聚合物浓度对PSF超滤膜结构和性能的影响  

Effects of polymer concentration on the structure and performance of PSF ultrafiltration membranes

作　　者：马玉新[1,2] 史风梅[3] 马虹[1] 刘春花[1] 亓云鹏 吴淼男[1] MA Yuxin;SHI Fengmei;MA Hong;LIU Chunhua;QI Yunpeng;WU Miaonan(College of Civil Engineering, Heilongjiang University, Harbin 150080, China;Engineering Research Center of Rural Water Safety in Heilongjiang Province, Heilongjiang University, Harbin 150080, China;Rural Energy Institute, Heilongjiang Academy of Agricultural Sciences, Harbin 150086, China)

机构地区：[1]黑龙江大学建筑工程学院,哈尔滨150080 [2]黑龙江大学黑龙江省村镇饮水安全工程技术研究中心,哈尔滨150080 [3]黑龙江省农业科学院农村能源研究所,哈尔滨150086

出　　处：《黑龙江大学自然科学学报》2019年第1期76-83,共8页Journal of Natural Science of Heilongjiang University

基　　金：国家"十三五"重点研发计划课题(2016YFD0501403);黑龙江省教育厅科学技术研究项目(12531503)

摘　　要：以N,N-二甲基乙酰胺(DMAc)为溶剂,将聚砜(PSF)通过浸没沉淀法制备成PSF超滤膜,并利用错流膜评价装置、扫描电子显微镜、接触角测量仪、材料试验机等研究了聚合物浓度对PSF超滤膜结构和性能的影响。研究表明,聚合物浓度的改变会影响膜的结构和性能。随着聚合物比例的增加,超滤膜的纯水通量和接触角下降;牛血清蛋白和胃蛋白酶的截留率增加;膜的孔隙率在聚合物浓度为22%时达到最大值,为49.02%;膜断裂强度随着聚合物浓度的增加呈先增加后减小的趋势,当PSF浓度为20%时,达到最大值11.8 MPa,而断裂伸长率则呈相反的变化趋势,当PSF浓度为18%时,膜的断裂伸长率最小,为8.6%。随着PSF浓度的增加,膜接近上表面部分的海绵状孔比例受到抑制,指状孔逐渐增加。表面活性剂Tween 20和制孔剂LiCl的存在加速了聚砜和溶剂的相分离,使得聚合物浓度的改变对膜结构和性能的影响更加明显。因此,可以通过改变聚合物浓度来调控膜结构,从而改善膜的强度和水处理性能。PSF UF membranes were prepared via non-solvent induced phase inversion method with polysufone(PSf) as a polymer and N,N-dimethyl acetamide(DMAc) as a solvent, respectively. The effects of polymer concentration on the performance and structure of PSF UF membranes were characterized by a cross-flow filtration setup, SEM, contact angle meter and a universal electronic strength measurement. It showed that the change of polymer concentration in the membrane could affect the structure and performance of PSF ultrafiltration membranes. With the increase of PSF concentration, the pure water flux and contact angle values of PSF UF membranes all decreased, while the porosity increased firstly and attained the maximum value of 49.02% when the concentration of PSF was 22%, then decreased when the polymer concentration in the dope further increased. The breaking strength of PSF UF membranes increased firstly and attained the maximum value of 11.8 MPa when the concentration of PSF was 20%, then decreased when the polymer concentration in the dope further increased. And the membrane elongation at the break had the opposite trend compared with the change of membrane breaking strength. The minimum value of membrane elongation at break was 8.6% at the PSF concentration of 18%. The addition of Tween 20 and LiCl could accelerate the instantaneous liquid-liquid phase separation process, which made the effects of polymer concentration on membrane structure and properties more obviously. And it meant that the membrane structures and properties could be adjusted by changing the polymer concentration.

关 键 词：超滤膜 聚砜 聚合物浓度 膜结构 膜性能 

分 类 号：TB3[一般工业技术—材料科学与工程]