International Journal of Polymer Science The latest articles from Hindawi Publishing Corporation © 2016 , Hindawi Publishing Corporation . All rights reserved. Optimization of Process Parameters for ε-Polylysine Production by Response Surface Methods Tue, 28 Jun 2016 11:32:56 +0000 ε-Polylysine (ε-PL) is a highly safe natural food preservative with a broad antimicrobial spectrum, excellent corrosion resistances, and great commercial potentials. In the present work, we evaluated the ε-PL adsorption performances of HZB-3B and D155 resins and optimized the adsorption and desorption conditions by single-factor test, response surface method, and orthogonal design. The complexes of resin and ε-PL were characterized by SEM and FITR. The results indicated that D155 resin had the best ε-PL adsorption performance and was selected for the separation and purification of ε-PL. The conditions for the static adsorption of ε-PL on D155 resin were optimized as follows: ε-PL solution 40 g/L, pH 8.5, resins 15 g/L, and absorption time 14 h. The adsorption efficiency of ε-PL under the optimal conditions was 96.84%. The ε-PL adsorbed on the D155 resin was easily desorbed with 0.4 mol/L HCl at 30°C in 10 h. The highest desorption efficiency was 97.57% and the overall recovery of ε-PL was 94.49% under the optimal conditions. The excellent ε-PL adsorption and desorption properties of D155 resin including high selectivity and adsorption capacity, easy desorption, and high stability make it a good candidate for the isolation of ε-PL from fermentation broths. Maxiaoqi Zhu, Zhicai Zhang, Yiqiuyi Liu, Feng Wang, Lili Xia, Jianwei Xia, and Hongming Guo Copyright © 2016 Maxiaoqi Zhu et al. All rights reserved. Competitive Fixed-Bed Adsorption of Pb(II), Cu(II), and Ni(II) from Aqueous Solution Using Chitosan-Coated Bentonite Tue, 28 Jun 2016 07:36:18 +0000 Fixed-bed adsorption studies using chitosan-coated bentonite (CCB) as adsorbent media were investigated for the simultaneous adsorption of Pb(II), Cu(II), and Ni(II) from a multimetal system. The effects of operational parameters such as bed height, flow rate, and initial concentration on the length of mass transfer zone, breakthrough time, exhaustion time, and adsorption capacity at breakthrough were evaluated. With increasing bed height and decreasing flow rate and initial concentration, the breakthrough and exhaustion time were observed to favorably increase. Moreover, the adsorption capacity at breakthrough was observed to increase with decreasing initial concentration and flow rate and increasing bed height. The maximum adsorption capacity at breakthrough of 13.49 mg/g for Pb(II), 12.14 mg/g for Cu(II), and 10.29 mg/g for Ni(II) was attained at an initial influent concentration of 200 mg/L, bed height of 2.0 cm, and flow rate of 0.4 mL/min. Adsorption data were fitted with Adams-Bohart, Thomas, and Yoon-Nelson models. Experimental breakthrough curves were observed to be in good agreement ( and ) with the predicted curves generated by the kinetic models. This study demonstrates the effectiveness of CCB in the removal of Pb(II), Cu(II), and Ni(II) from a ternary metal solution. Wan-Chi Tsai, Mark Daniel G. de Luna, Hanna Lee P. Bermillo-Arriesgado, Cybelle M. Futalan, James I. Colades, and Meng-Wei Wan Copyright © 2016 Wan-Chi Tsai et al. All rights reserved. Long-Chain Alkylimidazolium Ionic Liquid Functionalization of Cellulose Nanofibers and Their Embedding in HDPE Matrix Tue, 28 Jun 2016 06:25:10 +0000 This paper presents a possible alternative to traditional cellulose nanofibers functionalization, by treatment of the material at low temperatures (25–35°C) with electron-beam irradiated 1-hexyl-3-methylimidazolium chloride ionic liquid. The treatment promotes decreasing the crystallinity of the cellulose with up to 45% and possible imidazolium moieties grafting to cellulose, as demonstrated from FTIR, XRD, and elemental analysis. The grafting determines water vapors uptake values with 50–70% lower and water vapors uptake rate with 50% lower than those of reference cellulose nanofibers. The grafting determined also improved adhesion of the cellulose nanofibers to HDPE, thus contributing to the obtaining of polymer matrix composites with improved properties. Catalin Croitoru and Silvia Patachia Copyright © 2016 Catalin Croitoru and Silvia Patachia. All rights reserved. Eggshell and Bacterial Cellulose Composite Membrane as Absorbent Material in Active Packaging Thu, 23 Jun 2016 11:13:56 +0000 Bacterial cellulose and eggshell composite was successfully developed. Eggshell was mixed with bacterial cellulose suspension and it was casted as a composite film. CaCO3 derived from eggshell was compared with its commercial availability. It can be noted that good dispersion of eggshell particle was prepared. Eggshell particle was irregular in shape with a variation in size. It existed in bacterial cellulose network. Characterization on composite was focused on thermal and mechanical properties. It showed that flexibility and thermal stability of composite were enhanced. No significant effect of mechanical properties was therefore observed. The thermal stability of composite was stable up to 300°C. The adsorption experiment on water and vegetable oil capacity was performed. The enhancement on adsorption was due to the existence of eggshell in bacterial cellulose composite. It exhibited the potential to be a good candidate for absorbent material in active packaging. S. Ummartyotin, P. Pisitsak, and C. Pechyen Copyright © 2016 S. Ummartyotin et al. All rights reserved. Synthesis, Properties, and In Vitro Hydrolytic Degradation of Poly(d,l-lactide-co-glycolide-co-ε-caprolactone) Mon, 20 Jun 2016 07:30:26 +0000 Random copolymers of poly(d,l-lactide-co-glycolide-co-ε-caprolactone) (PLGC) were synthesized by the ring-opening polymerization of d,l-lactide (DLLA), glycolide (GA), and ε-caprolactone (CL). The effects of CL on the copolymers were evaluated to prepare suitable copolymers with controlled properties. Our results showed that the CL content significantly influenced the thermal and mechanical properties of the copolymers and that the CL content in compositions could be altered to control properties of random copolymers. The in vitro hydrolytic degradation of the resulting implants showed that the degradation rate of PLGC was lower than that of PLGA, which could markedly reduce acidic degradation products. Finally, we demonstrated that higher CL contents in compositions slowed degradation rates. Yixiu Liu, Xizhuang Bai, and A. Liang Copyright © 2016 Yixiu Liu et al. All rights reserved. Effect of Different Nucleating Agents on the Crystallization of Ziegler-Natta Isotactic Polypropylene Thu, 16 Jun 2016 14:29:38 +0000 Ziegler-Natta isotactic polypropylene (iPP) was melt mixed with four different nucleating agents (carbon nanotubes (CNT), carbon nanofibers (CNF), lithium benzoate (LiBe), and a sorbitol derivative (Millad)) in order to study their effect on the crystallization of iPP. It was found that the four different nucleating agents promote the alpha crystalline form. At 0.01 wt%, the carbon nanoparticles produced the higher crystallization temperature “” (~119°C), whereas, at 0.10 wt%, LiBe and Millad produced a markedly higher (~125°C). of pure iPP was 111°C. With 0.1 wt% nucleating agent, at 120°C, the crystallization half-life time of PP, when using LiBe or Millad, was 15 times faster than for pure PP, whereas, when using carbon nanoparticles, it was 20–25 times faster. At 135°C, with 0.01 wt% nucleating agent, the isothermal crystallization process of iPP was completed after 25 min, as well as with Millad. With LiBe, it was completed after just 15 min and, with any of the carbon nanoparticles, it was practically over after only a couple of minutes. Felipe Avalos-Belmontes, Luis Francisco Ramos-deValle, Adriana Berenice Espinoza-Martínez, Juan Guillermo Martínez-Colunga, Eduardo Ramírez-Vargas, Saul Sánchez-Valdés, Jose Carlos Ortíz-Cisneros, Esperanza Elizabeth Martínez-Segovia, and Flora Itzel Beltrán-Ramírez Copyright © 2016 Felipe Avalos-Belmontes et al. All rights reserved. Bottom-Up Fabrication of PEG Brush on Poly(dimethylsiloxane) for Antifouling Surface Construction Wed, 15 Jun 2016 11:23:02 +0000 Poly(dimethylsiloxane) silicones have found many applications in biomedical devices, whereas their surface hydrophobicity always brings about unexpected bioadhesion, causing complications of the implanted biomedical devices. In this work, surface-initiated reversible addition-fragmentation chain transfer (SI-RAFT) polymerization was utilized to generate PEG brushes on silicone surface, obtaining highly hydrophilic surface coatings. Such PEG brush coated silicone presents excellent antifouling to protein, cells, and bacteria, which may have great potential in implantable biomaterial surface modifications. Junmei Tang, Yuemei Han, Hao Chen, and Quankui Lin Copyright © 2016 Junmei Tang et al. All rights reserved. Preparation and Application of Cationic Modified Cellulose Fibrils as a Papermaking Additive Wed, 15 Jun 2016 09:14:48 +0000 This paper deals with cationic modified cellulose fibrils obtained by reacting the cellulose fibrils with 2,3-epoxypropyltrimethylammonium chloride (EPTMAC). The physical and chemical properties of unmodified cellulose fibrils (UMCF) and cationic modified cellulose fibrils (CMCF) were characterized by SEM, FTIR, degree of substitution, colloid titration, zeta potential, and thermogravimetric analysis. The experimental results showed that, after cationization, surface charge density and zeta potential reversed, thermal stability decreased, and new functional groups appeared, while the surface morphology did not show much difference from the UMCF. With the addition of three kinds of additives (UMCF, CMCF, and cationic starch (CS)) to BCTMP, the addition of UMCF and CMCF had little effect on zeta potential, while the addition of CS changed zeta potential obviously. With the increasing of additive amount, the bulk of paper sheets added CMCF did not change obviously, while the bulk of paper sheets added UMCF and CS decreased rapidly. With regard to physical strength, all the three kinds of additives could improve the tensile index and tear index; the tensile index of paper sheets added CS was higher than that of added UMCF and CMCF, while the tear index of paper sheets added CMCF was the highest among the three additives. Yanhong Gao, Qun Li, Yu Shi, and Ruitao Cha Copyright © 2016 Yanhong Gao et al. All rights reserved. Synthesis of Highly Sulfonated Poly(arylene ether) Containing Multiphenyl for Proton Exchange Membrane Materials Tue, 14 Jun 2016 09:27:24 +0000 A series of sterically hindered, sulfonated, poly(arylene ether) polymers were synthesized by nucleophilic polycondensation reaction using 4,4′′′′-difluoro-3,3′′′′-bistrifluoromethyl-2′′,3′′,5′′,6′′-tetraphenyl-[1,1′;4′,1′′;4′′,1′′′;4′′′,1′′′′]-pentaphenyl and 4,4′-biphenol and were prepared through postpolymerization sulfonation. The chemical structures were confirmed by 1H NMR. Subsequent to sulfonation, solvent-casting membranes were provided ion exchange capacity (IEC) values ranging from 0.39 to 2.90 mmol/g. Proton conductivities of membranes ranged from 143 to 228 mS/cm at 80°C under fully humidified conditions which were higher than that of Nafion 117. The membrane also exhibited considerably dimension stability, oxidative stability, and hydrolytic stability. The microphase structure was investigated by transmission electron microscopy (TEM) and the ionic aggregation of sulfonic acid groups exhibited spherical ionic clusters with well-developed phase separated morphology. The results indicated that the membranes are promising candidates for application as proton exchange membranes. This investigation demonstrates introducing multiphenylated moieties to create a high free volume polymer that provides dimensionally stable and high proton conductivity membranes. Yi-Chiang Huang, Ruei-Hong Tai, Hsu-Feng Lee, Po-Hsun Wang, Ram Gopal, Chun-Che Lee, Mei-Ying Chang, and Wen-Yao Huang Copyright © 2016 Yi-Chiang Huang et al. All rights reserved. Optimization and Prediction of Mechanical and Thermal Properties of Graphene/LLDPE Nanocomposites by Using Artificial Neural Networks Mon, 13 Jun 2016 09:29:51 +0000 The focus of this work is to develop the knowledge of prediction of the physical and chemical properties of processed linear low density polyethylene (LLDPE)/graphene nanoplatelets composites. Composites made from LLDPE reinforced with 1, 2, 4, 6, 8, and 10 wt% grade C graphene nanoplatelets (C-GNP) were processed in a twin screw extruder with three different screw speeds and feeder speeds (50, 100, and 150 rpm). These applied conditions are used to optimize the following properties: thermal conductivity, crystallization temperature, degradation temperature, and tensile strength while prediction of these properties was done through artificial neural network (ANN). The three first properties increased with increase in both screw speed and C-GNP content. The tensile strength reached a maximum value at 4 wt% C-GNP and a speed of 150 rpm as this represented the optimum condition for the stress transfer through the amorphous chains of the matrix to the C-GNP. ANN can be confidently used as a tool to predict the above material properties before investing in development programs and actual manufacturing, thus significantly saving money, time, and effort. P. Noorunnisa Khanam, MA AlMaadeed, Sumaaya AlMaadeed, Suchithra Kunhoth, M. Ouederni, D. Sun, A. Hamilton, Eileen Harkin Jones, and Beatriz Mayoral Copyright © 2016 P. Noorunnisa Khanam et al. All rights reserved. Protein Adsorption on Hybrids of Thermoresponsive Polymers and Single-Walled Carbon Nanotubes Thu, 09 Jun 2016 10:27:20 +0000 Poly(N-isopropylacrylamide) (PNIPAAm) is one of the most popular thermoresponsive polymers. Adsorption of RecA proteins onto hybrids of PNIPAAm and single-walled carbon nanotubes (SWNTs) was observed in the presence and absence of DNA molecules. Although RecA molecules were adsorbed efficiently onto the hybrid surfaces at 37°C, even in the absence of DNA molecules, the adsorption of RecA was inhibited at 4°C. These results suggest that the thermoresponsive functions of PNIPAAm were effective, even on the SWNT surfaces, which supports the possibility of developing nanobiodevices using PNIPAAm-SWNT hybrids. However, although RecA is a DNA binding protein, there was no significant difference in the adsorption of RecA onto PNIPAAm-SWNT surfaces with and without DNA molecules. This study provides fundamental information for potential biological applications of PNIPAAm-SWNT hybrids. Kazuo Umemura, Katsuki Izumi, Yoshikazu Kumashiro, Shusuke Oura, and Teruo Okano Copyright © 2016 Kazuo Umemura et al. All rights reserved. Effect of Microwave Radiation on the Synthesis of Poly(3-hexylthiophene) and the Subsequent Photovoltaic Performance of CdS/P3HT Solar Cells Sun, 05 Jun 2016 11:15:17 +0000 Poly(3-hexylthiophene) (P3HT) is a semiconductor polymer that has been proved to be a good electron donor in organic or hybrid solar cells. In this work, a detailed study of P3HT synthesis in CH2Cl2 solvent by oxidative method with and without MW assistance has been conducted. Effects of synthesis process parameters on the physical properties of P3HT products and their application in hybrid CdS/P3HT photovoltaic devices were studied. It is observed that the use of MW as well as the reaction time affected the reaction yield and properties of the polymer products. It was found that, by the traditional method (without MW), the maximum yield and the properties of the polymer products were similar after 2 h or 24 h of synthesis. The optimal reaction time with MW for P3HT polymerization in CH2Cl2 solvent was 1 h, and the obtained P3HT product showed similar or better properties than those P3HT polymers synthesized by the traditional method in the same solvent. The effect of using MW during the synthesis was to increase yield and crystal size of P3HT. Larger energy conversion efficiency of ITO/CdS/P3HT/CP-Au devices was obtained when the P3HT product had higher molecular weight and head/tail-head/tail (HT-HT) triad contents. C. H. García-Escobar, M. E. Nicho, Hailin Hu, G. Alvarado-Tenorio, P. Altuzar-Coello, G. Cadenas-Pliego, and D. Hernández-Martínez Copyright © 2016 C. H. García-Escobar et al. All rights reserved. Composites and Nanocomposites Based on Renewable and Sustainable Materials Thu, 02 Jun 2016 08:31:50 +0000 Matheus Poletto, Heitor Luiz Ornaghi Júnior, P. M. Visakh, and Yoshihiko Arao Copyright © 2016 Matheus Poletto et al. All rights reserved. Water Properties of Soft Contact Lenses: A Comparative Near-Infrared Study of Two Hydrogel Materials Wed, 01 Jun 2016 13:21:32 +0000 The functionality of soft contact lenses depends strongly on the water content and their water-transport ability. This study was conducted in order to examine the state of water in two sets of soft contact lenses: VSO38, pHEMA Filcon I 1, and VSO50, copolymer of HEMA and VP Filcon II 1 (HEMA = 2-hydroxy-ethyl methacrylate; VP = vinyl pyrrolidone). Hydrogel lenses were studied using near-infrared spectroscopy and the novel Aquaphotomics approach in order to determine the state of water in materials based on their near-infrared spectra. Aquaphotomics approach investigates absorption at specific vibrational bands of water’s covalent and hydrogen bonds which can provide information on how the water structure changes with the structural change of the polymer network. Principal component analysis and specific star-chart “aquagram” were used to analyse water spectral pattern in hydrogel materials. The findings show that material VSO38 has water predominantly organized in bound state, while material with higher water content, VSO50, has more free and weakly hydrogen bonded water. Our findings define in detail exact water species existing and interacting with the polymer network. The results show qualitative and quantitative possibilities of Aquaphotomics for better modelling and understanding water behaviour in hydrogel materials. Jelena Munćan, Ivana Mileusnić, Jovana Šakota Rosić, Aleksandra Vasić-Milovanović, and Lidija Matija Copyright © 2016 Jelena Munćan et al. All rights reserved. Combinational Effect of Cell Adhesion Biomolecules and Their Immobilized Polymer Property to Enhance Cell-Selective Adhesion Tue, 31 May 2016 09:42:14 +0000 Although surface immobilization of medical devices with bioactive molecules is one of the most widely used strategies to improve biocompatibility, the physicochemical properties of the biomaterials significantly impact the activity of the immobilized molecules. Herein we investigate the combinational effects of cell-selective biomolecules and the hydrophobicity/hydrophilicity of the polymeric substrate on selective adhesion of endothelial cells (ECs), fibroblasts (FBs), and smooth muscle cells (SMCs). To control the polymeric substrate, biomolecules are immobilized on thermoresponsive poly(N-isopropylacrylamide-co-2-carboxyisopropylacrylamide) (poly(NIPAAm-co-CIPAAm))-grafted glass surfaces. By switching the molecular conformation of the biomolecule-immobilized polymers, the cell-selective adhesion performances are evaluated. In case of RGDS (Arg-Gly-Asp-Ser) peptide-immobilized surfaces, all cell types adhere well regardless of the surface hydrophobicity. On the other hand, a tri-Arg-immobilized surface exhibits FB-selectivity when the surface is hydrophilic. Additionally, a tri-Ile-immobilized surface exhibits EC-selective cell adhesion when the surface is hydrophobic. We believe that the proposed concept, which is used to investigate the biomolecule-immobilized surface combination, is important to produce new biomaterials, which are highly demanded for medical implants and tissue engineering. Rio Kurimoto, Kei Kanie, Naokazu Idota, Mitsuo Hara, Shusaku Nagano, Takehiko Tsukahara, Yuji Narita, Hiroyuki Honda, Masanobu Naito, Mitsuhiro Ebara, and Ryuji Kato Copyright © 2016 Rio Kurimoto et al. All rights reserved. Effect of Acetate Group Content in Ethylene-Vinyl Acetate Copolymer on Properties of Composite Based on Low Density Polyethylene and Polyamide-6 Thu, 26 May 2016 12:56:50 +0000 The effect of the content of vinyl acetate groups in ethylene-vinyl acetate copolymer on the properties of polymer composite based on low density polyethylene and polyamide-6 was studied. Ethylene-vinyl acetate copolymer containing less vinyl acetate groups (10–14 wt.%) has a positive compatibility effect on polymer composite than ethylene-vinyl acetate copolymer containing 21–30 wt.% vinyl acetate groups. The polymer composites of LDPE, PA-6, and EVA containing 10–14 wt.% vinyl acetate groups possess the ability of biodegradation. The physical-mechanical properties of sample and molecular mass reduce after 28 days of incubation. Nhi Dinh Bui, Ngo Dinh Vu, Thao Thi Minh, Huong Thi Thanh Dam, Regina Romanovna Spiridonova, and Semenovich Alexandr Sirotkin Copyright © 2016 Nhi Dinh Bui et al. All rights reserved. Magnetically Triggered Monodispersed Nanocomposite Fabricated by Microfluidic Approach for Drug Delivery Thu, 26 May 2016 08:58:22 +0000 Responsive microgel poly(N-isopropylacrylamide) or PNIPAM is a gel that can swell or shrink in response to external stimuli (temperature, pH, etc.). In this work, a nanocomposite gel is developed consisting of PNIPAM and magnetic iron oxide nanobeads for controlled release of liquids (like drugs) upon exposure to an alternating magnetic field. Microparticles of the nanocomposite are fabricated efficiently with a monodisperse size distribution and a diameter ranging from 20 to 500 µm at a rate of up to 1 kHz using a simple and inexpensive microfluidic system. The nanocomposite is heated through magnetic losses, which is exploited for a remotely stimulated liquid release. The efficiency of the microparticles for controlled drug release applications is tested with a solution of Rhodamine B as a liquid drug model. In continuous and pulsatile mode, a release of 7% and 80% was achieved, respectively. Compared to external thermal actuation that heats the entire surrounding or embedded heaters that need complex fabrication steps, the magnetic actuation provides localized heating and is easy to implement with our microfluidic fabrication method. O. Yassine, E. Q. Li, A. Alfadhel, A. Zaher, M. Kavaldzhiev, S. T. Thoroddsen, and J. Kosel Copyright © 2016 O. Yassine et al. All rights reserved. Adsorption of Polyvinylpyrrolidone over the Silica Surface: As Affected by Pretreatment of Adsorbent and Molar Mass of Polymer Adsorbate Tue, 24 May 2016 14:22:35 +0000 The adsorption of polyvinylpyrrolidone over the surface of silica has been investigated. The impact of molar mass of the polymer, pH, and pretreatment temperature of silica particles have been evaluated by means of FTIR spectroscopy and electrophoretic measurements. The silica particles used have narrow particle size distribution. The zeta potential of the aqueous silica suspension was decreased with the increase in pH. The amount of polymer adsorbed was increased with the increase in pretreatment temperature, time, concentration, pH, zeta potential, and molar mass of the polymer. The addition of polymer to the system increased the zeta potential due to adsorption of polymer on the surface of the particles. However, the impact increased with the increase in molecular mass of the polymer. The IR spectra obtained before and after adsorption of polymer concluded that, mostly, hydrogen bonding is responsible for the adsorption phenomena; however, hydrophobic interactions also play a significant role. The mechanism has been investigated and established through FTIR spectroscopy. Laila M. Al-Harbi, Samia A. Kosa, Musa K. Baloch, Qaisar A. Bhatti, and El-Sayed El-Badawey H. El-Mossalamy Copyright © 2016 Laila M. Al-Harbi et al. All rights reserved. Preparation and Characterization of a Bioartificial Polymeric Material: Bilayer of Cellulose Acetate-PVA Tue, 24 May 2016 14:12:52 +0000 A new bioartificial polymeric material consisting of a bilayer of cellulose acetate and poly(vinyl alcohol) was successfully obtained by casting method. The material was characterized by Fourier transform infrared spectroscopy, contact angle, scanning electron microscopy, differential scanning calorimetry, gas permeability, water vapor permeability, and mechanical properties. The characterization indicates that two distinct and well-differentiated surfaces were achieved without detriment to the bulk properties. The interaction between natural and synthetic polymers indeed enhanced the gas permeability as well as the water vapor permeability in comparison to the original components, although mechanical properties were not substantially boosted by the combination of both. Moreover, beyond the interface, there were no detected interactions between the polymers as can be evidenced by the presence of a unique in the bilayer. The amalgamation of the relatively good mechanical properties with the two differentiated surfaces and the improvement of the permeability properties could indicate the potential of the material for being used in medicine. Andrés Bernal-Ballén, Ivo Kuritka, and Petr Saha Copyright © 2016 Andrés Bernal-Ballén et al. All rights reserved. Extraction and Hydrophobic Modification of Cotton Stalk Bark Fiber Tue, 24 May 2016 09:41:27 +0000 Cotton stalk bark fiber (CSBF) was extracted at high temperature and under high pressure, under the condition of the alkali content of 11 wt%. Experimental results proved that the extraction yield of CSBF was 27.3 wt%, and the residual alkali concentration was 2.1 wt%. Then five kinds of modifiers including methyl methacrylate (MMA), MMA plus initiator, epoxy propane, copper ethanolamine, and silane coupling agent were chosen to modify the surface of CSBF. It was found by measuring water retention value (WRV) that these five kinds of modifiers were all effective and the silane coupling agent was best modifier among all. The optimal modifying conditions of silane coupling agent were obtained: modifier concentration was 5%, the mixing temperature was 20°C, the mixing time was 1 h, and vacuum drying time was 1 h. Under the optimal condition, the WRV of the modified CSBF was 89%. It is expected that these modified CSBF may be a filler with strengthening effect in wood plastic composites (WPC) fields. Ya-Yu Li, Guang-Ming Du, Xin-Jie Feng, Ya-Wei Mu, and De-Qiang Li Copyright © 2016 Ya-Yu Li et al. All rights reserved. Synthesis and Characterization of Uniform Spherical Nanoporous TiO2 Aerogel Templated by Cellulose Alcohol-Gel with Enhanced Photocatalytic Activity Tue, 24 May 2016 06:41:46 +0000 The spherical nanoporous TiO2 aerogels were prepared by a simple ethanol-thermal method, using spherical cellulose alcohol-gel as the template. The morphology, crystalline structure, pore size, specific surface area, and the photocatalytic activity of obtained TiO2 aerogel were separately characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N2 adsorption-desorption isotherms, and double beam UV-VIS spectrophotometer. The characteristics of TiO2 aerogels presented uniform sphere shape, good internal structural morphology, high specific surface area (ranging from 111.88 to 149.95 m2/g), and good crystalline anatase phase. Moreover, methyl orange dye was used as the target pollutant to characterize the photocatalytic activities and the adsorption performance. The photocatalytic experiment shows that the obtained spherical TiO2 aerogels had a higher degradation ratio of 92.9% on methyl orange dye compared with aspherical TiO2 aerogels prepared from other concentrations of tetrabutyl orthotitanate (TBOT). Zhiming Liu, Peng Wu, Shaoli Yang, Haiying Wang, and Chunde Jin Copyright © 2016 Zhiming Liu et al. All rights reserved. A Study on Physical Performance for Poly(L-lactic acid) in Addition to Layered Strontium Phenylphosphonate Sun, 22 May 2016 08:16:06 +0000 The organic-inorganic hybrid layered strontium phenylphosphonate (SrP) was synthesized by using strontium chloride and phenylphosphinic acid. And the influence of layered SrP on the crystallization behavior and thermal stability of poly(L-lactic acid) (PLLA) was investigated through DSC, XRD, and TGA. Both DSC and XRD results demonstrated that layered SrP had the powerful accelerated ability for PLLA crystallization, and in the range of studied concentration, 0.7 wt%–1 wt% is the optimum concentration range to achieve rapid crystallization of PLLA. Meantime, as a result, the increase of cooling rate in nonisothermal crystallization procedure seriously affected the crystallization accelerated efficiency of SrP. Thermal stability measurement showed that layered SrP could cause the onset decomposition temperature of PLLA to decrease, but the thermal decomposition behavior of PLLA hardly depended on the SrP concentration. Yan-Hua Zhang and Yan-Hua Cai Copyright © 2016 Yan-Hua Zhang and Yan-Hua Cai. All rights reserved. Influence of Cellulose on the Mechanical and Thermal Stability of ABS Plastic Composites Thu, 19 May 2016 12:06:27 +0000 Microcrystalline cellulose was explored as possible biodegradable fillers in the fabrication of ABS plastic composites. TGA indicates that upon inclusion of cellulose microcrystals the thermal stability of the ABS plastics was improved significantly when compared to the neat ABS plastic counterparts. Furthermore, inclusion of extracted cellulose from plant biomass showed a higher thermal stability with maximum decomposition temperatures around 131.95°C and 124.19°C for cellulose from cotton and Hibiscus sabdariffa, respectively, when compared to that of the purchased cellulose. In addition, TMA revealed that the average CTE value for the neat ABS and 1 : 1 ratio of cellulose to ABS fabricated in this study was significantly lower than the reported CTE (ca. 73.8 μm/m°C). K. Crews, C. Huntley, D. Cooley, B. Phillips, and M. Curry Copyright © 2016 K. Crews et al. All rights reserved. Self-Shrinkage Behaviors of Waste Paper Fiber Reinforced Cement Paste considering Its Self-Curing Effect at Early-Ages Thu, 19 May 2016 06:29:38 +0000 The aim of this paper was to study how the early-age self-shrinkage behavior of cement paste is affected by the addition of the waste paper fibers under sealed conditions. Although the primary focus was to determine whether the waste paper fibers are suitable to mitigate self-shrinkage as an internal curing agent under different adding ways, evaluating their strength, pore structure, and hydration properties provided further insight into the self-cured behavior of cement paste. Under the wet mixing condition, the waste paper fibers could mitigate the self-shrinkage of cement paste and, at additions of 0.2% by mass of cement, the waste paper fibers were found to show significant self-shrinkage cracking control while providing some internal curing. In addition, the self-curing efficiency results were analyzed based on the strength and the self-shrinkage behaviors of cement paste. Results indicated that, under a low water cement ratio, an optimal dosage and adding ways of the waste paper fibers could enhance the self-curing efficiency of cement paste. Zhengwu Jiang, Xiuyan Guo, Wenting Li, and Qing Chen Copyright © 2016 Zhengwu Jiang et al. All rights reserved. Effect of Reinforcement of Hydrophobic Grade Banana (Musa ornata) Bark Fiber on the Physicomechanical Properties of Isotactic Polypropylene Tue, 17 May 2016 08:17:17 +0000 This research studied the physicomechanical as well as morphological properties of alkali treated (NaOH and KMnO4) and untreated banana bark fiber (BBF) reinforced polypropylene composites. A detailed structural and morphological characterization was performed using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and mechanical properties testing (tensile strength, flexural strength, and microhardness). Chemical treatments improved the hydrophobic property of the fiber and it is found to be better for KMnO4 treatment. Composites with 0, 5, 10, and 15 wt.% loadings were then compared for water uptake studies and revealed that KMnO4 treated fiber composites absorb less water compared to others. KMnO4 treatment with 15% fiber loading improved the tensile strength, flexural strength, and microhardness of the composites compared to raw and NaOH treated fiber loadings. TGA analysis also shows onset temperature at 400~500°C that is associated with the decomposition of the banana fibers constituents including lignin, cellulose, and hemicelluloses which suggests better thermomechanical stability. All of the values suggest that 15% KMnO4 treated banana bark fiber (BBF)/PP composites were found to be better than those of the raw and NaOH treated ones. Md. Mamunur Rashid, Sabrin A. Samad, M. A. Gafur, Md. Rakibul Qadir, and A. M. Sarwaruddin Chowdhury Copyright © 2016 Md. Mamunur Rashid et al. All rights reserved. Influence of Sodium Alginate on Hypoglycemic Activity of Metformin Hydrochloride in the Microspheres Obtained by the Spray Drying Tue, 17 May 2016 07:44:59 +0000 Alginate microspheres with metformin hydrochloride were prepared by the spray drying method in order to improve residence time of drug in the stomach. Nine formulations (F1–F9) with various drug : polymer ratio (1 : 2, 1 : 1, and 2 : 1) and different sodium alginate concentration (1%, 2%, and 3%) were evaluated for size, morphology, drug loading, Zeta potential, and swelling degree. In vitro drug release, mathematical release profile, and physical state of microspheres were also evaluated. Optimal formulation characterized by the highest drug loading was formulation F6 (drug : polymer ratio 2 : 1 and 2% alginate solution). Based on glucose uptake in Saccharomyces cerevisiae cells and α-amylase inhibition tests, it could be concluded that alginate microspheres enhance hypoglycemic activity of metformin hydrochloride evaluated in vitro. Designed microspheres are promising as alternative, multicompartment dosage form for metformin hydrochloride delivery. Marta Szekalska, Magdalena Wróblewska, Katarzyna Sosnowska, and Katarzyna Winnicka Copyright © 2016 Marta Szekalska et al. All rights reserved. Effect of Grinding Methods on Structural, Physicochemical, and Functional Properties of Insoluble Dietary Fiber from Orange Peel Mon, 16 May 2016 06:34:58 +0000 This study evaluated the effect of grinding methods (regular laboratory milling, ultra centrifugal rotor milling, and ball milling) on structural, physicochemical, and functional properties of insoluble dietary fiber (IDF) fraction from orange peel. The results demonstrated that both ultra centrifugal milling and ball milling could effectively decrease average particle size of IDF fraction (81.40 μm and 19.63 μm, resp.). The matrix structure of IDF fraction was destroyed but FTIR structure had no major change after grinding. As particle size decreased, the bulk density and lightness of IDF fraction increased and a redistribution of fiber components from insoluble to soluble fractions was observed. Furthermore, ball milled IDF fraction exhibited significantly higher capacity to retard glucose diffusion and inhibit α-amylase activity (35.09%). This work would give useful insight into effect of grinding methods on properties and functions of orange peel IDF in food industry. Yanlong Liu, Lufeng Wang, Fengxia Liu, and Siyi Pan Copyright © 2016 Yanlong Liu et al. All rights reserved. The Transmittance, Transmittance Wavefront, and Laser Induced Damage Properties of Thin Fluoride Polymer Films May Be Used as Short Pulse Laser Debris Shields Thu, 12 May 2016 13:09:13 +0000 Debris mitigation which pollutes and even damages the optical elements is a major challenge for all high-peak-power lasers system. In order to solve the problem, we employed some preliminary research. In this work, first, the film optical properties of fluorinated ethylene propylene (FEP), perfluoroalkoxy copolymer (PFA), and ethane-tetrafluoroethylene copolymer (ETFE) were investigated with respect to their possible application as laser debris shields. The results indicate that three of the polymer films have high transmittance at 355 nm, especially in FEP film, the transmittance of which at 355 nm is near to 94%. The transmittance wavefront and the laser that induce damage of FEP film were investigated further. The result indicates that the wavefront error of FEP film (with a diameter of 90 mm) is about 0.33λ. The damage test was performed by a 355 nm neodymium:yttrium aluminum garnet (Nd:YAG) laser with a 9.3 ns pulse duration, and it was found that the highest nondamage fluence for FEP film is 10.35 J/cm2. Through a demonstration experiment, it was testified that the FEP film can prevent large amount of metal fractions and the FEP film can be used as the debris shields indeed. Shufan Chen, Chuanqun Huang, Xiaodong Jiang, Xuan Luo, Yu Fang, and Weidong Wu Copyright © 2016 Shufan Chen et al. All rights reserved. Preparation of Two-Layer Anion-Exchange Poly(ethersulfone) Based Membrane: Effect of Surface Modification Sun, 08 May 2016 11:53:29 +0000 The present work deals with the surface modification of a commercial microfiltration poly(ethersulfone) membrane by graft polymerization technique. Poly(styrene-co-divinylbenzene-co-4-vinylbenzylchloride) surface layer was covalently attached onto the poly(ethersulfone) support layer to improve the membrane electrochemical properties. Followed by amination, a two-layer anion-exchange membrane was prepared. The effect of surface layer treatment using the extraction in various solvents on membrane morphological and electrochemical characteristics was studied. The membranes were tested from the point of view of water content, ion-exchange capacity, specific resistance, permselectivity, FT-IR spectroscopy, and SEM analysis. It was found that the two-layer anion-exchange membranes after the extraction using tetrahydrofuran or toluene exhibited smooth and porous surface layer, which resulted in improved ion-exchange capacity, electrical resistance, and permselectivity of the membranes. Lucie Zarybnicka, Eliska Stranska, Jana Machotova, and Gabriela Lencova Copyright © 2016 Lucie Zarybnicka et al. All rights reserved. Incorporation of Amphipathic Diblock Copolymer in Lipid Bilayer for Improving pH Responsiveness Wed, 04 May 2016 14:26:19 +0000 Diblock copolymers (mPEG-b-PDPA), which were designed to possess pH-sensitivity as well as amphipathy, were used as an intelligent lock in the liposomal membrane. The so-called pH-sensitive liposomes were prepared by simple mixing of the synthesized mPEG-b-PDPA with phospholipids and cholesterol. Fluorescence polarization at pH 7.4 showed that the membrane stability of the hybrid liposome was significantly increased compared with the pure liposome. Therefore, in the neutral environment, the leakage of doxorubicin (DOX) was inhibited. However, when pH decreased to 6.0, DOX release rate increased by 60% due to the escape of copolymer. The effects of the membrane composition and the PDPA segment length on bilayer membrane functions were investigated. These results revealed that the synthesized copolymers increased the difference in DOX cumulative release between pH 7.4 and 6.0, that is, improved the pH-controllability of the drug release from hybrid liposomes. Tian Xia, Weiju Hao, Yazhuo Shang, Shouhong Xu, and Honglai Liu Copyright © 2016 Tian Xia et al. All rights reserved.