基于NaA分子筛的聚酰亚胺-氨酯反渗透复合膜改性研究

Modification of Polyimide-Urethane Reverse Osimosis Composite Membrane Based on NaA Zeolite

将多元胺N,N-二甲基间苯二胺(DMMPD)与4-甲基间苯二胺(MMPD)进行组合,通过二次界面聚合法与多元酰氯5-氧甲酰氯异酞酰氯(CFIC)反应得到一种耐氧化的聚酰亚胺-氨酯反渗透复合膜(MMPD-CFIC@CFIC-DMMPD),该膜具有较好的耐氧化性能.之后,在有机相中掺杂NaA分子筛,制得改性的聚酰亚胺-氨酯反渗透复合膜(MMPD-CFIC/NaA@CFIC-DMMPD).采用傅立叶衰减全反射红外光谱(ATR-FTIR)和X射线光电子能谱(XPS)分析了膜活性分离层的化学组成和结构,并利用扫描电镜(SEM)、原子力显微镜(AFM)以及透射电镜(TEM)观察膜的表面、断面形貌,同时分析了膜的分离性能、耐氯性能与抗有机污染性能.结果表明,NaA分子筛的引入使聚酰亚胺-氨酯反渗透膜的水通量提升,且抗有机污染能力增强,但对膜的耐氧化性能影响不大.

A polyimide-urethane reverse osmosis(RO) composite membrane(MMPD-CFIC@CFIC-DMMPD) was prepared through the reaction of N,N’-dimethyl-m-phenylenediamine(DMMPD) and 4-methyl-phenylenediamine(MMPD) with 5-choroformyloxyisophaloyl chloride(CFIC) via two-step interfacial polymerization method,and this membrane exhibits good oxidation resistance.Then,this MMPD-CFIC@CFIC-DMMPD membrane was further modified with NaA zeolite by doping in the CFIC organic phase.The chemical structure of membrane active layer was examined by the attenuated total reflectance infrared(ATR-IR) and X-ray photoelectronic spectroscopy(XPS).The membrane surface and cross-section morphologies were observed with scanning electronic microscopy(SEM),atomic force microscope(AFM) and transmission electron microscopy(TEM),and the hydrophicity of membrane surface was evaluated by contact angle.Moreover,the separation performance,chlorine resistance and organic foulant resistance properties of the two membranes were systematically investigated.The results showed that the modified polyimide-urethane RO membrane(MMPD-CFIC/NaA@CFIC-DMMPD) presented higher water flux,better organic foulant resistance performance as well as favourite chlorine resistance property than the origin MMPD-CFIC @CFIC-DMMPD membrane due to the incorporating of NaA nanoparticles into the membrane.