International Journal of Polymer Science The latest articles from Hindawi Publishing Corporation © 2016 , Hindawi Publishing Corporation . All rights reserved. Adsorption of Polyvinylpyrrolidone over the Silica Surface: As Affected by Pretreatment of Adsorbate and Molar Mass of Polymer Adsorbent 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. Biodegradable Polymers for Medical Applications Thu, 28 Apr 2016 14:08:44 +0000 Anezka Lengalova, Alenka Vesel, Yakai Feng, and Vitor Sencadas Copyright © 2016 Anezka Lengalova et al. All rights reserved. Electrospun PEDOT:PSS/PVP Nanofibers for CO Gas Sensing with Quartz Crystal Microbalance Technique Wed, 27 Apr 2016 13:53:39 +0000 Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/polyvinylpyrrolidone (PEDOT:PSS/PVP) composite nanofibers were successfully fabricated via electrospinning and used as a quartz crystal microbalance (QCM) sensor for detecting CO gas. The electrical property of individual PEDOT:PSS/PVP nanofibers was characterized and the room temperature resistivity was at the magnitude of 105 Ω·m. The QCM sensor based on PEDOT:PSS/PVP nanofibers was sensitive to low concentration (5–50 ppm) CO. In the range of 5–50 ppm CO, the relationship between the response of PEDOT:PSS nanofibers and the CO concentration was linear. Nevertheless, when the concentration exceeded 50 ppm, the adsorption of the nanofiber membrane for CO gas reached saturation and the resonant frequency range had no change. Therefore, the results open an approach to create electrospun PEDOT:PSS/PVP for gas sensing applications. Hong-Di Zhang, Xu Yan, Zhi-Hua Zhang, Gu-Feng Yu, Wen-Peng Han, Jun-Cheng Zhang, and Yun-Ze Long Copyright © 2016 Hong-Di Zhang et al. All rights reserved. Impact of Block Length and Temperature over Self-Assembling Behavior of Block Copolymers Sun, 24 Apr 2016 11:49:04 +0000 Self-assembling behavior of block copolymers having water-soluble portion as one of the blocks plays key role in the properties and applications of the copolymers. Therefore, we have synthesized block copolymers of different block length and investigated their self-assembling behavior with reference to concentration and temperature using surface tension and conductance measurement techniques. The results obtained through both techniques concluded that critical micelles concentration (CMC) was decreased from 0.100 to 0.078 g/dL with the increase in length of water insoluble block and 0.100 to 0.068 g/dL for the increased temperature. was also decreased with the increase in temperature of the system, concluding that the micellization process was encouraged with the increase in temperature and block length. However, values were highest for short block length copolymer. The surface excess concentration obtained from surface tension data concluded that it was highest for short block length and vice versa and was increased with the increase in temperature of the system. However, the minimum area per molecule was largest for highest molecular weight copolymers or having longest water insoluble block and decreases with the increase in temperature. Samia A. Kosa, Laila M. Al-Harbi, Musa Kaleem Baloch, Irfan Ullah, and Elsayed H. El-Mossalamy Copyright © 2016 Samia A. Kosa et al. All rights reserved. Schizophyllum commune Lipase Production on Pretreated Sugarcane Bagasse and Its Effectiveness Wed, 20 Apr 2016 10:29:59 +0000 Schizophyllum commune UTARA1 was used for lipase production under solid state fermentation (SSF) of sugarcane bagasse (SB) impregnated with used cooking oil medium. Pretreatments of steam, microwave, hydrochloric acid (HCl), sodium hydroxide (NaOH), and their combinations, such as steam-assisted HCl, steam-assisted NaOH, microwave-assisted HCl, and microwave-assisted NaOH, on the milled SB, were done prior to SSF to investigate their effects on lipase production via SSF. The highest lipase activity among the pretreated SB was 0.200 U/, using steam-assisted HCl treated SB, which is lower than the lipase activity produced from the untreated SB, which was 0.413 U/. Scanning Electron Microscope (SEM) imaging showed significant rupture of the SB structure after steam-assisted-HCl pretreatments where the thin walls of the SB pith were wrinkled and collapsed, with no distinctive cell wall structure. The HCl pretreated SB gave the highest crystallinity index (CrI), 91.43%, compared to the untreated, 61.90%. Conversely, microwave and NaOH pretreatments reduced the CrI, which were 46.15% and 43.36%, respectively. In this study, the results obtained indicated that pretreated SB did not improve the lipase production of Schizophyllum commune UTARA1 under SSF. Yew Chee Kam, Siew Ling Hii, Cheryl Yan-Yi Sim, and Lisa Gaik Ai Ong Copyright © 2016 Yew Chee Kam et al. All rights reserved. Cell Adhesion on Polycaprolactone Modified by Plasma Treatment Tue, 19 Apr 2016 10:27:11 +0000 We have investigated the influence of various plasma treatments of electrospun polycaprolactone (PCL) scaffolds on the adhesion and proliferation of human umbilical endothelial cells (HUVEC). The PCL scaffolds were treated in plasmas created in O2, NH3 or SO2 gas at identical conditions. Surface functionalization of plasma-treated samples was determined using X-ray photoelectron spectroscopy. Cell adhesion and morphology were investigated by scanning electron microscopy and the influence of plasma treatment on cell adhesion and viability was evaluated with cell viability assay (MTT assay). The results showed the highest metabolic activity of HUVEC on PCL samples treated with O2 and NH3 plasma. Accordingly, the cells reflected the best adhesion and morphology on O2 and NH3 plasma-treated PCL samples already at 3 h. Moreover, treatment with O2 and NH3 plasma even stimulated endothelial cell proliferation on PCL surfaces by 60% as measured at 24 h, showing significant improvement in endothelialization of this material. Contrarily, SO2 plasma appeared to be less promising in comparison with O2 and NH3 plasma; however, it was still better than without any plasma treatment. Thus, our results importantly contribute to the biocompatibility improvement of the PCL polymer, commonly used for scaffolds in tissue engineering. Nina Recek, Matic Resnik, Helena Motaln, Tamara Lah-Turnšek, Robin Augustine, Nandakumar Kalarikkal, Sabu Thomas, and Miran Mozetič Copyright © 2016 Nina Recek et al. All rights reserved. Bonding Characteristics of Macrosynthetic Fiber in Latex-Modified Fiber-Reinforced Cement Composites as a Function of Carbon Nanotube Content Tue, 19 Apr 2016 08:27:44 +0000 The effect of carbon nanotube content (0, 0.5, 1.0, 1.5, and 2.0% of the cement weight) on the bonding properties of macrosynthetic fiber in latex-modified hybrid fiber cement-based composites (LMHFRCCs) was evaluated. The slump value, compressive strength, and bonding strength were measured for each LMHFRCC. As the carbon nanotube content increased to 1.5%, the bonding properties of the macrosynthetic fiber improved. However, the bonding performance deteriorated at a carbon nanotube content of 2.0%. A decrease in the fluidity of the mix negatively affected the dispersion of the nanotubes in the LMHFRCCs. The addition of carbon nanotubes also affected the relative bonding strength independently of the improvement in compressive strength. Microscopic analysis of the macrosynthetic fiber surfaces was used to understand changes in the bonding behavior. Ji-Hong Jean, Chan Yu, and Chan-Gi Park Copyright © 2016 Ji-Hong Jean et al. All rights reserved. Alginate Production from Alternative Carbon Sources and Use of Polymer Based Adsorbent in Heavy Metal Removal Wed, 06 Apr 2016 12:40:16 +0000 Alginate is a biopolymer composed of mannuronic and guluronic acids. It is harvested from marine brown algae; however, alginate can also be synthesized by some bacterial species, namely, Azotobacter and Pseudomonas. Use of pure carbohydrate sources for bacterial alginate production increases its cost and limits the chance of the polymer in the industrial market. In order to reduce the cost of bacterial alginate production, molasses, maltose, and starch were utilized as alternative low cost carbon sources in this study. Results were promising in the case of molasses with the maximum 4.67 g/L of alginate production. Alginates were rich in mannuronic acid during early fermentation independent of the carbon sources while the highest guluronic acid content was obtained as 68% in the case of maltose. The polymer was then combined with clinoptilolite, which is a natural zeolite, to remove copper from a synthetic wastewater. Alginate-clinoptilolite beads were efficiently adsorbed copper up to 131.6 mg Cu2+/g adsorbent at pH 4.5 according to the Langmuir isotherm model. Çiğdem Kıvılcımdan Moral and Merve Yıldız Copyright © 2016 Çiğdem Kıvılcımdan Moral and Merve Yıldız. All rights reserved. Mechanical Properties of Oil Palm Shell Composites Wed, 06 Apr 2016 11:35:03 +0000 The mechanical properties of oil palm shell (OPS) composites were investigated with different volume fraction of OPS such as 0%, 10%, 20%, and 30% using unsaturated polyester (UPE) as a matrix. The results presented that the tensile strength and tensile modulus of the UPE/OPS composites increased as the OPS loading increased. The highest tensile modulus of UPE/OPS was obtained at 30 vol% of OPS with the value of 8.50 GPa. The tensile strength of the composites was 1.15, 1.17, and 1.18 times higher than the pure UPE matrix for 10, 20, and 30 vol% of OPS, respectively. The FTIR spectra showed the change of functional group of composites with different volume fractions of OPS. SEM analysis shows the filler pull-out present in the composites which proved the poor filler-matrix interfacial bonding. J. Sahari and M. A. Maleque Copyright © 2016 J. Sahari and M. A. Maleque. All rights reserved. Fabrication of Hyaluronan-Poly(vinylphosphonic acid)-Chitosan Hydrogel for Wound Healing Application Wed, 06 Apr 2016 06:20:59 +0000 A new hydrogel made of hyaluronan, poly(vinylphosphonic acid), and chitosan (HA/PVPA/CS hydrogel) was fabricated and characterized to be used for skin wound healing application. Firstly, the component ratio of hydrogel was studied to optimize the reaction effectiveness. Next, its microstructure was observed by light microscope. The chemical interaction in hydrogel was evaluated by nuclear magnetic resonance spectroscopy and Fourier transform-infrared spectroscopy. Then, a study on its degradation rate was performed. After that, antibacterial activity of the hydrogel was examined by agar diffusion method. Finally, in vivo study was performed to evaluate hydrogel’s biocompatibility. The results showed that the optimized hydrogel had a three-dimensional highly porous structure with the pore size ranging from about 25 µm to less than 125 µm. Besides, with a degradation time of two weeks, it could give enough time for the formation of extracellular matrix framework during remodeling stages. Furthermore, the antibacterial test showed that hydrogel has antimicrobial activity against E. coli. Finally, in vivo study indicated that the hydrogel was not rejected by the immune system and could enhance wound healing process. Overall, HA/PVPA/CS hydrogel was successfully fabricated and results implied its potential for wound healing applications. Dang Hoang Phuc, Nguyen Thi Hiep, Do Ngoc Phuc Chau, Nguyen Thi Thu Hoai, Huynh Chan Khon, Vo Van Toi, Nguyen Dai Hai, and Bui Chi Bao Copyright © 2016 Dang Hoang Phuc et al. All rights reserved. Phase Characterization of Cucumber Growth: A Chemical Gel Model Tue, 05 Apr 2016 14:02:40 +0000 Cucumber grows with complex phenomena by changing its volume and shape, which is not fully investigated and challenges agriculture and food safety industry. In order to understand the mechanism and to characterize the growth process, the cucumber is modeled as a hydrogel in swelling and its development is studied in both preharvest and postharvest stages. Based on thermodynamics, constitutive equations, incorporating biological quantities, are established. The growth behavior of cucumber follows the classic theory of continuous or discontinuous phase transition. The mechanism of bulged tail in cucumber is interpreted by phase coexistence and characterized by critical conditions. Conclusions are given for advances in food engineering and novel fabrication techniques in mechanical biology. Bo Li, Xuejing Liu, and Junshi Zhang Copyright © 2016 Bo Li et al. All rights reserved. Preparation and Characterization of Irinotecan Loaded Cross-Linked Bovine Serum Albumin Beads for Liver Cancer Chemoembolization Therapy Wed, 30 Mar 2016 16:26:15 +0000 In this paper, a novel temporary embolization agent for transarterial chemoembolization of liver cancer was developed and tested. The Irinotecan loaded bovine serum albumin (BSA) beads were tried to be used as embolic agent of liver cancer therapy. BSA beads were prepared by a water-in-oil emulsion solvent diffusion method in soya oil and Span 85 was used as the emulsifier. The obtained BSA beads were able to swell 2.37-fold comparing to dried beads. Depending on the equilibrium swelling process, the Irinotecan was loaded with 9.8% total drug concentration and tested. In vitro drug release studies showed that a burst release of Irinotecan was achieved. Eventually BSA beads were completely degraded in a few weeks. CCK-8 assay demonstrated that BSA beads showed no cytotoxicity against human umbilical vein endothelial cells, and the Irinotecan loaded BSA beads showed comparable cytotoxicity against Hep G2, a human liver carcinoma cell line, as the traditional Irinotecan. In a rabbit model, it was found that BSA beads can successfully be transferred to liver and provide occlusion of small arteries. The present investigation suggested that the BSA beads are promising drug carriers and can potentially be used as temporary embolization agents in interventional oncology. Jin Yan, Fei Wang, Jun Chen, Tao Liu, and Tao Zhang Copyright © 2016 Jin Yan et al. All rights reserved. Effect of Heat Assisted Bath Sonication on the Mechanical and Thermal Deformation Behaviours of Graphene Nanoplatelets Filled Epoxy Polymer Composites Mon, 28 Mar 2016 10:26:53 +0000 Graphene nanoplatelets (GNP) filled epoxy composites ranged from 0.2 to 5 vol.% were prepared in this study using simple heat assisted bath sonication for better GNP dispersion and exfoliation. The effects of GNP filler loading via heat assisted bath sonication on the mechanical properties and thermal deformation behaviour were investigated. Improvements on flexural strength and fracture toughness up to 0.4 vol.% filler loading were recorded. Further addition of GNP filler loading shows a deteriorating behaviour on the mechanical properties on the composites. The bulk electrical conductivity of the epoxy composites is greatly improved with the addition of GNP filler loading up to 1 vol.%. The thermal expansion of epoxy composites is reduced with the addition of GNP; however poor thermal stability of the composites is observed. Jin-Luen Phua, Pei-Leng Teh, Supri Abdul Ghani, and Cheow-Keat Yeoh Copyright © 2016 Jin-Luen Phua et al. All rights reserved. Preparation and Property of Xylan/Poly(Methacrylic Acid) Semi-Interpenetrating Network Hydrogel Sun, 27 Mar 2016 13:55:22 +0000 Xylan/poly(methacrylic acid) semi-interpenetrating network hydrogels were synthesized, and these hydrogels were fabricated using various ratios of xylan and methacrylic acid and cross-linked by N,N′-methylenebisacrylamide. The chemical structure and morphology of the prepared hydrogels were characterized by FT-IR spectroscopy and SEM analysis. The porous structure of the prepared hydrogels was found, and the interconnected porous channels increased when the content of xylan was increased in the hydrogels. The hydrogels presented excellent pH sensitivity and swelling reversibility. The dynamic swelling kinetics were also studied, and all obtained results indicated that the prepared xylan/poly(methacrylic acid) semi-IPN hydrogel could be used in biomedical fields, especially for drug release. Xiao-Feng Sun, Yang Feng, Xiaodi Shi, and Yaxiong Wang Copyright © 2016 Xiao-Feng Sun et al. All rights reserved. The Effect of Customized Woven and Stacked Layer Orientation on Tensile and Flexural Properties of Woven Kenaf Fibre Reinforced Epoxy Composites Sun, 27 Mar 2016 12:39:07 +0000 The synthetic fibres have created some issues including risk of inhalation during fabrication process, renewability, biodegradability, and recyclability in composites industry. The usage of biocomposites as a replacement to synthetic fibres is beginning to be widespread. However, it is noted that lesser attention has been devoted to evaluating the mechanical properties of woven kenaf composites at various woven and stacked layer orientation. Thus, the research objective is to identify the effect of woven and stacked layer orientation on tensile and flexural properties of kenaf composites. Two types of fibre orientation are employed; type A contains a higher yarn density and type B contains a low yarn density. The tensile and flexural tests are conducted to analyze the mechanical properties of woven kenaf fibre composites and compare them to random chopped kenaf composites. The fracture interface between fibre and matrix epoxy is further investigated via scanning electron microscope. Type A kenaf improved up to 199% and 177% as compared to random chopped kenaf for flexural strength and tensile strength, respectively. Scanning electron microscopy analysis shows that resin matrix is properly induced into kenaf fibre gap hence giving additional strength to woven kenaf as compared to random chopped kenaf. A. Hamdan, F. Mustapha, K. A. Ahmad, A. S. Mohd Rafie, M. R. Ishak, and A. E. Ismail Copyright © 2016 A. Hamdan et al. All rights reserved. Effect of Wood Fillers on the Viscoelastic and Thermophysical Properties of HDPE-Wood Composite Wed, 23 Mar 2016 10:25:21 +0000 Wood polymer composites (WPC) have well proven their applicability in several fields of the plasturgy sector, due to their aesthetics and low maintenance costs. However, for plasturgy applications, the characterization of viscoelastic behavior and thermomechanical and thermophysical properties of WPC with the temperature and wood filler contents is essential. Therefore, the processability of polymer composites made up with different percentage of wood particles needs a better understanding of materials behaviors in accordance with temperature and wood particles contents. To this end, a numerical analysis of the viscoelastic, mechanical, and thermophysical properties of composite composed of high density polyethylene (HDPE) reinforced with soft wood particles is evaluated. M. Tazi, M. S. Sukiman, F. Erchiqui, A. Imad, and T. Kanit Copyright © 2016 M. Tazi et al. All rights reserved. Influence of Membrane Materials and Operational Modes on the Performance of Ultrafiltration Modules for Drinking Water Treatment Tue, 22 Mar 2016 09:42:24 +0000 Polyethersulfone (PES), polyvinylidene fluoride (PVDF), and polyacrylonitrile (PAN) were prepared to purify micropolluted source water via a pilot-plant test. Integrative devices of in-line coagulation/ultrafiltration (UF) were proposed. Then the treatment performance, operation stability, clean methods, and fresh water recovery rate were assessed. The results showed that the membrane materials and operational modes did not result in significant difference of the removal efficiency of turbidity, , and NH4-N. The uniform distribution porosity, better hydrophilicity, and higher thermal stability of the PES membrane made its specific flux (SF) more than double those of two other membranes; in addition, the transmembrane pressure (TMP) of PES membrane appeared to be the least influenced by temperature change. The hydrophilicity of UF membrane was not a conclusive factor with the critical flux. The inside-out module with higher fouling load presented higher decay rate of SF under fixed flux operation compared with outside-in modules in single filtration duration. The way of gas washing of outside-in modules as a supplement resulted in recovery improvement. The acid-base staggered method of inside-out module to carry out chemical enhanced backwash (CEB) can effectively intensify the effects of backwashing by water. Gongduan Fan, Zhaoyue Su, Rujing Lin, Xiuyong Lin, Renxin Xu, and Wei Chen Copyright © 2016 Gongduan Fan et al. All rights reserved. Preparation and Characterization of Acrylic Primer for Concrete Substrate Application Sun, 20 Mar 2016 09:55:47 +0000 This study dealt with the properties of acrylic primer for concrete substrate using acrylic syrup, made from a methyl methacrylate monomer solution of terpolymers. Terpolymer systems consisting of methyl methacrylate (MMA), 2-ethylhexyl acrylate (2-EHA), and methacrylic acid (MAA) with different chemical composition ratios of MMA and 2-EHA were synthesized through bulk polymerization using azobisisobutyronitrile (AIBN) as initiator. The terpolymer composition is characterized by FTIR, 1H NMR, DSC, TGA, and SEM. The glass transition temperature and the thermal stability increased with increasing amounts of MMA in the terpolymer backbone. The effect of chemical composition of terpolymers on physicomechanical properties of primer films was investigated. However, increasing the amount of MMA in terpolymer backbone increased tensile and contact angle of primer films while elongation at break, water absorption, and bond strength are decreased. In particular, the primer syrup containing 65% 2-EHA has good bonding strength with concrete substrate around 1.1 MPa. El-Sayed Negim, Nurlybayeva Aisha, Grigoriy A. Mun, Rinat Iskakov, Galiya S. Irmukhametova, and Mussylmanbek Sakhy Copyright © 2016 El-Sayed Negim et al. All rights reserved.