耐污染聚酰胺复合纳滤膜的制备及性能

以哌嗪(PIP)和均苯三甲酰氯(TMC)为反应单体,以聚乙烯醇(PVA)为添加剂,通过界面聚合法在聚砜超滤基膜上制备了复合纳滤膜,主要研究了PVA、PIP、TMC单体浓度、热处理条件对复合膜性能的影响,并通过扫描电子显微镜(SEM)、原子力显微镜(AFM)对复合纳滤膜结构和形貌进行表征。研究表明,PVA能够提高膜通量,增强膜亲水性,提高膜表面光滑度。最佳制膜条件是:PIP浓度为3.0 g/L,TMC浓度为1.0 g/L,PVA浓度为0.54 g/L,界面聚合时间为1 min,热处理温度为50℃,热处理时间10 min。制备的纳滤膜在处理Na2SO4、MgSO4、NaCl和MgCl2等4种盐溶液时,其截留性能与陶氏NF-270和星达NFX膜相近,而在深度处理造纸脱墨废水时,也表现出良好的分离性能和耐污染性能。

Preparation and performance research of anti-fouling composite polyamide nanofiltration membrane

A composite polypiperazine-amide nanofiltration membrane,supported by polysulfone(PSF)ultrafiltration membrane,was prepared via interfacial polymerization of piperazine(PIP)and trimesoyl chloride(TMC)in the present of polyvinyl alcohol(PVA).The effects of PVA,PIP and TMC concentration,temperature and time of heat treatment on the composite membrane were studied,and the surface structure and morphology were analyzed by scanning electron microscope(SEM)and atomic force microscopy(AFM).The experiment results showed that increasing PVA content would lead to the increase in the flux of the nanofiltration membrane,make the nanofiltration membrane more hydrophilic,and cause the surface of the nanofiltration membrane smoother.The optimal preparing condition of the composite membrane was 3.0 g/L TMC,1.0 g/L PIP,0.54 g/L PVA,1 min reaction time,and 10 min heat treatment at 50 ℃.The separation performance of self-made nanofiltration membrane,treating the solutions of Na2SO4,MgSO4,NaCl or MgCl2,was similar to that of the commercial nanofiltration membranes,such as Dow NF-270 and Synder.Furthermore,the nanofiltration membrane also showed very good separation and anti-fouling performance in the advanced treatment of deinking wastewater.