干/湿相转化法制备聚醚酰亚胺纳滤膜

Preparation of Polyetherimide Nanofiltration Membrane by Dry/Wet Phase Inversion

以聚醚酰亚胺(PEI)成膜材料,以N-甲基-2-吡咯烷酮(NMP)为极性溶剂,以乙二醇二甲醚(DGDE)为挥发性不良溶剂,以磷酸(H3PO4)为不挥发性非溶剂,以聚乙二醇(PEG1 000)为添加剂,以水为凝胶介质,通过干/湿相转化法制备不对称纳滤膜.采用均匀设计法对影响膜性能的主要因素进行了研究,建立了膜性能的回归方程,得到了膜性能与各因素之间的定性和定量关系.增加铸膜液中PEI、H3PO4、DGDE的含量,或者延长蒸发时间,均可提高膜的截流性能,同时也减小膜的水通量;增加PEG1000的含量,能有效地提高膜的水通量.

The polyetherimide （PEI） asymmetric nanofihration （NF） membranes are developed with the dry/wet phase inversion methods from the casting solution containing N-methyl-2-pyrrolidone （NMP） as a solvent, diethylene glycol dimethyl ether （DGDE） as a weak nonsolvent additive, H3PO4 as a strong nonsolvent additive and poly ethylene glycol 1000 as an additive. Water is used as a coagulant. The uniform design is used to investigate the main factors that have significant effect on the properties of membrane. The data of experimental results are processed by SPSS software to establish the regression equation. An increase in mass Fraction of PEI, H3PO4, DGDE in casting solution and evaporation time will cause a decrease in the flux of pure water and an increase in the solute rejection rate of membrane. If poly ethylene glycol 1000 into the polymer solution is added, the pure water flux of the membrane will rise.