聚电解质复合纳滤膜的制备及其截盐性能研究

Study on Preparation of Polyelectrolyte Composite Nanofiltration Membrane and Its Salt Removal Performance

采用静电诱导法,通过铸膜液中带负电的磺化聚醚砜(SPES)和凝固浴中带正电的聚乙烯亚胺(PEI)在相分离时形成的相互吸引作用,在聚醚砜(PES)膜表面形成聚电解质分离层,再经过交联处理和热处理制得聚醚砜复合纳滤膜。结果表明,当铸膜液中SPES/PES比例为4/17,凝固浴中加入的PEI分子量为10000 g/mol时,所制得的纳滤膜在较低测试压力(0.3 MPa)下对硫酸镁(MgSO_(4))和硫酸钠(Na_(2)SO_(4))的截留率分别为91.1%、85.7%,对其溶液的渗透性能分别为71.4 L/(m^(2)·h·MPa)、75.9 L/(m^(2)·h·MPa)。

Polyethersulfone(PES)composite nanofiltration membranes were prepared by electrostatic induction.Through the mutual attraction formed by the negatively charged sulfonated polyethersulfone(SPES)in the casting solution and the positively charged polyethyleneimine(PEI)in the coagulation bath during phase separation,a polyelectrolyte separation layer was formed on the surface of the PES membrane,and then a composite nanofiltration membrane was prepared through cross-linking treatment and heat treatment.The results showed that when the ratio of SPES/PES in the casting solution was 4/17 and the molecular weight of PEI added in the coagulation bath was 10000 g/mol,the prepared nanofiltration membrane had the best salt-cutting performance.The rejection rates for magnesium sulfate(MgSO_(4))and sodium sulfate(Na^(2)SO_(4))under the lower test pressure(0.3MPa)were 91.1%and 85.7%,respectively;the permeability of its solution were 71.4 L/(m~2·h·MPa),75.9 L/(m^(2)·h·MPa),respectively.