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PREPARATION OF CARBON NANOFIBERS BY polymer blend TECHNIQUE

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Chinese Journal of Reactive polymers 2007年第Z1期 108-111页

作者： LING Fen YANG Pengfei PAN Wei YANG Shenglin LI Guang College of Material Science and Engineering, Donghua University, Shanghai 200051, China.

The polymer blend technique is a novel method to produced carbon nanofibers. In this paper, we have prepared fine carbon fibers and porous carbon materials by this technique, and we will discuss the experiment results... 详细信息

关键词： Carbon nanofibers polymer blend Wet-spinning Compatibility Morphology.

MISCIBILITY IN COpolymer/HOMOpolymer blendS

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Chinese Journal of polymer Science 1988年第3期6卷 193-198页

作者：江明 Fudan University Institute of Material Science Shanghai

In order to study the miscibility of a copolymer with its corresponding homopolymers, varieties of multicomponent polymers including simple graft, muhibranch, diblock, triblock and four-arm block copolymers and so-called ABCPs were synthesized and characterized. The morphologies of the blends comprising the copolymers and the corresponding homopolymers were examined by electron microscopy. It is concluded that besides molecular weight, architecture of a copolypaers has apparent effect on the miscibility, i.e. the more complex is molecular architecture, the greater is conformation restriction in microdomain formation and the less is solubility of homopolymer in corresponding domains. In addition, a density gradient model is suggested for describing the segment distribution of the bound and free chains in block-homopolymer systems. Using this model, Helfand’s theory is extended to the blends of copolymer and homopolymer predicting the miscibility which is in good agreement with the experimental results.

关键词： polymer blend Morphology Miscibility Chain-architectural effect

EXPERIMENTAL INVESTIGATION OF THE LOW CYCLE FATIGUE CRACK PROPAGATION IN PC/ABS polymer blendS

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Acta Mechanica Solida Sinica 2001年第4期14卷 344-348页

作者： Notomi M. Kishimoto K. Department of Mechanical Engineering Meiji UniversityKanagawa 214Japan Department of Mechanical and Intelligent Systems Engineering Tokyo Institute of TechnologyTokyo 152Japan

Low cycle fatigue crack propagation (FCP) behavior of two PC/ABSblends with a weight ra- tio of PC to ABS being 80/20 and 60/40,respectively, is investigated. Experiments are carried out by usingstandard compact tension (CT) specimens. The fracture surfaces areexamined with a scanning electron mi- croscope (SEM). It is shownthat the FCP resistance of PC/ABS blend with 20/100 ABS particles ishigher than that of PC/ABS blend with 40/100 ABS particles. It isfound that proper ABS particle content can result in the tougheningof PC/ABS blends through particle cavitation and shear yielding inmatrix.

关键词： polymer blend polycarbonate acrylonitrile-butadiene-styrene fatigue

Formation of biomimetic hierarchical nanostructure in homopolymers and block copolymer ternary blend particles

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Particuology 2022年第5期20卷 98-109页

作者： Shu Kikuchi Ryoka Shoji Shinji Kanehashi Guanghui Ma Kenji Ogino Graduate School of Bio-Applications and Systems Engineering Tokyo University of Agriculture and Technology2-24-16 NakachoKoganei-shiTokyo 184-8588Japan Institute of Global Innovation Research Tokyo University of Agriculture and Technology2-24-16 NakachoKoganei-shiTokyo 184-8588Japan State Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100080China

In order to mimic hierarchical nanostructures in nature,particles of polymer blends consisting of poly(4-butyltriphenylamine)(PBTPA),poly(methyl methacrylate)(PMMA)and PBTPA-block-PMMA were fabricated by a solvent evaporation *** of the molecular weight and the chemical composition of PBTPA-b-PMMA,molecular weights of homopolymers,and the composition of the blend on the morphology were *** polymer blend particle consisting of PBTPA and PMMA homopolymers exhibited thermodynamically favored core-shell structure,in which more hydrophilic PMMA-shell surrounded *** addition of 10 wt%of PBTPA-b-PMMA caused the morphological transition from core-shell toJanus or inversed core-shell,in which PBTPA-shell surrounded PMMA-core,depending on the molecular weight of PBTPA segment in *** the molecular weight of PMMA segment was higher than that of PMMA homopolymer,watermelon-like particles in which small PBTPA domain less than 80 nm dispersed in the PMMA domain surrounded by PBTPA shell were *** the ratio of PBTPA-b-PMMA increased,the interface of the macrophase separation became *** 50 wt%of the PBTPA-b-PMMA,only microphase separation was *** measurement of interfacial tension by pendant drop method demonstrated that PBTPA-b-PMMA lower the interfacial tension between PBTPA and the aqueous phase to the value similar to that of PMMA with the aqueous phase.

关键词： Microsphere Hierarchical structure polymer blend Block copolymer Solvent evaporation Phase separation

UNIQUE EVOLUTION OF SPATIAL AND DYNAMIC HETEROGENEITIES ON THE GLASS TRANSITION BEHAVIOR OF PVPh/PEO blendS

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Chinese Journal of polymer Science 2012年第6期30卷 900-915页

作者：孙平川 Key Laboratory of Functional polymer Materials Ministry of EducationCollege of ChemistryNankai University

Glass transition behavior of hydrogen bonded polymer blends of poly（vinyl phenol）（PVPh） and poly（ethylene oxide）（PEO） is systematically investigated using normal differential scanning calorimetry （DSC） and recently developed multifrequency temperature-modulated DSC （TOPEM）, in combination with Fourier transform infrared spectroscopy （FTIR） and nuclear magnetic resonance （NMR） techniques, focusing on the effect of the PEO molecular weight on the spatial and dynamic heterogeneity. It is found, for the first time, that both the glass transition temperature （Tg） and activity energy （Ea） of the blends strongly depend on PEO molecular weight, and a common turning point, which separates the rapid and slow increasing regions, can be found. The interchain hydrogen bonding interactions, both determined by FTIR measurements and obtained from the Kwei equation, decrease with increasing PEO molecular weight, indicating a decrease of the componential miscibility. A series of parameters related to the microscopic spatial and dynamic heterogeneity, such as the activity energy, fragility, nonexponential factor and the size of cooperatively rearranging regions, are calculated from frequency dependency complex heat capacity measured using TOPEM. It is found that each of these parameters monotonically changes with increasing the PEO molecular weight during the glass transition process, demonstrating that hydrogen bonding interaction is the key factor in controlling the spatial and dynamic heterogeneity, thus the glass transition. NMR relaxation results reveal the existence of obvious phase separation large than 5 nm, implying that the cooperatively rearranging regions should be closely related to the interphase region between the two components. The above obtained origin and evolution of spatial and dynamic heterogeneity provide a new insight into the glass transition behavior of polymer blends.

关键词： Glass transition polymer blend DSC FTIR Solid-state NMR.

blend MEMBRANES FOR DIRECT METHANOL AND PROTON EXCHANGE MEMBRANE FUEL CELLS

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Chinese Journal of polymer Science 2012年第4期30卷 548-560页

作者： Perumal Bhavani Dharmalingam Sangeetha Department of Chemistry Anna UniversityChennai 25India

Sulphonated polystyrene ethylene butylene polystyrene （SPSEBS） prepared with 35% sulphonation was found to be highly elastic and enlarged up to 300%-400% of its initial length. It absorbed over 110% of water by weight. A major drawback of this membrane is its poor mechanical properties which are not adequate for use as polymer electrolytes in fuel cells. To overcome this, SPSEBS was blended with poly（vinylidene fluoride）（PVDF）, a hydrophobic polymer. The blend membranes showed better mechanical properties than the base polymer. The effect of PVDF content on water uptake, ion exchange capacity and proton conductivity of the blend membranes was investigated. This paper presents the results of recent studies applied to develop an optimized in-house membrane electrode assembly （MEA） preparation technique combining catalyst ink spraying and assembly hot pressing. Easy steps were chosen in this preparation technique in order to simplify the method, aiming at cost reduction. The open circuit voltage for the cell with SPSEBS is 0.980 V which is higher compared to that of the cell with Nation 117 （0.790 V）. From this study, it is concluded that a polymer electrolyte membrane suitable for proton exchange membrane fuel cell （PEMFC） and direct methanol fuel cell （DMFC） application can be obtained by blending SPSEBS and PVDF in appropriate proportions. The methanol permeability and selectivity showed a strong influence on DMFC performance.

关键词： Fuel cell Impedance polymer blend Proton conductivity.

Fabrication of Highly Anisotropic and Interconnected Porous Scaffolds to Promote Preosteoblast Proliferation for Bone Tissue Engineering

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Chinese Journal of polymer Science 2021年第9期39卷 1191-1199页

作者： Ya-Hui Liu Wei Liu Zi-Li Zheng Xin Wei Nouman Ali Shah Hao Lin Bai-Song Zhao Shi-Shu Huang Jia-Zhuang Xu Zhong-Ming Li College of polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065China Department of Anesthesiology Guangzhou Women and Children's Medical CenterGuangzhou 510623China Department of Orthopaedic Surgery West China HospitalSichuan UniversityChengdu 610065China

Mimicking the complex structure of natural bone remains a challenge for bone tissue *** this study,a novel processing strategy was developed to prepare the bone-like scaffolds that are featured by highly oriented and fully interconnected *** type of biomimetic scaffolds was evolved from solid phase stretching of immiscible polycaprolactone(PCL)/poly(ethylene oxide)(PEO)blends with cocontinuous structure and the pore morphology was inherited from selective extraction of water soluble PEO *** pore anisotropy was readily tuned by varying the stretching strain without loss of *** promotion in preosteoblast proliferation,alkaline phosphatase activity and osteogenic gene expression was observed in the oriented porous scaffolds compared to the isotropic porous *** oriented architecture provided a topographical cue for aligned growth of preosteoblasts,which activated the Wnt/β-catenin signaling *** proposed strategy enriches the toolbox for the scaffold design and fabrication for bone tissue engineering.

关键词： Porous scaffold Pore anisotropy polymer blend Co-continuous structure Tissue engineering

polymeric artificial solid/electrolyte interphases for Li-ion batteries

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Progress in Natural Science:Materials International 2015年第6期25卷 563-571页

作者： Nae-Lih Wu Yu-Ting Weng Fu-Sheng Li Nai-Hsuan Yang Chin-Lung Kuo Dong-Sheng Li Deprtment of Chemical Engineering National Taiwan University Department of Materials Science and Engineering National Taiwan University

During the operation of Li-ion batteries(LIBs),solvent and electrolyte decomposition takes place at the electrode surface to form a so-called solid-electrode interphase(SEI) *** physical structure and chemical composition of the SEI exert profound effects on various aspects of the electrode performance of the batteries.A new concept of forming polymeric artificial SEIs(A-SEIs) based on rational design of multifunctional polymer-blend coating to achieve favorable electrode/A-SEI/electrolyte interfacial properties is *** examples using binary and ternary polymer blends to form mechanically robust and highly Li-ion permeable surface coatings with selected functionalities in the cases of graphite and silicon–graphite composite electrodes have demonstrated greatly enhanced capacity,rate and cycle *** the rich chemistry available from polymer blends,this surface preconditioning approach holds great promise for improving the performance of various negative electrodes to meet the requirements for advanced LIBs.

关键词： Li ion battery Solid electrolyte interphase Surface modification polymer blend

Polyaniline-poly(vinylidene fluoride) blend microfiltration membrane and its spontaneous gold recovery application

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Science China Chemistry 2018年第1期61卷 118-126页

作者： Gang Liu Tangliu Yan Yuanzhao Wu Xiaohui Yi Bin Chen Run-Wei Li CAS Key Laboratory of Magnetic Materials and Devices Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Ningbo 315201 China Zhejiang Province Key Laboratory of Magnetic Materials and Applied Technology Ningbo Institute of Materials Technology and Engineering. Chinese Academy of Sciences Ningbo 315201 China University of Chinese Academy of Sciences Beijing 100049 China

Structural regular polyaniline was synthesized via a modified-chemical oxidative polymerization reaction. Highly hydrophilic polyaniline(PANi) and polyaniline-poly(vinylidene fluoride) blend(PANi-PVDF) membranes were prepared by solution casting and phase inversion techniques. Both of the mechanical and filtration properties of the membranes depend on the polymer composition and doping level of the blends. The elasticity of the membrane is greatly improved upon introducing poly(vinylidene fluoride) into the blend. The water permeability of the blend membranes is further enhanced when the membranes are doped with hydrochloric acid. The PANi-PVDF blend membranes are capable of recovering metallic gold from the acid/halide leaching streams spontaneous and sustainably, and are promising candidates for wastewater treatments in electronic industries.

关键词： polyaniline poly(vinylidene fluoride) polymer blend microfiltration membrane gold recovery