基于丹宁酸的低压复合纳滤膜的制备及其染料分离性能

摘要

A series of tannic acid composite nanofiltration membranes was successfully prepared by interfacial polymerization with tannic acid (TA) and isophoronediisocyanate(IPDI) as reaction monomer and polyacrylonitrile (PAN) UF (ultrafilltration) membrane as support layer.FTIR-ATR and SEM's results showed that a defect-free TA separation layer was formed on the PAN substrates.The composite nanofiltration membrane showed a high water flux and excellent dye rejection performance at 0.2 MPa due to loose TA separation layer resulted from the steric-hindrance effect of TA.With the increase of TA concentration,the pure water flux decreased first and then increased,while the rejection of dye appeared contrary trend.The membrane showed a pure water flux up to 15.81 L/(m2 · h) and high methyl blue rejection to 94.5％ when the tannic acid concentration was 0.3 g/L.In addition,the composite nanofiltration membrane prepared by TA presented better anti fouling properties.%以丹宁酸、异佛尔酮二异氰酸酯为反应物,以聚丙烯腈超滤膜为底膜,采用界面聚合法制备低压复合纳滤膜.ATR-FTIR与扫描电镜(SEM)测试结果表明,PAN表面形成无缺陷丹宁酸(TA)分离层;由于单宁酸(TA)多酚基团的空间位阻作用减慢了界面聚合反应速率,所得纳滤膜表层呈现疏松结构,在0.2 MPa低操作压力下,丹宁酸复合纳滤膜的水通量可达15.81L/(m2 h),甲基蓝截留率为94.5％;随着水相单宁酸浓度的增加,复合纳滤膜的甲基蓝截留率呈现先增加后降低的趋势,水通量的变化规律正好相反;抗污染性能测试表明,以丹宁酸制备的复合纳滤膜具有良好的抗污染性能.