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13th Asian chemical Congress

作者： CHIA-HUNG LIN CHI-CHING KUO WEN-CHANG CHEN Department of Chemical Engineering Institute of Polymer Science and Engineering National Taiwan University Department of Chemical Engineering

Morphology and photophysical properties of electrospun(ES)nanofibers prepared from the blends of conjugated rod-coil diblock poly[2,7-(9,9-dihexylfluorene)]-block-Poly(2-vinylpyridine) (PF-b-P2VP)and triblock P2VP-b-PF-b-P2VP copolymers with PEO were *** effects of polymer architecture(diblock ***),polymer composition,and solvent polarity on the fiber

关键词： electrospinning nanofibers rod-coil block copolymer photoluminescence

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New P-type of poly(4-methoxy-triphenylamine)s derived by coupling reactions: Synthesis, electrochromic behaviors, and hole mobility

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Journal of polymer science, Part A: polymer Chemistry 2009年第16期47卷 4037-4050页

作者： Chang, Hui-Wen Lin, Kai-Han Chueh, Chu-Chen Liou, Guey-Sheng Chen, Wen-Chang Institute of Polymer Science and Engineering National Taiwan University 1 Roosevelt Road Taipei 10617 Taiwan Department of Applied Chemistry National Chi Nan University 1 University Road Puli Nantou Hsien 545 Taiwan Department of Chemical Engineering National Taiwan University 1 Roosevelt Road Taipei 10617 Taiwan

Methoxy-substituted poly(triphenylamine)s, poly-4-methoxytriphenylamine (PMOTPA), and poly-N,N-bis(4-methoxyphenyl)-N,N-diphenyl-p- phenylenediamine (PMOPD), were synthesized from, the nickel-catalyzed Yamamoto and oxidative coupling reaction with FeCl3. All synthesized polymers could be well characterized by 1H and 13C NMR spectroscopy. These polymers possess good solubility in common organic solvent, thermal stability with relatively high glass-transition temperatures (TgS) in the range of 152-273 °C, 10% weight-loss temperature in excess of 480 °C, and char yield at 800 °C higher than 79% under a nitrogen atmosphere. They were amorphous and showed bluish green light (430-487 nm) fluorescence with quantum efficiency up to 45-62% in NMP solution. The hole-transporting and electrochromic properties are examined by electrochemical and spectroelectrochemical methods. All polymers exhibited reversible oxidation redox peaks and Eonset around 0.44-0.69 V versus Ag/AgCl and electrochromic characteristics with a color change under various applied potentials. The series of PMOTPA and PMOPD also showed p-type characteristics, and the estimated hole mobility of O-PMOTPA and Y-PMOPD were up to 1.5 x 10 -4 and 5.6 x 10-5 cm2 V-1 s -1, respectively. The FET results indicate that the molecular weight, annealing temperature, and polymer structure could crucially affect the charge transporting ability. This study suggests that triphenylamine-containing conjugated polymer is a multifunctional material for various optoelectronic device applications. © 2009 Wiley Periodicals, Inc.

关键词： Fluorescence

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Optimization of mechanical performance of oxidative nano-particle electrode nitrile butadiene rubber conducting polymer actuator

Optimization of mechanical performance of oxidative nano-par...

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作者： Kim, Baek-Chul Park, S.J. Cho, M.S. Lee, Y. Nam, J.D. Choi, H.R. Koo, J.C. School of Mechanical Engineering Sungkyunkwan University Suwon 440-746 Korea Republic of Department of Chemical Engineering Sungkyunkwan University Suwon 440-746 Korea Republic of Department of Polymer Science and Engineering Sungkyunkwan University Suwon 440-746 Korea Republic of

Present work delivers a systematical evaluation of actuation efficiency of a nano-particle electrode conducting polymer actuator fabricated based on Nitrile Butadiene Rubber (NBR). Attempts are made for maximizing mechanical functionality of the nano-particle electrode conducting polymer actuator that can be driven in the air. As the conducting polymer polypyrrole of the actuator is to be fabricated through a chemical oxidation polymerization process that may impose certain limitations on both electrical and mechanical functionality of the actuator, a coordinated study for optimization process of the actuator is necessary for maximizing its performance. In this article actuation behav iors of the nano-particle electrode polypyrrole conducting polymer is studied and an optimization process for the mechanical performance maximization is performed © 2009 American Scientific Publishers. All rights reserved.

关键词： Conducting polymers

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Block copolymers with a twist

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Journal of the American chemical Society 2009年第51期131卷 18533-18542页

作者： Ho, Rong-Ming Chiang, Yeo-Wan Chen, Chun-Ku Wang, Hsin-Wei Hasegawa, Hirokazu Akasaka, Satoshi Thomas, Edwin L. Burger, Christian Hsiao, Benjamin S. Department of Chemical Engineering National Tsing Hua University Hsinchu 30013 Taiwan Department of Polymer Chemistry Kyoto University Kyoto 615-8510 Japan Department of Materials Science and Engineering Institute for Soldier Nanotechnologies Massachusetts Institute of Technology Cambridge MA 02139 United States Department of Chemistry Stony Brook University Stony Brook NY 11794-3400 United States

Chiral block copolymers (BCPs*) comprising chiral entities were designed to fabricate helical architectures (i.e., twisted morphologies) from self-assembly. A new helical phase (H*) with P622 symmetry was discovered in the self-assembly of poly(styrene)-b-poly(L-lactide) (PS-PLLA) BCPs*. Hexagonally packed, interdigitated PLLA helical microdomains in a PS matrix were directly visualized by electron tomography. The phase diagram of the PS-PLLA BCPs* was also established. Phase transitions from the H* phase to the stable cylinder and gyroid phases were found after long-time annealing, suggesting that the H* is a long-lived metastable phase. In contrast to racemic poly(styrene)-b-poly(D,L-lactide) BCPs, chiral interaction significantly enhances the incompatibility between achiral PS and chiral PLLA blocks in the PS-PLLA BCPs* and can be estimated through the determination of the interaction parameter. © 2009 American chemical Society.

关键词： Block copolymers

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Nylon 6/silica composite and porous nylon 6 nanofibers prepared by electrospinning

Nylon 6/silica composite and porous nylon 6 nanofibers prepa...

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Fiber Society 2009 Fall Meeting and Technical Conference

作者： Shi, Quan Vitchuli, Narendiran Nowak, Joshua McCord, Marian Bourham, Mohamed Zhang, Xiangwu Fiber and Polymer Science Program Department of Textile Engineering Chemistry and Science North Carolina State University RaleighNC27695-8301 United States Department of Nuclear Engineering North Carolina State University RaleighNC27695-7909 United States

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Synthesis and characterization of chitosan-based hydrogels

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International Journal of Biological Macromolecules 2009年第2期44卷 121-127页

作者： Li, Qianzhu Yang, Dongzhi Ma, Guiping Xu, Qiang Chen, Xiangmei Lu, Fengmin Nie, Jun State Key Laboratory of Chemical Resource Engineering Key Lab of Beijing City on Preparation and Processing of Novel Polymer Materials Beijing 100029 China Department of Microbiology Peking University Health Science Center Beijing 100083 China

Biocompatible hydrogels based on water-soluble chitosan-ethylene glycol acrylate methacrylate (CS-EGAMA) and polyethylene glycol diamethacrylate (PEGDMA) were synthesized by photopolymerization. Characterization of morphology, weight loss, water state of hydrogel, pH-sensitivity and cytotoxicity were investigated by scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), X-ray diffraction (XRD), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR), swelling test and methylthiazolydiphenyl-tetrazolium bromide (MTT) assay. The results indicated that the hydrogels were sensitive to pH of the medium, no cytotoxicity for L929 and SW1353, satisfactory for the composite to be used in bioapplications. © 2008 Elsevier B.V. All rights reserved.

关键词： Chitosan

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Optimization of predicted cell voltage & caustic current efficiency in a chlor-alkali membrane cell with application of genetic algorithm

Optimization of predicted cell voltage & caustic current eff...

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作者： Shojaikaveh, N. Ashrafizadeh, S.N. Mohammadi, F. Amerighasrodashti, A. Department of Chemical Engineering Iran University of Science and Technology Narmak Tehran 16846-13114 Iran Iran Polymer and Petrochemical Institute P. O. Box 14965/115 Tehran Iran Department of Chemical Engineering Tarbiat Modares University Tehran 14115-138 Iran

ISBN: (纸本)9781566778077

This paper presents the development of hybrid neural-genetic algorithm model for the prediction of cell voltage and caustic current efficiency (CCE) versus various operating parameters in a lab scale chlor-alkali membrane cell. Each of six process parameters including anolyte pH (2-5), operating temperature (25-90°C), electrolyte velocity (1.3-5.9 cm/s), brine concentration (200-300 g/L), current density (1-4 kA/m2), and run time (up to 150 min) were thoroughly studied at four levels for low caustic concentrations (5 g/L). According to the obtained results, the predicted cell voltages and current efficiencies using GA modeling were found to be very close to the measured values with an average deviation of about 2.82% & 1.77% for test validation data, respectively. It was also found that the developed model is not only capable to predict the voltage and current efficiency but also to reflect the impacts of the other process parameters on the same functions. ©The Electrochemical Society.

关键词： Electrolytes

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Fiber-to-bundle registration of white matter tracts

Fiber-to-bundle registration of white matter tracts

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Medical Imaging 2009 - Image Processing

作者： Xu, Qing Anderson, Adam W. Gore, John C. Ding, Zhaohua Vanderbilt University Institute of Imaging Science United States Department of Electrical Engineering and Computer Science Vanderbilt University United States Department of Biomedical Engineering Vanderbilt University United States Chemical and Physical Biology Program Vanderbilt University United States

ISBN: (纸本)9780819475107

Magnetic resonance diffusion tensor imaging (DTI) is being widely used to reconstruct brain white matter (WM) fiber tracts. For further characterization of the tracts, the fibers with similar courses often need to be grouped into a fiber bundle that corresponds to certain underlying WM anatomic structure. In addition, the alignments of fibers from different studies are often desirable for bundle comparisons and group analysis. In this work, a novel registration algorithm based on fiber-to-bundle matching was proposed to address the above two needs. Using an Expectation Maximization (EM) algorithm, the proposed method is capable of estimating a Thin-Plate- Spline transformation that optimally aligns whole-brain target fiber sets with a reference bundle model. Based on the resulting transformations, the fibers from different target datasets can all be warped into the reference coordinate system for comparisons and group analysis. The fibers can be further automatically labeled according to their similarity to the reference model. The algorithm was evaluated with eight human brain DTI data volumes acquired in vivo at 3T. After registration, the warped target bundles exhibit good similarity to the reference bundles. Quantitative experiments further demonstrated that the detected target bundles agree with ground truth obtained by manual segmentation at a sub-voxel accuracy. © 2009 Copyright SPIE - The International Society for Optical engineering.

关键词： Fibers

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Non-fluorinated superamphiphobic surfaces through sol-gel processing of methyltriethoxysilane and tetraethoxysilane

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Materials Chemistry and Physics 2009年第1期114卷 63-68页

作者： Sheen, Yuung-Ching Chang, Wei-Hsuan Chen, Wen-Chang Chang, Yih-Her Huang, Yuan-Chang Chang, Feng-Chih Department of Applied Chemistry National Chiao Tung University Hsin Chu 30010 Taiwan Institute of Polymer Science and Engineering National Taiwan University Taipei Taiwan Material and Chemical Research Laboratories Industrial Technology Research Institute 30050 Hsin Chu Taiwan

In this study, a simple approach was developed to fabricate an extremely superamphiphobic coating material by the tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) sol-gel derived materials. TEOS and MTES derived moieties were designed for a physical roughness and hydrophobic surface characteristic, respectively. The 29Si solid-state NMR and ESCA analysis showed the coated silica composition was similar to the feeding ratios of TEOS/MTES. The surface structure characterized from SEM and TEM suggested the nanoparticle-based silica surface was observed at a high TEOS/MTES content but changed to a relatively smooth surface at a low TEOS content. The contact angles of water and CH2I2 on the pure TEOS derived coated surface were both 0 due to the hydrophilic Si-OH group. As the MTES composition increased to 25 mol% (T5M3), the coated surface had the contact angles of 149.8 and 133.1 for water and CH2I2, respectively. It revealed that the T5M3-coated surface exhibited both super-hydrophobicity and super-oleophobicity, i.e., superamphiphobicity. Also, it had a relatively low-surface energy (1.38 mJ m-2) considerably lower than that of the F-silane-coated surface with 39.3 mJ m-2. As the MTES composition increased further, both contact angles of water and CH2I2 decreased. Especially, they decreased dramatically at the MTES feeding composition higher than 75 mol%, due to the much less rough surface at a higher MTES composition. The present study suggests that superamphiphobic surface could be achieved by non-fluorinated sol-gel derived silica materials. © 2008.

关键词： Sol-gels

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Covalently stabilized temperature and pH responsive four-layer nanoparticles fabricated from surface 'clickable' shell cross-linked micelles

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Soft Matter 2009年第7期5卷 1530-1538页

作者： Jiang, Xiaoze Zhang, Guoying Narain, Ravin Liu, Shiyong Department of Polymer Science and Engineering Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of China Hefei Anhui 230026 China Department of Chemistry and Biochemistry Biomolecular Sciences Program Laurentian University 935 Ramsey Lake Rd Sudbury ON P3E 2C6 Canada

Alkynyl-terminated double hydrophilic ABC triblock copolymer, poly(oligo(ethylene glycol) monomethyl ether methacrylate)-b-poly(2- (dimethylamino) ethyl methacrylate)-b-poly(2-(diethylamino) ethyl methacrylate) (alkynyl-POEGMA-b-PDMA-b-PDEA), was synthesized via atom transfer radical polymerization (ATRP) by sequential monomer addition using propargyl 2-bromoisobutyrate (PgBiB) as the initiator. The obtained triblock copolymer dissolves molecularly in acidic media and self-assembles into alkynyl surface-functionalized three-layer "onion-like" micelles consisting of a PDEA core, a PDMA inner shell, and a POEGMA corona at alkaline pH. Selective cross-linking of the PDMA inner shell with 2-bis(2-iodoethoxy)ethane (BIEE) results in structurally stable and surface 'clickable' shell cross-linked (SCL) micelles with pH-responsive PDEA cores. This new kind of SCL micelles could be further surface functionalized or conjugated with other azido- terminated polymer chains, functional groups, or biomolecules via Click chemistry. Four layer nanoparticles (SCL-PNIPAM) which have pH-responsive PDEA cores and temperature responsive PNIPAM outer coronas were fabricated from surface 'clickable' shell cross-linked (SCL) micelles and azide-terminated poly(N-isopropylacrylamide) (PNIPAM-N3) using Click chemistry. These novel four layer nanoparticles might act as suitable nano-sized drug delivery vehicles for the encapsulation and release of hydrophobic drugs as a function of either temperature or pH of the environment. © The Royal Society of Chemistry 2009.

关键词： Nanoparticles

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