荷正电季铵化壳聚糖/聚醚酰亚胺复合纳滤膜的制备及性能研究

Study on Performances of Positively Charged HACC/PEI Nanofiltration Membrane and Its Preparation

以无纺布增强具有耐溶剂、耐热特性的聚醚酰亚胺(PEI)超滤(UF)膜为支撑层,具有荷正电性和良好成膜性的2-羟丙基三甲基氯化铵壳聚糖(HACC)为功能层,制备了一种荷正电HACC/PEI复合纳滤(NF)膜。考察了聚合物浓度、反应时间、交联剂浓度及交联温度等对所制备的复合纳滤膜性能的影响,并利用扫描电镜(SEM)观察了该复合纳滤膜的表面形貌。结果表明:最佳制备条件下得到的HACC/PEI复合纳滤膜在0.3 MPa、20℃下对MgCl2具有较好的分离效果,其通量和截留率分别为10.9 L/(m2·h)和83.1%;另外,HACC/PEI复合纳滤膜呈现典型的荷正电特征,对二价无机盐具有较高的截留率。

A kind of positively charged and reinforced 2-hydroxypropyltrimethyl ammonium chloride chitosan/ polyetherimide （HACC/PEI） composite nanofiltration （NF） membrane was prepared with the PEI ultrafiltration （UF） membrane as the support layer for its excellent thermal and solvent resistance, the HACC as the functional layer for its positively charged character and good membrane forming ability. Effects of polymer concentration, reaction time, cross-linking agent concentration and cross- linking temperature on performance of the composite NF membrane were studied in detail, and the surface morphologies of the composite membrane were observed by scanning electron microscopy （SEM）. The results show that when the composite membrane is prepared under optimized conditions and tested at 0.3 MPa and 20℃, the composite NF membrane has good effect for MgCI2 separation, its flux and rejection are 10.9 Ll（m2·h） and 83.1% respectively. Moreover, the composite membrane shows classical positively charged membrane character, and has higher rejection rate to bivalent cations.