共查询到19条相似文献,搜索用时 46 毫秒
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采用溶液相转移法,通过特殊结构的纺丝喷头,制备了品字形PVDF中空纤维膜,讨论了PVDF固含量和芯液组成对品字形膜形态结构和性能的影响。结果表明,随PVDF固含量的增大,品字形膜支撑层空穴变小,膜丝外形融合程度减小,海绵体结构更致密,超滤水通量、透气系数和膜蒸馏通量相应减小,膜丝断裂强力增大;随芯液中溶剂DMAc含量的增加,品字形膜支撑层空穴变小,融合部分海绵体变致密,超滤水通量、透气系数减小,膜蒸馏通量略微提高,膜丝断裂强力增大;优化后的品字形膜的水通量较单芯膜有所降低,但断裂强力显著提高,接近单芯膜的3倍。 相似文献
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为增强膜材料的抗污染性能,通过对于湿相转化法制膜过程中铸膜液及芯液挤出频率及强度的调节,研制出内径呈规则性波动的异径聚偏氟乙烯(PVDF)中空纤维微孔膜.系统研究了异径膜的波动周期、内径比对膜强度、通量及其耐污染性的影响规律.结果表明,随着波动周期的减小、内径比的增加,膜丝的始泡点略有减小,通量显著提高.波动周期为5.0 cm时,膜的内径比从1.0增加到1.4时,纯水通量由180.1 L/(m2·h)增至260.0 L/(m2·h);在卵清蛋白溶液中通量的衰减比由39.1%降至27.5%.内径比为1.3时,膜丝从无波动至波动周期减小到4.0 cm时,纯水通量由180.1 L/(m2·h)提高至234.1 L/(m2·h);在卵清蛋白溶液中通量衰减比由39.1%降至32.7%. 相似文献
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利用固相剪切碾磨技术(S~3M)制备了高β晶含量的聚偏氟乙烯(PVDF)微米级粉体,研究了PVDF粉体的结构形态、粒径及粒径分布,碾磨遍数对粉体结晶结构和介电性能的影响。结果表明,固相力化学反应器强大的挤压和剪切作用可使PVDF中α晶转变为晶,从而有效提高PVDF粉体中β晶相对含量;随碾磨遍数增加,PVDF粉体β晶含量逐渐提高,未碾磨PVDF中的β晶相对含量为37%,碾磨15遍后β晶相对含量达90%以上;同时,介电常数则由1.20增加至10.77,提高约1个数量级。固相剪切碾磨技术为高介电性能材料的制备提供了新途径。 相似文献
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聚偏氟乙烯增强微孔膜的制备研究 总被引:2,自引:1,他引:1
对带衬布的聚偏氟乙烯(PVDF)增强微孔膜(PVDF增强膜)与未带衬布的PVDF微孔膜(PVDF膜)进行了对比分析实验,实验及测试结果表明,通过寻调节制膜条件,便可制备出平均孔径和孔隙率与同一配方的PVDF膜上同的PVDF增强膜,该膜用于蒸馏实验,其截留率与PVDF膜相同,通量还销有增加。 相似文献
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Joung-Man Park Ga-Young Gu Zuo-Jia Wang Dong-Jun Kwon Pyeong-Su Shin Jin-Yeong Choi 《Advanced Composite Materials》2016,25(4):305-316
Electrospun polyvinylidene fluoride (PVDF)-containing carbon nanotubes (CNT) were prepared for use in fabricating actuator materials. Actuating displacement was measured in an electrochemical environment. The electrospun nanofibers were arranged using a drum-type collector, and morphology was investigated using a field emission-scanning electron microscope. The uniformity of dispersion of CNT in the PVDF nanofibers was monitored by electron probe X-ray micro-analysis. Tensile strength and electrical resistivity results were used as an indication of the state of alignment. The electrospun CNT/PVDF nanofiber sheets exhibited better mechanical and electrical properties in the arranged direction. The efficiency and electrical capacities of electrospun CNT/PVDF nanofiber sheet were compared with those of cast PVDF sheets for use in actuator applications in electrochemical environments. The electrospun CNT/PVDF nanofiber sheets exhibited much better actuator performance than PVDF sheets, which are attributed to their superior electrical properties.
Highlights
(1) The interfacial durability of CNT/PVDF nanofibers was enhanced to increase contact area by reinforcing CNT.
(2) The efficiency of CNT/PVDF actuators was improved due to interfacial properties.
(3) Thin thickness drum-type collector was made to enhance nanofiber alignment.
(4) The arranged CNT/PVDF nanofibers exhibited better mechanical and actuating displacements. 相似文献
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采用挤出法制备了PVDF片材;利用单轴拉伸工艺制备了β相含量相对较高的聚偏氟乙烯(PVDF)薄膜;采用偏光显微镜、差示扫描测试仪、X射线衍射仪等仪器,分析了拉伸过程中PVDF薄膜的形貌、结晶度以及结构变化,讨论了不同拉伸温度、不同拉伸比以及不同拉伸速率对薄膜微观结构及β相相对含量的影响。结果表明:PVDF薄膜拉伸过程中α相受外力作用转变成β相。PVDF挤出片材在拉伸温度80℃、拉伸比5倍,拉伸速率50mm/min条件下进行拉伸时,薄膜中β相的相对含量可高达57%。 相似文献
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Peng Jiang Jiafeng Lu Kun Li Xiquan Chen Ruiqi Dan 《Fullerenes, Nanotubes and Carbon Nanostructures》2020,28(5):381-386
AbstractPreparation condition can affect the structure and the properties of nanofiber membrane. In order to explore suitable conditions to prepare the Fe3O4/PVDF nanofiber membrane with good hydrophobicity, the hydrophobicity of Fe3O4/PVDF nanofiber membranes obtained by electrospinning was investigated by changing preparation conditions like weight percentage of Fe3O4 nanoparticles, blending quality concentration of poly (vinylidene fluoride) (PVDF) and Fe3O4 nanoparticles, and positive voltage. And the variations of hydrophobicity of Fe3O4/PVDF nanofiber membranes modified by 1H, 1H, 2H, 2H-perfluorodecyl trimethoxysilane were studied. The results show that the hydrophobicity of Fe3O4/PVDF nanofiber membranes has changed under different preparation conditions. The contact angles of samples increased after a modification by 1H, 1H, 2H, 2H-perfluorodecyl trimethoxysilane, which indicates that the hydrophobicity of Fe3O4/PVDF nanofiber membranes has been enhanced. 相似文献
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基于利用PTFE优异的电荷储存性能,诱导和稳定PVDFβ相的形成以提高复合材料的压电性的思想,采用旋涂工艺和电晕放电方法制备了PVDF/PTFE复合驻极体压电膜,借助压电系数和表面电位测量相结合的方法,研究了制备工艺对复合膜驻极体性能的影响,并结合XRD衍射分析,研究了结晶形态与压电性的关系.结果表明复合膜d33压电系数最高达75pC/N,明显优于PVDF单层膜,其原因与复合膜电荷存储能力的提高及复合膜PVDF微晶中β相含量的增加有关. 相似文献
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PVDF/PS共混微孔膜的制备 总被引:8,自引:0,他引:8
将聚偏氟乙烯和聚砜共混,通过溶胶一凝胶相转化法研制高孔隙率微孔膜.考察了聚合物浓度、PVDF/PS配比、溶剂种类和组成、添加剂浓度、凝胶浴温度和组成、溶剂挥发时间和热处理温度对膜孔径和孔隙率的影响.实验发现:使用DMF/DMAc混合溶剂可提高膜孔径和孔隙率;随LiCl含量的增加,膜孔径和孔隙率逐步增加;凝胶浴温度对膜的水通量没有太大的影响,但凝胶浴组成对膜性能有很大的影响;延长溶刺挥发时间,导致平均孔径减小.选择适当的膜液组成,可制得孔径为0.2~1.0μm,孔隙率达到90%以上的PVDF/PS共混微孔膜,而且共混膜的孔隙率比单组分PVDF膜有大幅度的提高.说明共混化是一种改善PVDF膜性能的有效方法,具有极好的实用开发价值, 相似文献
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