Abstract:

PMIA flat-sheet membranes were prepared by non-solvent induced phase inversion method. Specifically, poly(m-phenylene isophthalamide) (PMIA) as polymer materials, lithium chloride (LiCl), polyethylene glycol (PEG-400) and polyvinyl pyrrolidone (PVP) as additives were blended to form casting solution. The effects of polymer concentration, additive type and content on the structures and properties of PMIA membranes were systematically investigated. The results exhibited that with the increase of polymer concentration and LiCl content, the viscosity of the casting solution was enhanced, resulting in the decrease of pore size and pure water flux. While the polymer chains were stretched with the increasing content of PEG, which made pore size and water flux of membranes improved. Then, with increasing PVP additive, the pure water flux of the membrane was increased firstly and then decreased, and the hydrophilicity of the membrane became worse. When the mass fraction of PMIA was 9%, LiCl was 2.8% and PVP was 1.2%, the pure water flux of the membrane was as high as 1421.55 L·m^-2·h^-1·bar^-1 with 80% rejection of bovine serum albumin (BSA) maintained. The high permeability provided a new idea for the preparation of high-performance membrane materials.

Key words: flat-sheet membrane, waste water, separation, polymers, PMIA, additives, pore structure

摘要：

以聚间苯二甲酰间苯二胺（PMIA）为制膜原料，氯化锂（LiCl）、聚乙二醇（PEG-400）和聚乙烯吡咯烷酮（PVP）为添加剂，通过非溶剂诱导相转化法制备了PMIA平板膜，系统考察了聚合物浓度、添加剂种类和含量对PMIA膜结构和性能的影响。结果表明，聚合物浓度和LiCl含量增加，铸膜液黏度增大，导致膜孔径减小，纯水通量降低。而PEG含量的增加，使得聚合物链呈现舒展状态，膜孔径增大，纯水通量升高，亲水性增强。随着PVP含量的增加，膜的纯水通量先升高后降低，膜的亲水性变差。当PMIA的质量分数为9%，LiCl的质量分数为2.8%，PVP的质量分数为1.2%时，膜的纯水通量高达1421.55 L·m^-2·h^-1·bar^-1，对牛血清蛋白（BSA）的截留率为80%，展现出较高的渗透性，为制备高性能膜材料提供了新的思路。

关键词: 平板膜, 废水, 分离, 聚合物, 聚间苯二甲酰间苯二胺, 添加剂, 孔结构