International Journal of Polymer Science The latest articles from Hindawi Publishing Corporation © 2016 , Hindawi Publishing Corporation . All rights reserved. Nanodeserts: A Conjecture in Nanotechnology to Enhance Quasi-Photosynthetic CO2 Absorption Tue, 26 Jul 2016 09:56:55 +0000 This paper advances “nanodeserts” as a conjecture on the possibility of developing the hierarchical structured polymeric nanomaterials for enhancing abiotic CO2 fixation in the soil-groundwater system beneath deserts (termed as quasi-photosynthetic CO2 absorption). Arid and semiarid deserts ecosystems approximately characterize one-third of the Earth’s land surface but play an unsung role in the carbon cycling, considering the huge potentials of such CO2 absorption to expand insights to the long-sought missing CO2 sink and the naturally unneglectable turbulence in temperature sensitivities of soil respiration it produced. “Nanodeserts” as a reconciled concept not only indicate a conjecture in nanotechnology to enhance quasi-photosynthetic CO2 absorption, but also aim to present to the desert researchers a better understanding of the footprints of abiotic CO2 transport, conversion, and assignment in the soil-groundwater system beneath deserts. Meanwhile, nanodeserts allow a stable temperature sensitivity of soil respiration in deserts by largely reducing the CO2 release above the deserts surface and highlighting the abiotic CO2 fixation beneath deserts. This may be no longer a novelty in the future. Wenfeng Wang, Xi Chen, Yifan Zhang, Jianjun Yu, Tianyi Ma, Zhihan Lv, Jing Zhang, Fanyu Zeng, and Hui Zou Copyright © 2016 Wenfeng Wang et al. All rights reserved. Modeling Based Characterization of Thermorheological Properties of Polyurethane ESTANE™ Mon, 25 Jul 2016 08:43:37 +0000 Shape-Memory Polymers (SMPs) have the ability to be deformed and memorize this deformation until an external activation stimulus (e.g., heat) is applied. Therefore, they have attracted great interest in many areas, especially for applications where reconfigurable structures are required (e.g., Shape-Memory (SM) stents or micro air vehicles). Nevertheless, prior to technical application, the effective thermomechanical behavior of SMPs must be thoroughly understood. In the current contribution, an assessment of thermorheological properties of the commercially available polyurethane system ESTANE is presented. Thermorheological properties were investigated using Dynamic Mechanical Thermal Analysis (DMTA) and complementary uniaxial stress relaxation experiments. Upon material parameter optimization, a finite viscoelastic and incompressible material model was used to model experimentally observed viscoelastic properties. Ehsan Ghobadi, Rakulan Sivanesapillai, Jana Musialak, and Holger Steeb Copyright © 2016 Ehsan Ghobadi et al. All rights reserved. Homogeneous Esterification of Cellulose in the Mixture N-Butylpyridinium Chloride/Dimethylsulfoxide Mon, 18 Jul 2016 15:55:25 +0000 The present study deals with the homogeneous acylation of cellulose with p-nitrobenzoyl chloride in a reaction medium composed of a mixture of 1-butylpyridinium chloride and dimethylsulfoxide (BPyCl/DMSO), in the presence of different bases and under mild conditions. The preparation of cellulose p-nitrobenzoate depending on the reaction conditions, the influences of reaction parameters such as the base type, and the types of cellulose (kraft and microcrystalline) on the products were investigated. Cellulose p-nitrobenzoate with a degree of substitution (DS) in the range from 0.12 to 1.5 was accessible, with a low excess of reagent and for a short reaction time. The cellulose esters were characterized by 1H-NMR, 13C NMR, and FT-IR spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and solubility tests. Lahcen El Hamdaoui, Mohammed El Moussaouiti, and Said Gmouh Copyright © 2016 Lahcen El Hamdaoui et al. All rights reserved. Attapulgite Nanofiber-Cellulose Nanocomposite with Core-Shell Structure for Dye Adsorption Mon, 18 Jul 2016 12:59:49 +0000 Nanocomposite particle used for adsorption has attracted continuous attention because of large specific surface area and adjustable properties from nanocomponent. Herein nanocomposite particle with cellulose core and attapulgite nanofibers shell was prepared. The size of cellulose core was about 2 mm and the thickness of nanofibers shell is about 300 μm. Adsorption capacity of nanocomposite particle to methylene blue can reach up to 11.07 mg L−1 and the best adsorption effect occurs at pH = 8; pseudo-first-order equation and the Langmuir equation best describe the adsorption kinetic and isotherm, respectively; repeated adsorption-desorption experimental results show that 94.64% of the original adsorption capacity can be retained after being reused three times. Xiaoyu Chen, Xiaoxue Song, and Yihe Sun Copyright © 2016 Xiaoyu Chen et al. All rights reserved. Photoinduced Copolymerization of APMP-MMA: The Role of Reactive Hindered Amine APMP Mon, 04 Jul 2016 07:26:53 +0000 4-Acryloyl-1,2,2,6,6-pentamethyl-piperidinol (APMP) is a reactive hindered amine that prolongs the service life of the polymeric materials and exhibits high stability, good resistance to extraction, and low toxicity. In this paper, a photoinduced free radical copolymerization of APMP and methyl methacrylate (MMA) is accomplished at ambient temperature in solution. APMP plays a key role in the copolymerization, owing to the nitroxides generated in situ from the moiety of 1,2,2,6,6-pentamethyl-piperidine under UV irradiation, and mediates the copolymerization, which is confirmed by the linear kinetics. With the increment of initial monomer feed ratios of APMP/MMA, both the copolymerization rate and the average molecular weight increase. According to the reactivity ratios from the extended Kelen-Tüdos (KT) method at high conversion by 1H NMR spectroscopy, a nonlinear model is established and the sequential distribution in the copolymers is also investigated. The dispersion of APMP units is regulated by the feed ratios and reactivity ratios. Ting Zhang, Liuwa Fu, Zhikang Chen, Yanyan Cui, and Xiaoxuan Liu Copyright © 2016 Ting Zhang et al. All rights reserved. Characterization and Optical and Dielectric Properties of Polyvinyl Chloride/Silica Nanocomposites Films Sun, 03 Jul 2016 09:58:59 +0000 Silica nanoparticles were synthesized by a sol-gel method and mixed with different amounts of polyvinyl chloride (PVC) to get nanocomposite films. The samples were characterized by XRD, HR-TEM, SEM, and FTIR. High resolution transmission electron microscopy (HR-TEM) proved that the average particle size of the nanosilica is 15 nm. The scanning electron microscopy (SEM) showed that the nanosilica was well dispersed on the surface of the PVC films. Fourier Transform Infrared (FTIR) spectra for nanocomposite films intimate a significant change in the intensity of the characteristic peaks of the functional group with addition of nanosilica. The optical band gap was found to decrease with the addition of nanosilica while the refractive index increased. The dielectric constant , the dielectric loss modulus , and AC conductivity were also studied. It was found that increases with temperature for all samples, clear dielectric -relaxation observed from dielectric loss around the glass temperature (), and this could be related to micro-Brownian motion of the main PVC chain. The activation energy was calculated, and the AC conductivity could be a hopping one. The results of this work are discussed and compared with previously obtained data. T. Abdel-Baset, M. Elzayat, and S. Mahrous Copyright © 2016 T. Abdel-Baset et al. All rights reserved. Effect of the Volume Fraction of Jute Fiber on the Interlaminar Shear Stress and Tensile Behavior Characteristics of Hybrid Glass/Jute Fiber Reinforced Polymer Composite Bar for Concrete Structures Thu, 30 Jun 2016 13:25:43 +0000 Hybrid glass/jute fiber reinforced polymer (HGJFRP) composite bars were manufactured for concrete structures, and their interlaminar shear stress and tensile performance were evaluated. HGJFRP composite bars were manufactured using a combination of pultrusion and braiding processes. Jute fiber was surface-treated with a silane coupling agent. The mixing ratio of the fiber to the vinyl ester used in the HGJFRP composite bars was 7 : 3. Jute fiber was used to replace glass fiber in proportions of 0, 30, 50, 70, and 100%. The interlaminar shear stress decreased as the proportion of jute fiber increased. Fractures appeared due to delamination between the surface-treated component and the main part of the HGJFRP composite bar. Tensile load-strain curves with 50% jute fiber exhibited linear behavior. With a jute fiber volume fraction of 70%, some plastic deformation occurred. A jute fiber mixing ratio of 100% resulted in a display of linear elastic brittle behavior from the fiber; however, when the surface of the fiber was coated with poly(vinyl acetate), following failure, the jute fiber exhibited partial load resistance. The tensile strength decreased as the jute fiber content increased; however, the tensile strength did not vary linearly with jute fiber content. Chan-Gi Park Copyright © 2016 Chan-Gi Park. All rights reserved. Cross-Linkable Epoxidized Maleinated Castor Oil: A Renewable Resin Alternative to Unsaturated Polyesters Thu, 30 Jun 2016 12:33:53 +0000 As an alternative resin to conventional synthetic unsaturated polyesters (UPEs), epoxidized maleinated castor oil (EMACO) was synthesized in two steps. For this purpose, castor oil was reacted with maleic anhydride at 70°C to obtain maleinated castor oil (MACO). Then, epoxidation of MACO was carried out by using a mixture of formic acid and hydrogen peroxide at 0–5°C. Then, the free carboxyl groups of the synthesized EMACO were further reacted with free epoxide groups of EMACO at 90°C. At the end of the reaction, an unsaturated polyester precursor-prepolymer was obtained (P-EMACO). FTIR and 1H NMR spectroscopic techniques were used to characterize the monomers synthesized. The P-EMACO was then mixed with styrene and cross-linked in the presence of AIBN at 50°C. Thermal and mechanical properties of the final cross-linked product were investigated by thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA) techniques. The degradation onset temperature of the material at which cross-linked X-EMACO loses 5% of its weight was found to be 209°C. Its dynamic and storage modulus at 25°C were determined as 72°C and 1.08 GPa, respectively. These results are higher than some of the different oil based polymers reported in the literature. Yeşim Müge Şahin, Gökhan Çaylı, Jesmi Çavuşoğlu, Emre Tekay, and Sinan Şen Copyright © 2016 Yeşim Müge Şahin et al. All rights reserved. Waste Composite Sensor Designed by Cellulose and Activated Carbon as Ethylene Absorber Thu, 30 Jun 2016 08:20:35 +0000 Activated carbon was successfully derived from scrap tile waste from thermochemical conversion. Chemical and physical modifications were therefore employed to modify the specific surface area and porosity of activated carbon. Cellulose was successfully extracted from palm front. Designation of waste composite was prepared by cellulose and activated carbon. Less than 30 wt% of activated carbon was integrated into cellulose sheet matrix. It was important to note that there is no change in mechanical and morphological properties. Small amount of activated carbon was well dispersed. In order to investigate the feasibility of composite as active packaging, oxygen permeation rate and ethylene gas adsorption ability were preliminary investigated. S. Ummartyotin and C. Pechyen Copyright © 2016 S. Ummartyotin and C. Pechyen. 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.