【摘要】 为在膜表面构造荷电性分离层,本文利用超临界CO₂流体合成聚（苯乙烯-马来酸酐）接枝2-二甲氨基乙胺共聚物,再与1,4-对二氯苄季铵化反应,在PSf膜表面形成季铵盐结构的功能分离层。采用表面红外、扫描电镜、接触角和Zeta电位等对膜表面的化学组成、形貌、水润湿性和荷电性进行表征,研究共聚物浓度对MgCl₂透过性能的影响。改性后,膜表面亲水性增强,存在两个等电点,在p H值为4.5⁷.6时,表现为荷正电性,共聚物溶液浓度在0.010%⁰.0125%（质量分数）时,0.3 MPa渗透通量为35⁴0 L/m2·h,对MgCl₂的截留率为60%⁷5%。结果表明,通过界面季铵化交联能够赋予膜表面一定的荷电性,调整p H值可对不同荷电性的盐进行截留。更多还原

【Abstract】 In order to construct a charge separation layer,supercritical carbon dioxide（scCO₂） was used as reaction medium in synthesizing SMA-g-DMEN copolymer,then the charge modified PSf membranes were fabricated by quaternization crosslinking between N,N- Dimethylethylenediamine and α,α’- Dichloro- p- xylene. Chemical compositions,morphologies,hydrophilicities and charge properties of the membranes were investigated by FTIR-ATR,SEM,water contact angle and Zeta potential,respectively. The results show that the membranes exhibit good hydrophilicity,there are two isoelectric points,at p H from 4.5 to 7.6,the modified membranes show positively charge properties. At the same time,when the copolymer concentration changes between 0.010wt% and 0.0125wt%,at 0.3 MPa,the water flux and the rejection of MgCl₂ is 35- 40 L/m²·h and 60%-75%,respectively. It demonstrates that the membrane is endowed with charge property by quaternization crosslinking and has a salt rejection property by changing p H.更多还原