be used as early determination criteria for shortening the development period and reducing costs of selecting materials used for bio-experiments, and of bio-experimental instruments. When fabricating Cells-on-Chips, a microfluidic device fabricated using MEMS technology, the influence of the scaffold material should be considered. Since a wide variety of materials are used as constituent materials of Cells-on-Chips, highly versatile early determination criteria corresponding to a specific environment and various materials are needed. In this research, we propose the early determination criteria of scaffolding material composing Cells-on-Chips by using surface free energy, which is calculated from contact angle that can be measured easily and inexpensively. Six materials were selected, regardless of inorganic/organic and photosensitive/non-photosensitive properties. When HeLa cells were cultured on each material, a significant correlation was observed between surface free energy and cell proliferation/adhesion rates. Therefore, the surface free energy of the material is appropriate as the early determination criteria for selecting the constituent material of Cells-on-Chips. Compared with the conventional criteria, the proposed criteria have high versatility regardless of the kind of material and can be used for evaluation of various materials.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718317655-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 565〈/p〉 〈p〉Author(s): Juan Liu, Jianan Cui, Tianyu Zhao, Siyang Fan, Conglu Zhang, Qi Hu, Xiaohong Hou〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-CeO〈sub〉2〈/sub〉/activated carbon (AC) composite was synthesized by an immersion-precipitation process. The Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-CeO〈sub〉2〈/sub〉/AC composite was characterized by BET surface area measurement, Fourier Transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopic (XPS), and vibrating sample magnetometer (VSM). Its catalytic activity was evaluated by azo organic dye Orange G (OG) oxidation in heterogeneous Fenton system. Due to excellent performance of AC in adsorption and conductivity, the catalyst exhibited enhanced catalytic activity compared with AC-Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉, CeO〈sub〉2〈/sub〉-AC, Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-CeO〈sub〉2〈/sub〉 and AC. Some parameters, such as initial concentration of OG, pH, catalyst loading, H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 dosage, were studied. At pH 2.5, H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 18 mM, OG 50 mg L〈sup〉−1〈/sup〉, Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-CeO〈sub〉2〈/sub〉/AC 0.4 g L〈sup〉−1〈/sup〉 and 35 °C, the OG removal rate and the total organic carbon (TOC) removal reached 98.8% and 56.3% within 60 min. The stability and reusability of the Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-CeO〈sub〉2〈/sub〉/AC were also tested. Besides a possible OG degradation pathway was proposed and eight intermediates were determined.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718316327-ga1.jpg" width="490" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 565〈/p〉 〈p〉Author(s): Mittal L. Desai, Hirakendu Basu, Rakesh Kumar Singhal, Sudeshna Saha, Suresh Kumar Kailasa〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The present work offers a new exploration for the selective sensing of metal ions (Ag〈sup〉+〈/sup〉 and Mn〈sup〉2+〈/sup〉) via fluorescence quenching of Ti〈sub〉3〈/sub〉C〈sub〉2〈/sub〉 MXene nanosheets (NSs). Monolayer MXene Ti〈sub〉3〈/sub〉C〈sub〉2〈/sub〉 NSs exhibited excellent ability to sense Ag〈sup〉+〈/sup〉 and Mn〈sup〉2+〈/sup〉 ions because of their good hydrophilicity and distinctive surface functionality. The as-synthesised Ti〈sub〉3〈/sub〉C〈sub〉2〈/sub〉 NSs exhibited highest emission fluorescence peak at 461 nm upon the excitation wavelength of 384 nm. The fluorescence emission peak of Ti〈sub〉3〈/sub〉C〈sub〉2〈/sub〉 NSs was remarkably quenched only upon the addition of Ag〈sup〉+〈/sup〉 and Mn〈sup〉2+〈/sup〉 ions, exhibiting good linear response between I〈sub〉0〈/sub〉/I and concentration in the range of 0.1–40 μM and 0.5–60 μM for Ag〈sup〉+〈/sup〉 and Mn〈sup〉2+〈/sup〉 ions. The proposed sensor shows lower detection limits of 9.7 and 102 nM for Ag〈sup〉+〈/sup〉 and Mn〈sup〉2+〈/sup〉 ions with good selectivity. Additionally, the method is effectively applied to detect Ag〈sup〉+〈/sup〉 and Mn〈sup〉2+〈/sup〉 ions in food and real water samples with excellent recoveries.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718312986-ga1.jpg" width="343" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 565〈/p〉 〈p〉Author(s): N. Gayathri Menon, Sankara Sarma V. Tatiparti, Suparna Mukherji〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The effect of ZnO content in TiO〈sub〉2〈/sub〉-ZnO nanocomposites synthesized via sol-gel route was studied by varying the Ti:Zn molar ratios from 1:0.1 (TZ-1:0.1) to 1:1 (TZ-1:1). Phase transformation of anatase TiO〈sub〉2〈/sub〉 to rutile and the ultimate formation of mixed oxides at the expense of rutile TiO〈sub〉2〈/sub〉 and ZnO (ZnTiO〈sub〉3〈/sub〉 and Zn〈sub〉2〈/sub〉TiO〈sub〉4〈/sub〉) were observed to occur in a Zn concentration dependent manner at a constant calcination temperature of 600 °C for 1 h. These phase transformations were concomitent with alterations in morphology and bandgap. Zn addition into the nanocomposites facilitated visible light activity at all the Ti:Zn molar ratios studied. Superior visible light photocatalytic decolorization of methyl orange dye, was observed in nanocomposites TZ-1:0.3 (Ti:Zn of 1:0.3) and TZ-1:0.4 (Ti:Zn of 1:0.4) that contained a blend of phases, predominated by rutile TiO〈sub〉2〈/sub〉 and ZnTiO〈sub〉3〈/sub〉 and not by the anatase phase. Analysis of reaction rate by fitting decolorization kinetics into the Langmuir – Hinshelwood model revealed that rate of decolorization under visible irradiation was significantly higher in TZ-1:0.4 (Langmuir-Hinshelwood rate constant, k〈sub〉LH〈/sub〉 of 6.8 × 10〈sup〉−2〈/sup〉 min〈sup〉-1〈/sup〉) than in TZ-1:0.3 (k〈sub〉LH〈/sub〉 of 5.3 × 10〈sup〉−2〈/sup〉 min〈sup〉-1〈/sup〉). However, the nanocomposite TZ-1:0.3 promoted greater extent of mineralization compared to TZ-1:0.4. Addition of Zn not only helped in tailoring the bandgap of the nanocomposites for facilitating visible light activity, it also affected photocatalytic decolorization and/or mineralization of methyl orange dye under both UV and visible irradiation by controlling the unique blend of phases existing in the nanocomposite.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718316303-ga1.jpg" width="360" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 567〈/p〉 〈p〉Author(s): Xinquan Zou, Hong Zhang, Tao Chen, Huitao Li, Chihan Meng, Ying Xia, Jing Guo〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel polyacrylamide (PAM) / sodium alginate (SA) adsorbent with double network structure was prepared by emulsion polymerization of acrylamide (AM) and SA. The chemical structure, thermal stability, crystallinity, pore size and distribution, surface area, surface morphology and energy dispersive spectrum of PAM/SA microspheres were determined by FTIR, TGA, XRD, BET, SEM and EDS. In addition, the effects of pH, temperature and adsorbent dosage on the adsorption capacity of Methylene blue (MB) were evaluated. The adsorption isotherms and kinetics as well as the thermodynamics of adsorption process were also studied. The results show that due to the entanglements between PAM and SA molecular chains. A double network structure is formed. The introduction of SA leads to the decrease of thermal stability and crystallization ability of PAM. The pore size is in the range of 0–200 nm, and the mesoporous structure is uniform. The particle size of is in the range of 1–10 u m. The surface of PAM/SA composite microspheres is smooth, and the ion crosslinking point is uniformly distributed. The results show that when pH=6, temperature is 25℃ and adsorbent dosage is 0.1g, the maximum adsorption capacity of PAM/SA composite microspheres is 75 mg/g. Langmuir isothermal model has better correlation with MB adsorption, and the maximum capacity obtained by simulation is 1070.54 mg/g. The pseudo-first-order kinetics and adsorption thermodynamics are better. The adsorption process is a physical adsorption rather than the chemical interation. The adsorption force decreases with the increase of temperature. The obtained PAM / SA composite microspheres have excellent adsorption capacity for dye removal from wastewater.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718308148-ga1.jpg" width="370" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈p〉Schematic illustration of the group bond points as well as the reaction apparatus used in inverse emulsion polymerization.〈/p〉 〈/div〉

Description: 〈p〉Publication date: 5 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 566〈/p〉 〈p〉Author(s): Lykke Stounbjerg, Christian Vestergaard, Birgitte Andreasen, Richard Ipsen〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Plant proteins are receiving growing interest from the food and beverage industry. However, the properties of these proteins are still insufficiently characterised. The present study investigated the associative phase separation between potato protein (PP) isolate and anionic polysaccharides (PS), namely alginate (ALG), carboxymethylcellulose (CMC), and gum arabic (GA) to further the understanding of interactions between PP and commonly used PS with potential applications in the food industry. Through biopolymer titration and acidification, the effect of PP–PS mixing ratio (0.1-5:1, at 0.1 wt%) and pH (9-3) was investigated. The complexation process was characterised on micro- and macroscale by turbidimetry, electrophoretic light scattering, isothermal calorimetry, and precipitate composition was analysed. Turbidity measurements showed that ALG, CMC, and GA were saturated with PP at ratios of 5:1, 3:1, and 2:1, respectively. Isothermal calorimetry measurements confirmed that there was no additional binding at higher mixing ratios. Turbidimetry also indicated that PP and PS formed soluble complexes above pI, at highly alkaline pH. ALG, possessing the highest electrostatic charge density, yielded the most pronounced enthalpy change upon addition of PP, indicating more heat was released by the electrostatic complexation compared to GA and CMC. This could explain the resultant highest PP binding capacity and a precipitate that did not dissociate at low pH. At certain mixing ratios, PP and GA formed micro-dispersions, while complexing with ALG or CMC predominantly resulted in soluble complexes or insoluble precipitate. During acidification, the charges of the complexes followed the trend of PS instead of PP, suggesting the PP was internalised in the complexes.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719300081-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 566〈/p〉 〈p〉Author(s): Gang Yu, Kuo Han, Jing Wang, Xiao Cheng, Hongmei Ma, Hongya Wu, Zhigang Yang, Guanglei Zhang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In the present work, the activated carbon fibers (ACFs) with homogenous and crystalline CeO〈sub〉2〈/sub〉-ZrO〈sub〉2〈/sub〉 coatings were obtained using a facile water steam treatment process at a low temperature (300 °C) for efficient removal of Pb(II) from aqueous solutions. The morphology, surface chemical states, and adsorption performance were studied extensively. Results demonstrated that the steam-treated CeO〈sub〉2〈/sub〉-ZrO〈sub〉2〈/sub〉/ACFs possessed superior high surface areas (783.23 m〈sup〉2〈/sup〉 g〈sup〉−1〈/sup〉) and pore volumes (0.41 cm〈sup〉3〈/sup〉 g〈sup〉−1〈/sup〉). Moreover, numerous C-O-M bonds formed in the interface between CeO〈sub〉2〈/sub〉-ZrO〈sub〉2〈/sub〉 coatings and ACFs, which can endow the adsorbent desired mechanical property and service durability as well as many surface hydroxyl groups were found and adsorption capacity (61.54 mg g〈sup〉−1〈/sup〉 at pH 6.5 ± 0.3 and 25 °C). It was suggested that the steam-treated CeO〈sub〉2〈/sub〉-ZrO〈sub〉2〈/sub〉/ACFs could be considered as a promising adsorbent towards wastewater treatment.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719300093-ga1.jpg" width="234" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 566〈/p〉 〈p〉Author(s): Evgenii Velichko, Bei Tian, Tatiana Nikolaeva, Jeroen Koning, John van Duynhoven, Wim G. Bouwman〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A versatile cell for X-ray and neutron scattering experiments on samples under shear has been designed. To our knowledge, it is the first shear cell which can be used for both SAXS and SANS in respectively synchrotron or reactor beamlines. The cell is mainly intended for scattering experiments in so-called “1–2 plane geometry”, but can also be modified into cone–plate and plate–plate rheological geometries, giving access to the 1–3 scattering plane. The latter two geometries, however, can only be used with neutron scattering. The final cell design is compact, which allows it to be used even with lab-based X-ray sources. A special thermostatic shell allows for the temperature control of the samples under investigation in the range from 5 up to 100 °C. Several X-ray and neutron scattering experiments performed with the cell have helped in better understanding of the structuring under shear of food materials, such as: cellulose suspensions, fat crystal networks and milk proteins.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718317588-ga1.jpg" width="302" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 565〈/p〉 〈p〉Author(s): Marcius A. Ullmann, Arthur A. Bernardes, João H.Z. dos Santos〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Cp〈sub〉2〈/sub〉ZrCl〈sub〉2〈/sub〉 was immobilized on silica by two methods: direct grafting (GS) and 〈em〉via〈/em〉 entrapment within silica matrix, produced by the non-hydrolytic sol-gel method (NH). In the latter case, the surface was further modified by metal salts (Cr, Mo and W). The supported catalysts (three GS and four NH systems) were evaluated in ethylene polymerization, having methylaluminoxane (MAO) as the cocatalyst. Almost all of them resisted to at least 0.2 μg g〈sup〉−1〈/sup〉 acetone (used as probe molecule for oxygenated poisons). NH systems bearing W or Mo (3 wt.%) on its structure were shown to be more productively efficient against poisoning. NH containing W in its structure tended to keep its catalyst activity even after the addition of the poison. Therefore, metal doping may be a suitable strategy to keep or increase the efficiency of entrapped zirconocene systems against oxygenated poisons. SAXS analyses show likewise that the smaller the primary spheres, the more protected will be the active site. Texture and microstructure of the catalytic systems and properties of the yielded polyethylenes reveal that the nature of the immobilization route affects the polymer properties (Mw and T〈sub〉m〈/sub〉).〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718317539-ga1.jpg" width="494" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 565〈/p〉 〈p〉Author(s): Nikolay O. Mchedlov-Petrossyan, Vladimir S. Farafonov, Tatyana A. Cheipesh, Sergey V. Shekhovtsov, Dmitry A. Nerukh, Alexander V. Lebed〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We report on combined experimental and theoretical investigations of the water/micelle interface of cationic, anionic, zwitterionic, and non-ionic surfactants using a new hydrophobic acid-base indicator 2,6-dinitro-4-〈em〉n〈/em〉-dodecylphenol. The indices of the so-called apparent ionization constant, 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si3.gif" overflow="scroll"〉〈mrow〉〈mtext〉p〈/mtext〉〈msubsup〉〈mi〉K〈/mi〉〈mtext〉a〈/mtext〉〈mtext〉app〈/mtext〉〈/msubsup〉〈/mrow〉〈/math〉, of the indicator fixed in the micellar pseudophase are determined by the spectrophotometric method. The data allows estimating the Stern layer’s electrostatic potential of the ionic micelles 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si5.gif" overflow="scroll"〉〈mi〉Ψ〈/mi〉〈/math〉. Molecular Dynamics modeling was used to locate the dye molecule and, in particular, its ionizing group OH→O〈sup〉–〈/sup〉 within the micelles of the studied surfactants. The comparison of the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si5.gif" overflow="scroll"〉〈mi〉Ψ〈/mi〉〈/math〉 values estimated using 2,6-dinitro-4-〈em〉n〈/em〉-dodecylphenol with both our computer simulation and literature experimental results reveals obstacles in monitoring electrical interfacial potentials. In particular, the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si5.gif" overflow="scroll"〉〈mi〉Ψ〈/mi〉〈/math〉 values of the surfactant micelles with alkylammonium groups determined via 2,6-dinitro-4-〈em〉n〈/em〉-dodecylphenol are overestimated. The reason is specific interactions of the indicator anion with the surfactant head groups. For anionic surfactants, however, this indicator is quite suitable, which is confirmed by the location of HA and A〈sup〉–〈/sup〉 equilibrium forms in the pseudophase.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718317606-ga1.jpg" width="234" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 565〈/p〉 〈p〉Author(s): Ahmed Nuri Kursunlu, Yaser Acikbas, Mustafa Ozmen, Matem Erdogan, Rifat Capan〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Here, a pillar[5]arene derivative including biphenylcarboxylic acid groups was designed for obtaining a macrocycle with an ideal cavity for volatile organic compounds. The pillar[5]arene -biphenylcarboxylic acid (〈strong〉P5-BPCA〈/strong〉) based Langmuir-Blodgett (LB) thin films were produced onto 50 nm thick gold-coated glass and 3.5 MHz quartz crystal substrates to form a thin film chemical sensor element. Surface plasmon resonance (SPR) and Quartz crystal microbalance (QCM) techniques were employed to characterize all the 〈strong〉P5-BPCA〈/strong〉 LB thin film layers. The mass of LB film layer loaded onto a quartz crystal and the resonance frequency shifts per layer were determined to be 711.71 ng per layer (2.68 ng mm〈sup〉−2〈/sup〉) and 48.24 Hz per layer, respectively. The 〈strong〉P5-BPCA〈/strong〉 LB thin film sensor element was exposed to various haloalkane and aromatic hydrocarbon vapors. The sensitivities of the 〈strong〉P5-BPCA〈/strong〉 LB film sensor were determined between 1.776 and 3.976 Hz ppm〈sup〉−1〈/sup〉. Sensitivity with detection limits were obtained between 0.754 and 1.689 ppm against organic vapors. The results showed that 〈strong〉P5-BPCA〈/strong〉 LB thin film was highly selective with a large response to chloromethane vapor.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉SPR kinetic study of 〈strong〉P5-BPCA〈/strong〉 LB thin film for chloromethane vapor.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718310483-ga1.jpg" width="232" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 20 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 565〈/p〉 〈p〉Author(s): Elvira Rozhina, Svetlana Batasheva, Marina Gomzikova, Ekaterina Naumenko, Rawil Fakhrullin〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We investigated the influence of halloysite nanotubes and magnetic nanoparticles stabilized by positively charged polyelectrolyte polyallyamine hydrochloride (PAH) on the built-up of multicellular spheroids using cancer and primary cell cultures. We found no adverse effects caused by the nanoparticles investigated on the formation of 3D cell structures. The use of magnetic nanoparticles (MNPs) has allowed controlling the spheroid spatial movement, which may find applications in cell biology, tissue engineering and nanomedicine. We have also shown for the first time that halloysite nanotubes do not affect the formation of spheroids, including those formed from mesenchymal stem cells.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775718309324-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 583〈/p〉 〈p〉Author(s): Diana R. Lima, Ahmad Hosseini-Bandegharaei, Pascal S. Thue, Eder C. Lima, Ytallo R.T. de Albuquerque, Glaydson S. dos Reis, Cibele S. Umpierres, Silvio L.P. Dias, Hai Nguyen Tran〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Activated carbons from Brazil nutshells were produced by ZnCl〈sub〉2〈/sub〉-activation at different biomass: ZnCl〈sub〉2〈/sub〉 ratios of 1.0:1.0 and 1.0:1.5 at 600 °C and the samples were denominated as BNS1.0 and BNS1.5, respectively. The obtained activated carbons were used in the adsorption of acetaminophen (paracetamol) and for the treatment of synthetic hospital effluents. Several analytical techniques were used to characterize the activated carbons. The N〈sub〉2〈/sub〉 isotherms presented the S〈sub〉BET〈/sub〉 values of the BNS1.0 and BNS1.5 are very high, 1457 and 1640 m〈sup〉2〈/sup〉 g〈sup〉−1〈/sup〉, respectively. The FTIR and Boehm titration analysis demonstrated the presence of several surface functional groups on both ACs surfaces, which can influence the acetaminophen adsorption. The adsorption studies revealed that the maximum adsorption capacities (Q〈sub〉max〈/sub〉) are very high for both ACs; however, the BNS1.5 capacity is higher (411.0 mg g〈sup〉−1〈/sup〉) than that of BNS1.0 (309.7 mg g〈sup〉−1〈/sup〉). The thermodynamic assessments revealed that the process of acetaminophen adsorption is spontaneous, energetically favorable, and exothermic, and the magnitude of enthalpy is compatible with physisorption. Besides, it suggests that the acetaminophen adsorption on both ACs is dominated by van der Walls forces and microporous filling mechanism. The use of activated carbons for treatment of synthetic hospital effluents, containing different pharmaceuticals as well as organics and inorganic salts, presented a high percentage of removal (up to 98.83%). The adsorbent was magnificently regenerated up to 74% with a mixture of 0.1 mol L〈sup〉−1〈/sup〉 NaOH + 20% EtOH solution and can be reused up to four cycles ensuring sustainable use of proposed adsorbent for acetaminophen removal from aqueous media. In the light of these results, it is possible to say that Brazil nutshell is an excellent raw material to prepare efficient ACs which can be successfully used in the treatment of real hospital effluents.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719309562-ga1.jpg" width="422" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 12 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects〈/p〉 〈p〉Author(s): Li Li, Yunhui Yan, Jinge Du, Shuai Fu, Haiping Liu, Fengying Zhao, Jianguo Zhou〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Crystal defects play an important role on the physical and chemical properties of semiconductors. In this work, a series of Bi/Bi〈sub〉2〈/sub〉O〈sub〉2−x〈/sub〉CO〈sub〉3〈/sub〉 photocatalysts have been fabricated by an one-pot hydrothermal method, where glucose is used as reducing and morphological control agent. The phase structure, morphology, optical and photoelectrochemical properties of the photocatalysts are characterized by various techniques. These oxygen vacancies (OVs) have been confirmed and characterized by ESR spectroscopy and XPS spectra. The Bi/Bi〈sub〉2〈/sub〉O〈sub〉2−x〈/sub〉CO〈sub〉3〈/sub〉 photocatalysts exhibits highest removal efficiency of Lanasol Red 5B and ciprofloxacin. The corresponding degradation rate constant for Lanasol Red 5B is about 2.28 times higher than that of Bi〈sub〉2〈/sub〉O〈sub〉2〈/sub〉CO〈sub〉3〈/sub〉 under simulated solar irradiation, and 10.9 times under visible light irradiation, respectively. Radical scavenger experiments futher indicated that holes (h〈sup〉+〈/sup〉) and hydroxyl radical (•OH) are the main active species for Lanasol Red 5B degradation. This enhanced photocatalytic performance can be rationalized by the synergistic effects of Bi plasmon and OVs, resulting in, enhanced light-harvesting and electron- hole separation ability of Bi/Bi〈sub〉2〈/sub〉O〈sub〉2−x〈/sub〉CO〈sub〉3〈/sub〉 photocatalysts.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719309355-ga1.jpg" width="224" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 583〈/p〉 〈p〉Author(s): Andressa B. Nörnberg, Vinicios R. Gehrke, Henrique P. Mota, Edinalvo R. Camargo, André R. Fajardo〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Alginate (ALG) and alginate/cellulose (ALG/CEL) beads were prepared and tested as potential vehicles for encapsulation and controlled release of imazethapyr (IMZ), a broad spectrum herbicide. The incorporation of a small amount of CEL (5 w/w-%) into the ALG network allowed to increase the encapsulation efficiency of IMZ (〉85%). CEL also contributed to control of some important features such as the effect of pH on the liquid uptaking and stability in water. Release profile of IMZ from the prepared beads (ALG@IMZ and ALG/CEL@IMZ) was assessed in water, and it revealed that these carrier devices behaved as slow release formulations as compared to pure IMZ. Moreover, CEL-containing beads reduced the release of IMZ more efficiently than the pristine ALG beads. The release profiles of both carrier systems were well fitted by the Korsmeyer-Peppas model, which indicated that in both cases the IMZ release is driven by Fickian diffusion mechanism. The time taken for 50% of IMZ to be release was 11.30 days for ALG beads, while for the ALG/CEL beads this time was increased to 43.73 days. The experimental performance presented by ALG and ALG/CEL beads demonstrated that both systems could control and prolong the release of IMZ, which is paramount for their practical application as slow-release systems.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719309604-ga1.jpg" width="327" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 583〈/p〉 〈p〉Author(s): Minhaz Rahman, Xiaofei Zhao, Gordon F. Christopher〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The impact of interfacial properties on the processing of crude oil/water emulsions has led to increased studies examining films of asphaltene, the most surface active components of crude oil. However, crude has other surface active components. Although asphaltenes create a strong viscoelastic interfacial film at concentrations found in crude, the study of asphaltene films is limited in utility due to differences between their behavior and films composed from crude. However, crude oils are difficult to work with and characterize and are too complex to allow systematic studies. There is a need for more accurate but simple models of crude that could be used in various types of interfacial deformation. In this work, a simple two component model oil comprised asphaltenes, and resins dissolved in toluene’s are compared to both crude and single component interfaces undergoing interfacial shear. The two component model interface creates a response qualitatively like crude in both aggregation kinetics and strain sweep, whereas pure resin and asphaltene interfaces behave completely different. By adjusting the relative concentration of resin and asphaltene in the model oil, different types of oil are made that correspond to medium and heavy crudes.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092777571930768X-ga1.jpg" width="274" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 583〈/p〉 〈p〉Author(s): Shohei Yumiyama, Satoshi Kato, Yasuhiro Konishi, Toshiyuki Nomura〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The removal of adhered cells on surfaces is an important issue in every industrial process. Although bubbles are increasingly being considered for use in cleaning technology due to their positive properties, the cleaning effects of using bubbles and their mechanisms related to interaction forces remain poorly understood. Atomic force microscopy (AFM) is capable of nanoscale force resolution and has been increasingly applied to measure the interaction forces targeting bubbles or biological surfaces. However, few studies have reported on the quantitative measurement of interaction forces between a single microbial cell and a hydrophobic bubble surface. In this study, we attempted to conduct direct measurement of the interaction forces between a yeast cell and a microbubble (MB) using AFM. We demonstrated that the strong adhesive force is attributed to the capillary and hydrophobic forces between a yeast cell and a MB. This force was found to be larger than that between a yeast cell and a stainless-steel substrate. These findings provide useful information for various applications using MBs, including cleaning technology for industrial processes.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719309537-ga1.jpg" width="426" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 583〈/p〉 〈p〉Author(s): Duan Wang, Yuanbo Wu, Jinmeng Lv, Rongrong Wang, Sailong Xu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Sodium-ion batteries (SIBs) have been recognized as one type of the most potential technologies for low-cost rechargeable batteries owing to the abundant resource of sodium. Herein, we present nanosized maricite NaFePO〈sub〉4〈/sub〉 nanoparticles encapsulated within carbon (NFP@NPCM) via a sol-gel method. The resultant NFP@NPCM nanocomposite as cathode material for SIBs exhibits a high capacity retention of more than 80% after 50 cycles at 0.1C and good rate capacity. The good electrochemical performances are attributed to the NaFePO〈sub〉4〈/sub〉 nanoparticles and the conductive carbon coating, which facilitate the fast access of Na〈sup〉+〈/sup〉 ion and electron during the charging/discharging processes, respectively. Our result provides an alternative to prepare promising cathode material for SIBs toward practical application.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719309471-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 20 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 583〈/p〉 〈p〉Author(s): Wei Gan, Jian Zhang, Haihong Niu, Lei Bao, Hequn Hao, Yehan Yan, Keyue Wu, Xucheng Fu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The TiO〈sub〉2〈/sub〉 nanosheets with exposed (010) facets were synthesized via facile surfactant self-assembly. Then, the TiO〈sub〉2〈/sub〉 sheets were employed as scaffolding and deposited Ag/AgBr particles via improved oil/water self-assembly method. The TEM results suggested that Ag/AgBr particles well dispersed on the surface of TiO〈sub〉2〈/sub〉 sheets with diameter 1–4 nm. The modified of Ag/AgBr enhanced the absorption in the visible light region, which was due to surface plasmonic resonance (SPR) of the metallic Ag clusters formed on the surface of AgBr particle. The as-prepared hierarchical composites photocatalyst Ag/AgBr/TiO〈sub〉2〈/sub〉 exhibited excellent photocatalytic activity under nature solar-light irradiation and degraded ∼91.7% of Rhodamine (RhB) within 60 min. The degradation of colorless Bisphenol (BPA) further confirmed the photocatalytic abilities of Ag/AgBr/TiO〈sub〉2〈/sub〉. The quenching tests exhibited that the Ag/AgBr/TiO〈sub〉2〈/sub〉 composites photocatalytic degradation organic pollutions were mainly dominated by 〈sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉O〈sup〉2−〈/sup〉 oxidation reactions, while the h〈sup〉+〈/sup〉 and 〈sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉OH have a minor contribution. The improved photocatalytic activities can be attributed to the suitable size of Ag/AgBr particles, abundant surface active sites, effective photogenerated electron-hole pair's separation, which significantly improve the photocatalytic activity.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0927775719309586-ga1.jpg" width="264" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉