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Ionic Conductivity in Gelatin-Based Hybrid Solid Electrolytes:The Non-trivial Role of Nanoclay

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Journal of Materials Science & Technology 2014年第11期30卷 1096-1102页

作者： Ali Ghadami Nader Taheri Qazvini Nasser Nikfarjam polymer division School of ChemistryCollege of ScienceUniversity of Tehran Biomaterials Research Center (BRC) University of Tehran

In this study, the ionic conductivity behavior in hybrid gelatin-based transparent electrolytes including various types of nanoclays with different size, shape and surface properties was characterized. The effects of nanoclay type and nanoclay concentration as well as different experimental conditions, e.g., pH, temperature and crosslinking were also investigated. In general, the impedance spectroscopy results suggested a non- trivial role for nanoclay. Regardless of the nanoclay type, the ionic conductivity slightly increased first and then decreased by increasing the nanoclay concentration. Furthermore, among sodium montmorillonite （Na＋MMT）, lithium montmorillonite （Li＋MMT）, laponite and hydrotalcite, the hybrid electrolytes prepared by Li＋MMT showed higher ionic conductivity. The results also showed that the chemical crosslinking along with sample preparation at optimum pH, where the gelatin chains might be efficiently adsorbed on exfoliated, negatively charged clay nanosheets, plays an important role. In comparison with the ionic conductivity of the neat sample at room temperature （～10-7 S cm-1）, a ten-fold increase was observed for the crosslinked sample containing 2 wt% of Li^＋MMT prepared at optimum pH 3.5. The conductivity behavior as a function of temperature revealed the obedience with the VogeI-Fulcher-Tammann （VFT） model for all samples, suggesting the important role of segmental motions in the ionic conductivity. Finally, a qualitative explanation was presented for the mechanism of the ionic conduction in gelatin-nanoclay hybrid electrolytes.

关键词： Gelatin Solid-state electrolytes Ionic conductivity Montmorillonitc Laponite Impedance spectroscopy

Polysaccharide Hydrogel Incorporated Carbon Nanofiber Microelectrode for Designing Neural Interfaces

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Journal of Bionic Engineering 2019年第4期16卷 696-710页

作者： Arun Torris Manohar V.Badiger polymer Science and Engineering division CSIR-National Chemical LaboratoryDr.Homi Bhaba RoadPune 411008India

Bionic devices are an integral part of human life,and continuous innovations in their design and functions with the help of nanotechnology has revolutionized the area of neuroscience and ***-interfaces play a key role in bionic devices such as neural implants for efficient transfer of the signal to smart *** report here on the design of a new microelectrode,comprising Carbon Nanofiber (CNF) and a biopolymer,namely carboxymethyl xyloglucan (CMX) hydrogel inside the CNF,which enhances the current density across the interface,Microelectrode was prepared by in-situ cross-linking of CMX inside CNF,with optimized CMX:CNF ratio,resulting in continuous ionic channels confined within the hollow core of *** microscopy images of microelectrodes illustrate the formation ofCMX hydrogel network inside the CNF hollow core without wrapping its *** presence of hydrogel in the CNF was confirmed by Scanning Electron Microscope (SEM) and Transmission Electron Microscopy (TEM).The electrochemical studies indicate the enhancement in charge density as well as the active surface area of the microelectrodes due to the presence ofCMX hydrogel *** microelectrodes have great potential as neural interfaces for designing smart prosthetics with voluntary control.

关键词： carboxymethyl xyloglucan carbon nano fiber hydrogels microelectrode neural interface

pH-responsive AIE-active Polyethylene-based Block Copolymers

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Chinese Journal of polymer Science 2019年第9期37卷 930-935页

作者： Yu Jiang Nikos Hadjichristidis Physical Sciences and Engineering division KAUST Catalysis Center Polymer Synthesis Laboratory King Abdullah University of Science and Technology (KAUST)

A novel synthetic strategy towards pH-responsive aggregation-induced emission (AIE)-active tetraphenylethene (TPE)- functionalized polyethylene-based block copolymers is presented. Tris(3-(4-(l,2,2-triphenylvinyl)phenoxy)propyl)borane was used to initiate the polyhomologation of dimethylsulfoxonium methylide to afford well-defined a-TPE-ω-OH linear polyethylenes (PE). The terminal hydroxyl groups were transformed to atom transfer radical polymerization (ATRP) initiating sites by esterification with bromoisobutyryl bromide, followed by polymerization of rert-butyl acrylate (tBA) to provide TPE-PE-b-PtBA block copolymers. After hydrolysis of the rBu group to COOH group, the corresponding pH-responsive TPE-PE-b-PAA block copolymers were obtained. All synthesized block copolymers revealed AIE behavior either in solution or bulk. Due to the pH-responsivity of PAA chains, the aggregation state at different pH and consequently the fluorescence intensity changed. Also, the synthesized block copolymers exhibited ion-specificity fluorescence properties.

关键词： Polyhomologation ATRP Polyethylene-b-poly(acrylic acid) AIE pH-responsivity Ion-specificity

Fouling and cleaning of membrane——a literature review

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Journal of Environmental Sciences 2000年第2期12卷 116-126页

作者： Zhao, Yan-Jun Wu, Kai-Fen Wang, Zheng-Jun Zhao, Liang Li, Shu-Shen polymer Membrane division Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

Membrane fouling curtails severely the economical and practical implementation of membrane process. The fundamental principles and mechanisms of membrane fouling as well as factors affecting fouling have been summarized in this paper. It also has covered three fouling resistance models and four kinds of approaches to improve membrane performance. Membrane cleaning methods are also discussed including physical, chemical, physico\|chemical and biological methods. In the four groups of basic cleaning methods, biological cleaning has considerable advantages and potentials. Extensive research work should be carried out further to explore and develop new ideas and techniques in the field of membrane cleaning and restoration.

关键词： membrane fouling cleaning CLC number: X703 Document code: A

Effect of poly(vinyl pyrrolidone)on the morphology and physical properties of poly(vinyl alcohol)/sodium montmorillonite nanocomposite films

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Progress in Natural Science:Materials International 2013年第6期23卷 579-587页

作者： Dibyendu Mondal Md.Masud R.Mollick Biplab Bhowmick Dipanwita Maity Mrinal K.Bain Dipak Rana Asis Mukhopadhyay Kausik Dana Dipankar Chattopadhyay Department of polymer Science and Technology University of Calcutta Department of Chemical and Biological Engineering Industrial Membrane Research InstituteUniversity of Ottawa Department of Jute and fiber Technology Institute of Jute TechnologyUniversity of Calcutta Advanced Clay and Traditional Ceramics division Central Glass and Ceramic Research Institute

Nanocomposites of poly(vinyl alcohol)(PVA),poly(vinyl pyrrolidone)(PVP) and sodium montmorillonite(Na+MMT) were prepared by solution mixing and then cast into films.X-ray diffraction analysis and images of transmission electron microscopy establish the formation of PVA/Na+MMT intercalated *** and highly intercalated PVA/PVP/Na+MMT nanocomposite formed in the presence of *** of PVP in PVA/Na+MMT matrix enhances the hydrogen bonding interactions between PVA and Na+MMT and thus increases the mechanical properties and thermal stability of PVA/PVP/Na+MMT nanocomposites compared to PVA/Na+MMT *** interactions between PVA,PVP and Na+MMT were established by the Fourier transform infrared *** moisture absorption tendency of both the PVA and PVA/PVP films reduced after the incorporation of Na+MMT at 75%constant relative *** scanning calorimetry studies show that the presence of PVP and Na+MMT both are responsible for reducing the heat of fusion,and crystallinity of *** flow behavior of the PVA,PVA/PVP and its nanocomposite solutions has been also *** vapor permeability of PVA/PVP/Na+MMT composite films decreased in the presence of nanoclay due to increasing tortuous paths for diffusion.

关键词： Poly(vinyl alcohol) Poly(vinyl pyrrolidone) Sodium montmorillonite Nanocomposites Mechanical properties Water resistance properties

Antistatic coating material consisting of poly (butylacrylate-co-styrene) core-nickel shell particle

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中国有色金属学会会刊：英文版 2009年第B9期19卷 119-123页

作者： Min-Yeong JEONG Byung-Yoon AHN Sang-Koul LEE Won-Ki LEE Nam-Ju JO Department of polymer Science and Engineering Pusan National University Kumho Petrochemical Samsung Corning Precision Glass division of Chemical Engineering Pukyong National University

A transparent and antistatic coating material consisting of polymer core-metal shell particle was prepared. As a polymer core, poly(butylacrylate-co-styrene)s ([P(BA-co-sty)s]) with various compositions of butylacrylate and styrene were synthesized by emulsion polymerization. And the effect of comonomer composition on the thermal property of polymer core particle was investigated. By electroless plating method, the nickel particles were formed and deposited on the surface of P(BA-co-Sty) particles to form P(BA-co-Sty) core-nickel shell composite particles. SEM observation confirms that the nickel particles with size of 15 nm are distributed on the surface of the polymer core particles. The surface resistance of P(BA-co-Sty) core-nickel shell composite is 0.8×108Ω/cm2, enough to act as antistatic coating material.

关键词：复合粒子涂层材料单体组成抗静电苯乙烯丁酯聚合物颗粒镍

ANIONIC SYNTHESIS OF A “CLICKABLE” MIDDLE-CHAIN AZIDE-FUNCTIONALIZED POLYSTYRENE AND ITS APPLICATION IN SHAPE AMPHIPHILES

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Chinese Journal of polymer Science 2013年第1期31卷 71-82页

作者： Kan Yue Jinlin He Chang Liu Mingjun Huang Xue-Hui Dong Kai Guo Peihong Ni Chrys Wesdemiotis Roderic P. Quirk Stephen Z. D. Cheng Wen-Bin Zhang Department of polymer Science College of Polymer Science and Polymer EngineeringThe University of Akron College of Chemistry Chemical Engineeringand Materials ScienceJiangsu Key Laboratory of Advanced Functional Polymer Design and ApplicationSoochow University Department of Chemistry The University of Akron

＂Click chemistry＂ is, by definition, a general functionalization methodology （GFM） and its marriage with living anionic polymerization is particularly powerful in precise macromolecular synthesis. This paper reports the synthesis of a ＂clickable＂ middle-chain azide-functionalized polystyrene （mPS-N3） by anionic polymerization and its application in the preparation of novel shape amphiphiles based on polyhedral oligomeric silsesquioxane （POSS）. The mPS-N3 was synthesized by coupling living poly（styryl）lithium chains （PSLi） with 3-chloropropylmethyldichlorosilane and subsequent nucleophilic substitution of the chloro group in the presence of sodium azide. Excess PSLi was end-capped with ethylene oxide to facilitate its removal by flash chromatography. The raPS-N3 was then derived into a giant lipid-like shape amphiphile in two steps following a sequential ＂click＂ strategy. The copper（I）-catalyzed azide-alkyne cycloaddition between mPS-N3 and alkyne-functionalized vinyl-substituted POSS derivative （VPOSS-alkyne） ensured quantitative ligation to give polystyrene with VPOSS tethered at the middle of the chain （mPS-VPOSS）. The thiol-ene reaction with 1-thioglycerol transforms the vinyl groups on the POSS periphery to hydroxyls, resulting in an amphiphilic shape amphiphile, mPS-DPOSS. This synthetic approach is highly efficient and modular. It demonstrates the ＂click＂ philosophy of facile complex molecule construction from a library of simple building blocks and also suggests that mPS-N3 can be used as a versatile ＂clickable＂ motif in polymer science for the precise synthesis of complex macromolecules.

关键词： Living anionic polymerization Polyhedral oligomeric silsesquioxane (POSS) "Click" chemistry Generalfimctionalization methodology (GFM).

polymer NETWORKS BY MOLECULAR DYNAMICS SIMULATION: FORMATION, THERMAL, STRUCTURAL AND MECHANICAL PROPERTIES

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Chinese Journal of polymer Science 2013年第1期31卷 21-38页

作者： Rong-liang Wu Ting Li Erik Nies division of polymer Chemistry and Materials Department of ChemistryThe Leuven Mathematical Modeling and Computational Science Centre (LMCC) and The Leuven Materials Research Centre (LMRC)Katholieke Universiteit Leuven

A molecular dynamics simulation method is presented and used in the study of the formation of polymer networks. We study the formation of networks representing the methylene repeating units as united atoms. The network formation is accomplished by cross-linking polymer chains with dedicated functional end groups. The simulations reveal that during the cross-linking process, initially branched molecules are formed before the gel point; approaching the gel point, larger branched entities are formed through integration of smaller branched molecules, and at the gel point a network spanning the simulation box is obtained; beyond the gel point the network continues to grow through the addition of the remaining molecules of the sol phase onto the gel （the network）; the final completion of the reaction occurs by intra-network connection of dangling ends onto unsaturated cross-linkers. The conformational properties of the strands in the undeformed network are found to be very similar with the conformational properties of the chains before cross-linking. The uniaxial deformation of the formed networks is investigated and the modulus determined from the stress-strain curves shows reciprocal scaling with the precursor chain length for networks formed from sufficiently large precursor chains （N≥ 20）.

关键词： Crosslinking polymer network Network topology Molecular dynamics Mechanical properties.

Ionic/electronic conductivity regulation of n-type polyoxadiazole lithium sulfonate conductive polymer binders for high-performance silicon microparticle anodes

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Chinese Chemical Letters 2021年第1期32卷 203-209页

作者： Yuanyuan Yu Huihui Gao Jiadeng Zhu Dazhe Li Fengxia Wang Chunhui Jiang Tianhaoyue Zhong Shuheng Liang Mengjin Jiang College of polymer Science and Engineering Sichuan UniversityChengdu 610065China Chemical Sciences division Oak Ridge National LaboratoryOak RidgeTN 37831United States

Low-cost silicon microparticles(SiMP),as a substitute for nanostructured silicon,easily suffer from cracks and fractured during the electrochemical cycle.A novel n-type conductive polymer binder with excellent electronic and ionic conductivities as well as good adhesion,has been successfully designed and applied for high-performance SiMP anodes in lithium-ion batteries to address this *** unique features are attributed to the stro ng electron-withdrawing oxadiazole ring structure with sulfonate polar *** combination of rigid and flexible components in the polymer ensures its good mechanical strength and ductility,which is beneficial to suppress the expansion and contraction of SiMP s during the charge/discharge *** fine-tuning the monomer ratio,the conjugation and sulfonation degrees of the polymer can be precisely controlled to regulate its ionic and electronic conductivities,which has been systematically analyzed with the help of an electrochemical test method,filling in the gap on the conductivity measurement of the polymer in the doping *** experimental results indicate that the cell with the developed n-type polymer binder and SiMP(~0.5 μm) anodes achieves much better cycling performance than traditional non-conductive *** has been considered that the initial capacity of the SiMP anode is controlled by the synergetic effect of ionic and electronic conductivity of the binder,and the capacity retention mainly depends on its electronic conductivity when the ionic conductivity is *** is worth noting that the fundamental research of this wo rk is also applicable to other battery systems using conductive polymers in order to achieve high energy density,broadening their practical applications.

关键词： n-Doping Conductive binder Electronic conductivity Ionic conductivity High-performance silicon microparticle anodes