哌嗪嵌入改性聚酰胺复合纳滤膜的研制
Preparation of Polyamide Composite Nanofiltration Membranes Intercalated by Piperazine

选择聚醚酰亚胺(PEI)超滤膜作为支撑层, 选择乙二胺(EDA)为交联剂和均苯三甲酰氯(TMC)反应制备出聚酰胺复合纳滤膜; 选择哌嗪(PIP)等二元胺对该聚酰胺复合纳滤膜进行表面改性, 比较了不同结构二元胺分子对膜纯水通量的影响, 考察了PIP和TMC浓度对膜性能的影响．通过XPS对膜表面化学结构进行表征, 证明PIP与TMC反应生成了聚酰胺．通过扫描电镜和原子力显微镜考察了膜的形貌结构, 结果表明PIP对聚酰胺复合膜的改性并未影响支撑层的结构, 同时降低了膜表面粗糙度．改性后的复合纳滤膜对10 g/L的葡萄糖(相对分子质量180)水溶液的通量和截留率分别为38.3 L/(m2？h)和96.0%．对不同无机盐的截留顺序为：MgSO4(97.4%)＞Na2SO4(97.3%)＞MgCl2(73.9% )＞NaCl(52.4% ), 显示荷负电纳滤膜的特性．对海藻酸钠(SA)与牛血清蛋白(BSA)的通量回复率均在85% 以上, 显示了其良好的耐污染能力．
The polyamide(PA)composite nanofiltration(NF)membrane was prepared using polyetherimide (PEI) ultrafilation membrane as support. Ethylenediamine(EDA)was used as crosslinker and to react with trimesoyl chloride(TMC). The PA composite NF membrane was modified by piperazine(PIP)and other diamines. The effect of different diamine monomers on the pure water flux of membranes and the effect of PIP and TMC concentration on the performance of membranes were investigated. The chemical structure of membrane surface was observed by XPS which indicated that PIP reacted with TMC and generated polyamide. The structure of NF membrane was observed by scanning electron microscopy(SEM)and atomic force microscopy(AFM). SEM images show that PIP modification on the PA composite membrane didn’t change the structure of support. AFM photographs show that the surface of the membrane was smoother than before. The membrane PA-PIP shows that flux and rejection for 10 g/L glucose(relative molecular mass being 180) solution were 38.3 L/(m2 ？h) and 96% respectively. The order of rejection to different salt solutions was MgSO4(97.4%)＞Na2SO4(97.3%)＞MgCl2(73.9%)＞NaCl(52.4%)，revealing the characteristics of negatively charged NF membrane. The flux recovering ratios to both sodium alginate(SA)and bovine serum albumin(BSA)were higher than 85% ，which means that the membrane has good anti-fouling property