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以不同相对分子质量及含量的聚乙二醇(PEG)作添加剂制备聚砜(PSF)超滤膜,并考察它们对膜水通量、截留率、机械强度的影响。结果表明,添加剂PEG相对分子质量的提高可显著改善膜通量,提高PEG含量会改变铸膜液体系的相平衡关系,加速相分离的发生,在一定范围内随着PEG含量的提高,膜通量逐渐增大,当PEG的质量分数为15%时膜通量达到峰值,过量的PEG却改变铸膜液的流变性能而延迟液液相分离改变成膜结构,PEG添加量对膜机械性能无明显影响;膜渗透性随凝固浴水温升高先增加后减小,截留率趋于稳定;向凝固浴中加入与溶剂N,N-二甲基甲酰胺可延缓相分离的速度,膜结构由指状孔向海绵状结构过渡。
Polysulfone (PSF) ultrafiltration membranes were prepared by using polyethylene glycol (PEG) with different relative molecular mass and content as additive, and their effects on membrane water flux, retention rate and mechanical strength were investigated. The results showed that the increase of the relative molecular weight of additive PEG can significantly improve the membrane flux and increase the PEG content will change the phase equilibrium of the casting liquid system and accelerate the phase separation. With the increase of PEG content in a certain range, When the mass fraction of PEG is 15%, the membrane flux reaches its peak. Excess PEG changes the rheological properties of the membrane and delays the liquid-liquid phase separation and changes the membrane structure. The addition of PEG affects the membrane mechanical properties The membrane permeability increased first and then decreased with the increase of water temperature in the coagulation bath, and the rejection rate tended to be stable. The addition of N, N-dimethylformamide to the coagulation bath delayed the phase separation, and the membrane The structure transitions from the finger hole to the sponge-like structure.