壳聚糖-聚乙烯醇共混物/聚丙烯腈复合纳滤膜的研究  

Study on chitosan-polyvinyl alcohol blends/poly (acrylonitrile)(PAN) composite nanofiltration membrane

作　　者：侯进[1] 陈国华[1] 

机构地区：[1]中国海洋大学海洋化学理论与工程技术教育部重点实验室,山东青岛266100

出　　处：《功能材料》2009年第10期1723-1726,共4页Journal of Functional Materials

基　　金：国家重点基础研究发展规划(973计划)资助项目(2003CB615706)

摘　　要：以壳聚糖和聚乙烯醇共混物溶液为铸膜液,涂敷在聚丙烯腈超滤膜上,以戊二醛为交联剂,制备了荷正电壳聚糖-聚乙烯醇共混物/聚丙烯腈复合纳滤膜。探讨了交联时间、交联温度、交联剂浓度、铸膜液浓度等因素的影响,采用单因素实验确定了最佳制膜条件为:以1.5%(质量分数)的壳聚糖和聚乙烯醇共混液为铸膜液,50℃下干燥2h,在戊二醛与无水乙醇质量比为0.75∶50的体系中交联,在40℃水浴中交联4h,50℃下热处理15min。在温度为25℃,流速为30L/h,操作压力为1.0MPa时,对复合膜的性能进行了测试,分别探讨了操作压力和料液类型等因素与膜性能的关系。其纯水渗透系数为5.80L/(h.m2.MPa)。对1000mg/L NaCl、MgCl2、MgSO4和Na2SO4的截留率分别为63.50%、94.30%、81.00%、32.70%,通量分别为3.10、3.65、2.40、2.70L/(h.m2)。对不同类型无机盐的截留顺序为MgCl2>Mg-SO4>NaCl>Na2SO4,呈现阳离子型复合纳滤膜的截留特征。流动电位曲线进一步说明了该复合膜荷正电性,其电压渗系数β为5.68mV/Pa。通过扫描电镜对膜的结构进行了表征,显示了该膜的复合结构。A positively charged composite nanofiltration （NF） membrane is prepared by coating solution of chitosan and polyvinyl alcohol blends on a PAN ultrafiltration （UF） membrane, subsequently crosslinking with glutaraldehyde（GA）. The effects of membrane preparation conditions such as crosslinking time and temperature, GA concentration, etc on membrane properties are studied. The optimal condition is obtained by single-factor experiment as follows. 1.5wt% chitosan and polyvinyl alcohol, cured at 50℃ for 2h, crosslinking at 40℃ for 4h with GA/ethanol=0.75 ： 50（w/w）, heated for 15min at 50℃ finally. At 25℃ and 30L/h of cycling flow and 1.0MPa of operating pressure, the effects of the operation conditions such as operating pressure and type of feed, etc on membrane performance are also investigated. Its pure water permeability is 5.80L/（h · m^z · MPa）. The retention rate to 1000mg/L NaCl, MgCl2, MgSO4 and Na2SO4 solutions are 63.50%, 94. 30%, 81.00% and 32.70%, respectively, with the flux of 3.10, 3.65, 2. 40 and 2.70L/h · m^2, respectively. The retention rate for different salt solutions follows the deceasing order of MgCl2, MgSO4, NaCl, Na2SO4, revealing the characteristic of positively charged NF membrane. Besides, the curve about the streaming potential illuminates the positively charged characteristic of this membrane further, with a pressure osmotic coefficient of 5.68mV/ MPa. The structure characteristic of the NF membrane is characterized by scanning election microscope revealing the composite structure of the NF membrane.

关 键 词：壳聚糖-聚乙烯醇共混物 荷正电 复合纳滤膜 截留率 通量 

分 类 号：TQ028.8[化学工程]