原位生长制备ZIF-8/聚酰胺双层复合纳滤膜及其染料分离性能

以2,6-二氨基吡啶、均苯三甲酰氯为水相和油相单体,通过界面聚合法制备吡啶功能化聚酰胺(PA-PY)膜,随后利用酰氯水解羧基和吡啶氮原子与锌离子的配位作用,在膜表面原位生长ZIF-8(类沸石咪唑酯骨架材料-8),制备了ZIF-8/聚酰胺(ZIF-8/PA-PY)双层复合纳滤膜。扫描电镜分析结果表明:原位生长法可在PA-PY分离层生成晶型结构完整、致密的ZIF-8层,且随着原位生长时间的增加,ZIF-8层逐渐增厚。ZIF-8/PA-PY双层复合纳滤膜对负电性染料的截留率较高,原位生长时间为12h时,双层复合纳滤膜对甲基蓝截留率为97.9%,刚果红为99.6%。

In-situ growth of ZIF-8 in PY nanofiltration membrane with enhanced dye separation performance

The pyridine functionalized polyamide(PA-PY)membrane was prepared by interfacial polymerization using 2,6-diaminopyridine as aqueous monomers and trimesoyl chloride as organic phase monomers.Next,the carboxyl group and the pyridine nitrogen atom on the surface of the PA-PY membrane were used to coordinate with the zinc ion.ZIF-8 was grown in-situ on the surface of the membrane to prepare a ZIF-8/PY double-layer composite nanofiltration membrane.The results of SEM showed ZIF-8 layer with complete crystal structure could be generated by in-situ growth method on the surface of PA-PY membrane,and the ZIF-8 layer gradually thickened with the increase of in-situ growth time.ZIF-8/PA-PY double-layer membrane had higher rejection rate for negatively charged dyes.When the in-situ growth time was 12 h,the membrane had a methyl blue rejection rate of 97.9%and congo red of 99.6%,respectively.