聚偏氟乙烯纳米多孔膜结构调控及离子传递特性

发布时间：2018-03-26 08:05

本文选题：膜　切入点：结晶　出处：《化工学报》2017年02期

【摘要】：在纳微米尺度调控膜孔结构对发展高性能膜分离材料具有重要意义。使用半结晶性高分子材料聚偏氟乙烯(PVDF),利用非溶剂诱导相分离(NIPS)、蒸汽诱导相分离(VIPS)、溶剂蒸发诱导相分离(EIPS)方法,成功制备了不同形貌的多孔膜。提出了根据聚合物的结晶生长机制调控膜孔结构概念,根据溶剂蒸发时间调控结晶生长。利用SEM和BET对膜孔形貌进行表征,XRD和DSC对结晶进行检测,氢离子(H+)和四价钒离子(VO2+)以及其他常用离子的扩散系数表征传质特性。在溶剂蒸发诱导结晶的过程中,随着溶剂蒸发时间的延长,膜断面的球晶比例逐渐增加,最后至球晶完全融合,膜孔结构发生了显著变化,且膜的结晶度和结晶形态随之发生变化,离子选择性能随膜孔尺寸减小而逐渐增大。
[Abstract]:The regulation of membrane pore structure at nanometer-scale is of great significance for the development of high performance membrane separation materials. Using semi-crystalline polymer polyvinylidene fluoride (PVDF), non-solvent induced phase separation (NIPS), vapor induced phase separation (VIPSN), solvent evaporation, etc. Induced phase separation (EIPS) method, The porous membranes with different morphologies were successfully prepared, and the concept of regulating the pore structure of the membranes according to the crystallization growth mechanism of polymers was proposed. The crystal growth was regulated according to the evaporation time of solvent. The morphology of the film was characterized by SEM and BET. The crystallization was detected by DSC and SEM. The diffusion coefficients of hydrogen ion (H), tetravalent vanadium ion (VO 2) and other commonly used ions were used to characterize the mass transfer characteristics. In the process of solvent evaporation induced crystallization, the spherulite ratio of the film surface increased with the increase of solvent evaporation time. Finally, when the spherulites were completely fused, the pore structure of the membrane changed significantly, and the crystallinity and morphology of the membrane changed, and the ionic selectivity increased gradually with the decrease of the pore size.
【作者单位】：化学工程联合国家重点实验室清华大学;
【基金】：国家自然科学基金项目(21276134)~~
【分类号】：TQ051.893;TQ317

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