卡波普改性纳米纤维基复合纳滤膜的结构与性能  

Characterization of Nanofiltration Composite Membranes Based on Nanofibrous Substrate Modified by Carbopol

作　　者：杨寅[1] 李雄[1] 神领弟 王敏[1] 王雪芬[1] 朱美芳[1] 

机构地区：[1]东华大学材料学院纤维材料改性国家重点实验室,上海201620

出　　处：《高分子学报》2014年第4期523-531,共9页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号51273042;21174028);上海市教育委员会科研创新重点项目

摘　　要：以仿生胶黏剂卡波普(carbopol,CP)改性的聚丙烯腈(polyacrylonitrile,PAN)纳米纤维膜为基膜,以哌嗪和均苯三甲酰氯分别为水相单体和有机相单体采用界面聚合法制备得到一种功能阻隔层为聚哌嗪酰胺(polypiperazine-amide,PA)的纳米纤维基复合纳滤膜(PAN/CP/PA).傅里叶红外光谱表明CP凝胶中的羧基(—COOH)与PAN纳米纤维层中的氰基(—CN)形成氢键,同时与水相单体哌嗪上的仲胺基形成羧酸铵盐离子键(—COO-H2N+),使得复合纳滤膜各层之间相互作用增强.分别以卡波普改性前后的PAN纳米纤维膜为基膜,采用相同界面聚合工艺制备PAN/PA和PAN/CP/PA复合滤膜,其力学性能测试表明,CP凝胶的引入将PAN纳米纤维基膜与功能阻隔层之间有效黏合在一起,实现了复合膜结构的一体性,整体的断裂强度由15.1 MPa提高至24.2 MPa.对比2种复合膜的盐水过滤性能,PAN/CP/PA复合膜对二价硫酸盐的截留效果与PAN/PA复合膜保持一致,对硝酸盐类和MgCl2的截留效果明显优于PAN/PA复合膜,其缘由归因于CP凝胶层中含有大量的羧基增强了PAN/CP/PA复合纳滤膜荷负电性.同时,CP凝胶本身的亲水性使得PAN/CP/PA复合膜的平均过滤水通量(20.3 L/m2h)与PAN/PA复合膜的平均过滤水通量(20.9 L/m2h)相比基本保持不变.A novel kind of PAN/CP/PA nanofiltration （NF） composite membranes was fabricated by interracial polymerization,while piperazine （PIP） was used as aqueous phase monomer and trimesoyl chloride （TMC） was chosen as organic phase monomer to prepare a polypiperazine-amide （PA） barrier layer based on polyacrylonitrile （PAN） nanofibrous substrate modified by carbopol （CP） gel （a bionic adhesive）. FTIR results showed that hydrogen bonds were formed between carboxyl groups （-COOH） of CP and cyano groups （-CN） of PAN,while ionic bonds of carboxylic acid ammonium salt （-COO-H2N＋） were obtained by neutralization reaction between earboxyl groups of CP and secondary amine groups of PIP. Then interactions of each layer in composite membranes were enhanced. PAN/PA composite membranes and PAN/CP/PA composite membranes were prepared by the same interracial polymerization process based on PAN and PAN/ CP nanofibrous substrates, respectively. Tensile test results indicated that the PAN substrate and PA barrier layer of composite membranes were firmly bonded together by CP gel to form an integrated structure of composite membranes. The resulting tensile strength of composite membranes was increased from 15.1 MPa to 24.2 MPa. Compared with PAN/PA composite membranes,PAN/CP/PA membranes had similar water flux but possessed better rejection rates for different kinds of nitrate salts and MgC12 , which may be attributed to that the PAN/CP/PA composite membrane was strongly negative-charged according to a great amount of earboxyl groups of CP.

关 键 词：纳滤 复合膜 界面聚合 卡波普 结构稳定性 

分 类 号：TQ340.1[化学工程—化纤工业]