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以聚氯乙烯(PVC)和聚丙烯腈(PAN)为材质,在特种增容剂存在下共混制膜。实验表明,在所用比例下制备的超滤膜,PVC构成连续相,PAN构成分散相。PVC与PAN的相容性和铸膜液的浓度主要影响膜的孔径,必须以牺牲水通量来换取截留率的提高。PVC分子量及分子量分布除对孔径大小有影响外,同时影响孔径的均一程度。而合适的添加剂(如聚乙二醇,PEG)则既可使膜孔缩小,又可有效地提高开放型膜孔所占的比例,从而使截留率和水通量同时得到明显的提高。
Polyvinyl chloride (PVC) and polyacrylonitrile (PAN) as the material, in the presence of special compatibilizer film. Experiments show that at the ratio used in the preparation of the ultrafiltration membrane, PVC constitutes a continuous phase, PAN constitutes a dispersed phase. The compatibility of PVC with PAN and the concentration of casting solution mainly affects the pore size of the membrane and must be sacrificed for water flux in exchange for an increase in rejection. In addition to the influence of pore size, PVC molecular weight and molecular weight distribution affect the uniformity of pore size. Appropriate additives (such as polyethylene glycol, PEG) can not only reduce the pore size, but also effectively increase the proportion of open pore, so that the rejection rate and water flux at the same time significantly improved.