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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.
The polyacrylonitrile (PAN) nanofibrous membrane modified by bionic adhesive carbopol (CP) was used as the basement membrane. Piperazine and trimesoyl chloride were used as the monomers for the aqueous phase and the organic phase respectively An interfacial polymerization method was used to fabricate a PAN / CP / PA nanocomposites with polypiperazine-amide (PA) as the functional blocker. Fourier transform infrared spectroscopy (FT-IR) The carboxyl group (-COOH) forms a hydrogen bond with the cyano group (-CN) in the PAN nanofibrous layer while forming a carboxylic acid ammonium salt ionic bond (-COO-H2N +) with the secondary amine group on the piperazine of the aqueous phase so that The interaction between the layers of the composite nanofiltration membrane was enhanced.PAN / PA and PAN / CP / PA composite membranes were prepared by the same interfacial polymerization using PAN nanofibrous membranes modified by Carbopol, The performance test showed that the introduction of CP gel effectively bonded the PAN nanofiber base film with the functional barrier layer to achieve the integrity of the composite film structure with the overall rupture strength increased from 15.1 MPa to 24.2 MPa. Saltwater filtration performance of composite membranes, interception of divalent sulfate by PAN / CP / PA composite membrane and PAN / PA complex The retention of nitrate and MgCl2 was obviously better than that of PAN / PA composite membrane. The reason was attributed to the fact that a large amount of carboxyl groups in the CP gel layer enhanced the negative charge of PAN / CP / PA composite nanofiltration membrane At the same time, the hydrophilicity of CP gel itself makes the average filtration water flux (20.3 L / m2h) of PAN / CP / PA composite membrane and the average filtration water flux (20.9 L / m2h) of PAN / PA composite membrane Than the basic unchanged.