基于树状分子聚酰胺-胺(PAMAM)的复合纳滤膜制备及性能研究

Preparation and Performance of Composite Nanofiltration Membrane Synthesized from Poly(amidoamine)(PAMAM)

以聚砜超滤膜为支撑膜，通过聚酰胺．胺（PAMAM，G0）与均苯三甲酰氯（TMC）的界面聚合反应制备复合纳滤膜。首先优化了界面聚合过程，并通过场发射扫描电子显微镜（FESEM）进行了膜的表面形貌分析，最后考察了纳滤膜对Na2SO4、不同分子量聚乙二醇及小分子有机物的分离性能。结果表明：较优的纳滤膜制备条件为：PAMAM浓度0．25％（wt），TMC浓度0．3％（wt），界面聚合时间90s，热处理温度60℃。FESEM分析表明经界面聚合反应后，超滤膜表面形成了一层致密的活性层。随着操作压力的增加及Na2SO4浓度的降低，膜对盐的截留率均不断增大。复合纳滤膜可有效截留盐，且其截留分子量（MWCO）处于600-1000g．mol-1。

Composite NF membranes were prepared by interfacial polymerization of poly（amidoamine）（PAMAM, G0） and trimesoyl chloride （TMC） on the substrate of PSF UF membrane. The interfacial polymerization process was optimized and the performance of the membrane was characterized with FESEM, then the prepared NF membranes were used to separate Na2SO4, PEG with different molecular weight and small organic molecules. The experimental results indicate that the optimal preparation conditions are PAMAM concentration 0.25% （wt）, TMC concentration 0.3% （wt）, interfacial polymerization time 90 s, heat treatment temperature 60℃. As indicated by FESEM, selective layer of PA nanofiltration is formed on the substrate layer which is thin and dense after interfacial polymerization. The rejection increases with the increase of operating pressure and decreases with the increase of Na2SO4 concentration. The NF membrane can effectively reject salt ions and the cut-offmolecular weiaht （MWCO） of the resulting membrane is 600-1000 g.mol-1.