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Chinese Journal of Aeronautics 2023年第10期36卷 64-76页

作者： Lingqi ZHU Baozhong ZHU Xiaolong ZHAO Yanan WANG Mengchen LI Jiuyu CHEN Yunlan Sun School of Petroleum and Natural Gas Engineering Changzhou UniversityChangzhou 213164China

Boron has a promising application in the field of propellants due to its high calorific ***,the difficulty of ignition and the poor combustion efficiency of boron(B)have severely limited its efficient *** response to this issue,this paper proposes to improve the ignition and combustion performance of micron-sized boron by the polyvinylidene fluoride(PVDF)*** effect of PVDF content on the B combustion performance was systematically studied using a Thermogravimetry-Differential Scanning Calorimetry(TG-DSC),a Transmission Electron Microscope(TEM),an X-Ray Diffractometer(XRD),a laser Particle Size Analyzer(PSA),and a high-speed *** results show that PVDF can significantly reduce the initial oxidation temperature of B powder and increase its reaction *** the PVDF content is 23wt%,the reaction heat and the combustion intensity of B powder reach the maximum and are significantly higher than those of the uncoated B ***,the fluorination reaction that occurs during the combustion process not only can effectively shorten the combustion time of B powder,but also has a positive effect on its flame intensity and propagation speed,and it significantly reduces B particle agglomeration,which improves the combustion efficiency *** study lays the foundation for the application of PVDF modified B in B-based solid propellants.

关键词： Agglomeration Coating Combustion performance Fluorination reaction polyvinylidene fluoride

EFFECT OF SOLUTION EXTRUSION RATE ON MORPHOLOGY AND PERFORMANCE OF polyvinylidene fluoride HOLLOW FIBER MEMBRANES USING POLYVINYL PYRROLIDONE AS AN ADDITIVE

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Chinese Journal of Polymer Science 2010年第4期28卷 527-535页

作者：陈文清 Makoto Onishi Naoki Abe Department of Environment Science and Engineering College of Architecture and EnvironmentSichuan University SCU-HITACHI Environment Applied Technology Research Center Sichuan University Hitachi Plant Technologies LtdTokyo 170-8466Japan

polyvinylidene fluoride （PVDF） hollow fiber membranes prepared from spinning solutions with different polyvinyl pyrrolidone （PVP） contents （1% and 5%） at different extrusion rates were obtained by wet/dry phase process keeping all other spinning parameters constant. In spinning these PVDF hollow fibers, dimethylacetamide （DMAc） and PVP were used as a solvent and an additive, respectively. Water was used as the inner coagulant. Dimethylformamide （DMF） and water （30/70） were used as the external coagulant. The performances of membranes were characterized in terms of water flux, solute rejection for the wet membranes. The structure and morphology of PVDF hollow fiber were examined by BET adsorption, dry/wet weight method and scanning electron microscopy （SEM）. It is found that the increase in PVP content and extrusion rate of spinning solution can result in the increase of water flux and decrease of solute rejection. The improvements of interconnected porous structure and pore size are induced by shear-thinning behavior of spinning solution at high extrusion rates, which could result in the increase of water flux of hollow fiber membranes. The increase of extrusion rate also leads to the increase of membrane thickness due to the recovery effect of elastic property of polymer chains.

关键词： polyvinylidene fluoride Polyvinyl pyrrolidone Hollow fiber Extrusion rate

PREPARATION AND CHARACTERIZATION OF ION EXCHANGE MEMBRANES BASED ON polyvinylidene fluoride

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Chinese Journal of Polymer Science 2004年第6期22卷 505-510页

作者：严川伟 State Key Laboratory for Corrosion and Protection Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

A new ion exchange membrane based on polyvinylidene fluoride (PVDF) and sulfonated poly(styrene-divinylbenzene) was prepared by in-situ polymerization. The incorporation of sulfonic groups into the polyvinylidene fluoride composite membrane was confirmed by infrared spectroscopy (IR), ion exchange capacity (IEC) and energy dispersive X-ray analysis (EDAX). Area resistance, IEC and water uptake of the treated membrane were evaluated. When 20% of the crosslinked membrane was sulfonated at 80degreesC for 22 h, the PVDF ion exchange membrane can attain 0.8 Omega . cm(2) area resistance in NaCl aqueous solution at 25degreesC, IEC is as high as 2.43 millimoles per grain of the wet membrane. The hydrophilicity of PVDF membrane is also significantly improved after treatment. When 60% of crosslinked membrane was sulfonated at 80degreesC for 6 h, water uptake of the treated membrane can attain 64.7%.

关键词： polyvinylidene fluoride composite membrane sulfonation ion exchange membrane

Preparation and Characterization of the Modified polyvinylidene fluoride (PVDF) Hollow Fibre Microfiltration Membrane

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Journal of Materials Science & Technology 2007年第1期23卷 55-60页

作者： Laizhou SONG Zunju ZHANG Shizhe SONG Zhiming GAO School of Environment ancl Chemical Engineering Yanshan University Qinhuangdao 066004 China School of Material Science and Engineering Tianjin University Tianjin 300072 China

A novel thermally induced graft polymerization technique was used to modify a polyvinylidene fluoride （PVDF） hollow fibre microfiltration membrane. An artificial neural network （ANN） was applied to optimize the prepared condition of the membrane. The optimized dosing of acrylic acid （AA）, acrylamide （AM）, N, N＇- methylenebisacrylamide （NMBA） and potassium persulphate （KSP） designed by ANN was that AA was 40.63 ml/L; AM acted as 6.25 g/L; NMBA was 1.72 g/L and KSP was 1.5 g/L, respectively. The thermal stability of the PVDF modified hollow fibre membrane （PVDF-PAA） was investigated by thermogravimetric （TG） and differential scanning calorimetry （DSC） analysis. The polycrystallinity of the PVDF-PAA membrane was evaluated by X-ray diffraction （XRD） analysis. The complex formation of the modified membrane was ascertained by Fourier transform infrared spectroscopy （FTIR）. The morphology of the PVDF-PAA membrane was studied by environmental scanning electron microscopy （ESEM）. The surface compositions of the membrane were analyzed by X-ray photoelectron spectroscopy （XPS）. The adsorption capacity of Cu^2＋ ion on the PVDF-PAA hollow fibre membrane was also investigated.

关键词： Microfiltration hollow fibre membrane Graft polymerization modification Acrylic acid polyvinylidene fluoride Cu^2+ ion

Dye-sensitized Solar Cells with Higher J_(sc) by Using polyvinylidene fluoride Membrane Counter Electrodes

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Nano-Micro Letters 2011年第3期3卷 195-199页

作者： Xiaodong Li Dingwen Zhang Si Chen Heng Zhang Zhuo Sun Sumei Huang Xijiang Yin Engineering Research Center for Nanophotonics and Advanced Instrument Ministry of Education Department of Physics East China Normal University Advanced Materials Technology Centre Office of the Chief Technology Officer Singapore Polytechnic

A flexible counter electrode(CE) for dye-sensitized solar cells(DSCs) has been fabricated using a micro-porous polyvinylidene fluoride membrane as support media and sputtered Pt as the catalytic ***-conventional structure DSCs have been developed by the fabricated CEs. The Pt metal was sputtered onto one surface of the membrane as the catalytic material. DSCs were assembled by attaching the Ti O2 electrode to the membrane surface without Pt coating. The membrane was with cylindrical pore geometry. It served not only as a substrate for the CE but also as a spacer for the DSC. The fabricated DSC with the flexible membrane CE showed higher photocurrent density than the conventional sandwich devices based on chemically deposited Pt/FTO glass, achieving a photovoltaic conversion efficiency of 4.43%. The results provides useful information in investigation and development of stable, low-cost, simple-design, flexible and lightweight DSCs.

关键词： polyvinylidene fluoride Counter electrode Flexible Dye-sensitized solar cell

Fabrication and Excellent Properties of polyvinylidene fluoride/Graphene Composite Films as Thermal Interface Materials

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Chinese Journal of Chemical Physics 2024年第5期37卷 671-678,I0101页

作者： Yu Zhou Li Zuo Azizur Rahman Bo Hong Hongwei Chen Linchao Zhang Hongbo Ju Junfeng Yang Institutes of Physical Science and Information Technology Anhui UniversityHefei 230601China Key Laboratory of Materials Physics Institute of Solid State PhysicsHefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China Department of Physics University of Science and Technology of ChinaHefei 230026China College of Materials and Chemistry Zhejiang Province Key Laboratory of Magnetic MaterialsChinaJiliang UniversityHangzhou310018China School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China

The growing concern about thermal conductivityand electromagnetic shielding inelectronic equipment has promoted the development of interfacial film *** this work,polyvinylidene fluoride(PVDF)/graphene composite films with different graphene contents were fabricated by high-energy ball milling,cold isostatic pressing,scraping and coating,***-energy ball milling is beneficial to the dispersion of graphene powder,while cold isostatic pressing can greatly enhance thermal conductivity and mechanical strength by reducing the voids in the film and increasing the contact area of graphene *** thermal conductivity,tensile strength and electromagnetic shielding properties of the films were carefully investigated and *** was demonstrated that the thermal conductivity increased from 0.19 W·m^(-1).K^(-1) for pure PVDF to 103.9 W·m^(-1).K^(-1)for the composite film with PVDF:graphene=1:*** the electromagnetic shielding efficiency can reach 36.55 *** prepared PVDF/graphene composite films exhibit outstanding overall performance and have the potential for practical applications.

关键词： Thermal interface material Graphene polyvinylidene fluoride Thermal con-ductivity Electromagnetic interference shielding

Superhydrophobic polyvinylidene fluoride/polyimide nanofiber composite aerogels for thermal insulation under extremely humid and hot environment

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Science China Materials 2021年第5期64卷 1267-1277页

作者： Fan Yang Xingyu Zhao Tiantian Xue Shijia Yuan Yunpeng Huang Wei Fan Tianxi Liu State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringInnovation Center for Textile Science and TechnologyDonghua UniversityShanghai 201620China Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnan UniversityWuxi 214122China

Excellent thermal insulating materials are highly demanded in various applications including buildings, aerospace and sport equipment. However, in practical applications,the performance of thermal insulating materials usually deteriorates under diverse temperature and humidity ***, it is highly essential to construct a bulk material that exhibits outstanding thermal insulation performance under extremely humid and hot environment. In this work, we have conceived a green and effective strategy to fabricate a superhydrophobic and compressible polyvinylidene fluoride/polyimide(PVDF/PI) nanofiber composite aerogel via electrospinning and freeze-drying technique. Interestingly, the PVDF nanofibers and PI nanofibers function as the hydrophobic fibrous framework and mechanical support skeleton,respectively, forming a robust three-dimensional framework with good mechanical flexibility. The PVDF/PI aerogel possesses outstanding superhydrophobic feature(water contact angle of 152°) and low thermal conductivity(31.0 m W m^(-1)K^(-1))at room temperature. Significantly, even at 100% relative humidity(80℃), the PVDF/PI aerogel still exhibits a low thermal conductivity of only 48.6 m W m^(-1)K^(-1), which outperforms the majority of commercial thermal insulating materials. Therefore, the novel PVDF/PI aerogel is promising as an excellent thermal insulating material for the applications in high-temperature and humid environment.

关键词： nanofiber aerogel polyimide polyvinylidene fluoride superhydrophobic thermal insulation

Morphology of polyvinylidene fluoride Based Gel Polymer Electrolytes

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Journal of Shanghai Jiaotong university(Science) 2004年第2期9卷 58-61,70页

作者：田立颖黄小彬唐小真 School of Chemistry and Chemical Technology

Two series of polyvinylidene fluoride (PVDF) based gel polymer electrolytes, with different LiClO 4 or propylene carbonate (PC) content, were prepared and analyzed by infrared spectrometer, differential scanning calorimetry, scanning electron microscope and complex impedance spectrometer. The results show that there are great interactions between PVDF, PC and lithium cations. Both LiClO 4 and PC content lead to evident change of the morphology of the gel polymer electrolytes. The content of LiClO 4 and PC also influences the ionic conductivity of the samples, and an ionic conductivity of above 10 -3 S·cm -1 can be reached at room temperature.

关键词： gel polymer electrolyte polyvinylidene fluoride morphology ionic conductivity

Lead Halide Perovskite Nanocrystals Embedded in Hollow Siliceous Nanospheres and polyvinylidene fluoride with Enhanced Stability in Polar Media

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Lead Halide Perovskite Nanocrystals Embedded in Hollow Silic...

Design of nanofibre interlayer supported forward osmosis composite membranes and its evaluation in fouling study with cleaning

中国化学会第十三届全国分析化学年会

作者： Yipeng Huang Feiming Li Fangyuan Lin Xi Chen Department of Chemistry and the MOF Key Laboratory of Spectrochemical Analysis ＆Instrumentation College of Chemistry and Chemical Engineering Xiamen University

The poor stability of lead halide perovskite nanocrystals（LHP NC） in polar solvents has always been the biggest challenge since its birth, and this problem has tremendously hindered the applications of LHP NCs in many fields[1,2]. To address this problem, LHP NCs embedded in hollow siliceous nanospheres and polyvinylidene fluoride（LHP NCs@HSNs/PVDF） have been synthesized. The hydrophobic LHP NCs@HSNs/PVDF shows strong repulsion to water, and the photoluminescence of LHP NCs@HSNs/PVDF can be retained in ethanol longer than 2 weeks. The polar solvent resisted properties enable the surface processes of LHP NCs@HSNs/PVDF in some common solvents, and this may open an avenue for the applications of LHP NCs in fluorescence imaging, drug delivery and release, sensing, catalysis, etc.

关键词： Lead halide perovskite Hollow siliceous nanosphere polyvinylidene fluoride Polar solvent

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Frontiers of Environmental Science & Engineering 2022年第9期16卷 77-88页

作者： Tao Ma Haiqing Hui Xiaofei You Zhiqiang Pei Miao Tian Bing Wu School of Ecology and Environment Northwestern Polytechnical UniversityXi’an 710072China Singapore Membrane Technology Centre Nanyang Environment and Water Research InstituteNanyang Technological UniversitySingapore 637141Singapore Beijing Origin Water Membrane Technology Co. Ltd.Beijing 101407China Faculty of Civil and Environmental Engineering University of IcelandReykjavik IS-107Iceland

Nanofibre-supported forward osmosis(FO)membranes have gained popularity owing to their low structural parameters and high water ***,the nanofibrous membranes are less stable in long-term use,and their fouling behaviours with foulants in both feed solution(FS)and draw solution(DS)is less *** study developed a nanofibrous thin-film composite(TFC)FO membrane by designing a tiered dual-layer nanofibrous substrate to enhance membrane stability during long-term usage and *** characterisation methods were used to study the effect of the electrospun nanofibre interlayer and drying time,which is the interval after removing the M-phenylenediamine(MPD)solution and before reacting with trimesoyl chloride(TMC)solution,on the intrinsic separation FO *** separation performance of the dual-layer nanofibrous FO membranes was examined using model foulants(sodium alginate and bovine serum albumin)in both the FS and *** dual-layer nanofibrous substrate was superior to the single-layer nanofibrous substrate and showed a flux of 30.2 L/m^(2)/h(LMH)when using 1.5 mol/L NaCl against deionised(DI)water in the active layer facing draw solution(AL-DS)*** the fouling test,the water flux was effectively improved without sacrificing the water/solute selectivity under the condition that foulants existed in both the FS and *** addition,the dual-layer nanofibrous TFC FO membrane was more robust during the fouling test and cleaning.

关键词： Forward osmosis Electro-spinning Interfacial polymerisation Fouling polyvinylidene fluoride

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