ZrO2纳米粒子原位杂化PVDF膜的制备及其抗污染性能

针对传统聚合物膜抗污染性差的问题,本文从杂化膜结构设计出发,提出将ZrO2纳米粒子的原位制备和聚偏氟乙烯(PVDF)相转化成膜过程有机结合的制膜新方法.该方法将阴离子交换树脂引入到N,N-二甲基甲酰胺(DMF)中,以氧氯化锆为原料,利用阴离子交换树脂提供的―OH与无机盐的阴离子进行交换,得到ZrO2纳米粒子均匀分散的N,N-二甲基甲酰胺溶胶体系.随后将PVDF聚合物溶解到所得的N,N-二甲基甲酰胺溶胶体系中,获得均一、透明的铸膜液.利用X射线光电子能谱(XPS)和透射电子显微镜(TEM)对杂化膜中锆的存在状态和分散性能进行了表征.结果表明,ZrO2纳米粒子均匀分散在PVDF基体中,并且形成的纳米粒子的粒径约为10-20 nm.通过粘度、分相速度和膜形态的测定,研究了成膜机理.结果表明,ZrO2纳米粒子的引入加速了铸膜液成膜过程的分相速度.杂化膜的亲水性能通过接触角测定仪进行了评价.并选择以牛血清蛋白为代表模拟污染物,考察了杂化超滤膜的抗污染性能.结果表明,原位形成的ZrO2纳米粒子显著提高了膜的亲水性,减少了膜对蛋白质的吸附.这种将ZrO2纳米粒子的原位制备和PVDF相转化成膜过程有机结合的制膜新方法在有机-无机杂化膜的制备领域具有显著意义.

In situ Preparation and Antifouling Performance of ZrO2/PVDF Hybrid Membrane

Polymers used in porous membrane manufacture are highly susceptible to adsorption of organic foulants. In this study, a new method for in situ preparation of a poly(vinylidene fluoride) (PVDF) based hybrid membrane is reported. The strategy in this method is to combine an ion-exchange process with a traditional immersion precipitation process. A hydrous ZrO₂ sol was synthesized by the addition of anion-exchange resin to N,N-dimethylformamide (DMF) containing zirconyl chloride. A homogeneous ZrO₂/PVDF casting solution was then obtained by dissolving PVDF in the ZrO₂ sol. The presence and dispersion states of ZrO₂ nanoparticles in the resultant membrane matrix were determined using X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The results indicate that the ZrO₂ nanoparticles were well dispersed throughout the PVDF matrix, and the size of the formed nanoparticles was about 10-20 nm. The membrane formation mechanism was investigated based on the viscosity, precipitation kinetics, and membrane morphology. The results indicate that the introduction of ZrO₂ nanoparticles accelerates phase inversion of the casting solution. The membrane hydrophilicity was determined using contact angle measurements. The antifouling properties were examined using antifouling experiments. The results confirm that the presence of ZrO₂ nanoparticles improves the membrane hydrophilicity and reduces protein adsorption on the membrane. This method for in situ preparation of ZrO₂/PVDF hybrid membranes by combining an ion-exchange process with a traditional immersion precipitation process is valuable in the fabrication and applications of organic-inorganic hybrid membranes.