紫外接枝和界面聚合法修饰的PVDF/PSA耐酸复合纳滤膜的制备及其性能  

Preparation and properties of PVDF/PSA acid-resistant composite nanofiltration membrane modified by UV grafting and interfacial polymerization

作　　者：付维贵[1,2] 翟高伟 刘建超 刘耀威[1,2] 付志远 杜润红 陈熙 陈莉[1,2] FU Wei-gui;ZHAI Gao-wei;LIU Jian-chao;LIU Yao-wei;FU Zhi-yuan;DU Run-hong;CHEN Xi;CHEN Li(School of Material Science and Engineering,Tiangong University,Tianjin 300387,China;State Key Laboratory of Separation Membranes and Membrane Processes,Tiangong University,Tianjin 300387,China)

机构地区：[1]天津工业大学材料科学与工程学院,天津300387 [2]天津工业大学省部共建分离膜与膜过程国家重点实验室,天津300387

出　　处：《天津工业大学学报》2021年第5期1-10,共10页Journal of Tiangong University

基　　金：国家重点研发计划资助项目(2017YFE0114200);天津市教委科研计划项目(2017ZD04,2017KJ052)。

摘　　要：为解决传统分离膜耐酸性较差的问题,基于紫外接枝和界面聚合法制备了一种耐酸性复合聚偏氟乙烯(PVDF)纳滤膜。首先以自制PVDF超滤膜为基膜,通过紫外接枝聚合将丙烯酸(AA)单体接枝于膜表面,先后与水相单体聚乙烯亚胺(PEI)和油相单体1,3-苯二磺酰氯(BDC)发生酰胺化反应和界面聚合反应,得到具有良好耐酸性的聚偏氟乙烯/聚磺酰胺(PVDF/PSA)复合纳滤膜;采用IR、XPS观察复合膜表面化学结构,采用扫描电镜(SEM)和原子力显微镜(AFM)观察膜表面形貌,分析不同接枝时间、单体浓度和反应时间等对复合膜性能的影响,并在酸性环境下进行分离测试,考察其耐酸性能。结果表明:PVDF/PSA复合纳滤膜的最佳制备条件为PEI和BDC的质量分数分别为2.0%和0.2%,接枝时间15 min,反应时间30 s,所制备的复合膜纯水渗透率为20 L/(m^(2)·h·bar)(1 bar=0.1 MPa,下同),对典型二价无机盐MgSO4和Na_(2)SO_(4)的截留率分别为83.4%和85.6%,对染料活性红2的截留率接近100%;在HCl水溶液(pH=1)中浸泡35 d后,复合纳滤膜表面的接触角基本不变,酸性环境下(pH=1),对二价盐MgSO4和Na_(2)SO_(4)的截留率能保持在70%以上,对活性红2的截留率接近100%,染料分离性能未受到酸处理的影响。To solve the problem of poor acid resistance of traditional separation membranes,a polyvinylidene fluoride(PVDF)composite nanofiltration(NF)membrane with acid resistant property was prepared by combining ultraviolet(UV)grafting and interfacial polymerization(IP)methods.Firstly,acrylate(AA)was introduced onto the self-made PVDF membrane surface by UV-initiated free radical polymerization,and then amide reaction with polyethyleneimine(PEI)as aqueous phase monomer followed by IP reaction with 1,3-benzenedisulfonyl chloride(BDC)to obtain composite NF membrane with good acid-resistant property.The chemical structure and morphology of the membrane surfaces were investigated by IR,XPS,SEM and AFM.The effects of grafting time,monomer concentration and reaction time on the performance of the composite membrane were analyzed.Moreover,the separation test was carried out in acidic environment to investigate the acid resistance of the composite NF membrane.The results showed that the optimum preparation conditions of PVDF/PSA composite NF membrane were UV irradiation grafting time of 15 min,the mass fractions of PEI and BDC of 2.0%and 0.2%respectively,and reaction time of 30 s;then the pure water permeability of composite NF membrane prepared was 20 L/(m^(2)·h·bar)(1 bar=0.1 MPa),and the rejection rate for typical inorganic divalent salts of MgSO4 and Na_(2)SO_(4) was 83.4%and 85.6%,respectively,and the rejection rate for the dye Reactive Red 2 was close to 100%.The water contact angle of the composite NF membrane surface was basically stable after soaking in HCl aqueous solution for 35 d,the rejection rate of the composite NF membrane for the divalent salts of MgSO_(4) and Na_(2)SO_(4) can be maintained above 70%,the rejection rate for Reactive Red 2 was maintained at 100%,and the dye separation performance was almost unaffected by acid treatment.

关 键 词：紫外接枝 界面聚合 聚偏氟乙烯 聚磺酰胺 耐酸性 纳滤膜 

分 类 号：TQ051.893[化学工程]