支撑层与亚胺化条件对聚酰亚胺纳滤膜结构和性能的影响

Influence of the Support Layer and Imidization Conditions on the Structure and Performance of Polyimide Nanofiltration Membrane

支撑层的选择及制备方法改进对均匀分离层的形成及高分离性能纳滤(NF)膜的制备具有重要影响。文中对比了由聚对苯二甲酸乙二酯(PET)膜、聚丙烯腈(PAN)膜、聚四氟乙烯(PTFE)膜为支撑层制备的纳滤膜,通过扫描电镜、热重分析等对聚酰亚胺纳滤(PI NF)膜进行结构表征及分离性能测试。筛选出以PTFE为支撑层获得的聚酰亚胺(PI)纳滤膜具有均匀的分离层。以间苯二胺(MPDA)、均苯四甲酰氯(BTAC)分别作为水相及有机相单体,通过界面聚合法(IP)结合不同亚胺化方式获得PI分离层,筛选出了以化学亚胺化方式获得的PI NF膜具有较高的水通量。结果表明,采用孔径为0.22μm的PTFE作为支撑体,通过化学亚胺化方式,制备的PI NF膜在400 kPa下,具有36.4 L/(m^(2)·h)的水通量。实验结果将为高分离性能PI NF膜的制备提供一定的参考。

The support layer and preparation method have great significance in the forming of nanofiltration(NF) with a uniform separation layer and high separation performance. The NF membranes using poly(ethylene terephthalate)(PET), polyacrylonitrile(PAN), and polytetrafluoroethylene(PTFE) membrane as supporting layer were compared. The polyimide(PI) NF membrane was characterized by SEM, TG, etc., and the nanofiltration performance was tested. The PI NF membrane has a uniform separation layer when PTFE is selected as support layer. Using m-phenylenediamine(MPDA) and pyromellitic chloride(BTAC) as water phase and organic phase monomer, respectively, the PI separation layer was obtained by interfacial polymerization(IP) method combined with different imidization methods. The PI NF membrane obtained by chemical method has a higher water flux. The results show that the PI TFC membrane prepared by chemical imidization has a water flux of 36.4 L/(m^(2)·h) at 400 kPa when using 0.22 μm PTFE support. The experiment results provide a specific reference for preparing high-performance PI NF membranes.