流动电位法表征纳滤膜的表面动电特性  

Characterization of Surface Electrokinetic Property of Nanofiltration Membranes by Streaming Potential Measurements

作　　者：王薇[1] 李国东[1] 杜启云[1] 

机构地区：[1]天津工业大学中空纤维膜材料与膜过程教育部重点实验室,天津300160

出　　处：《材料导报》2008年第8期131-135,共5页Materials Reports

基　　金：国家重点基础研究发展计划(2006CB708602);天津市科技发展计划项目(06YFGZS1101700);天津市高等学校科技发展基金(20060516)

摘　　要：测定了纳滤膜在电解质水溶液中的流动电位。考察了盐溶液浓度、操作压力、离子种类和价态等对膜表面流动电位的影响。通过流动电位的测定可以得到纳滤膜的表面动电参数:Zeta电位和表面电荷密度。研究了浓度和压力对Zeta电位和电荷密度的影响。结果表明:纳滤膜表面流动电位的绝对值(|ΔE|)和表面Zeta电位的绝对值(|ζ|)均随电解质溶液浓度和压力的增加而减小;|ΔE|在不同电解质溶液中的顺序为:NaCl>MgCl2>KCl>KBr>Na2SO4>MgSO4;表面电荷密度的绝对值(|σd|)随电解质溶液浓度的增加而增加,随压力的增加而下降。The streaming potentials of nanofiltration （NF） membranes in electrolyte solutions are investigated. The effects of the concentration of electrolyte solutions, operating pressure, the type and valence of ions on the streaming potential （△E） of the NF membranes are studied. Secondly, measurements of the streaming potential gave a value for electrokinetic parameters such as the Zeta potential （ζ） of the NF membrane and the surface charge density （ σ^d ） at the exterior NF membrane surface. The effects of the concentration of electrolyte solutions and the operating pressure on the Zeta potential and surface charge density are studied too. The results show that both ｜ △E ｜ and ｜ ζ ｜ of the NF membrane decrease with the increase of the concentration of electrolyte solutions and the operational pressure; the order Of ｜ △E｜ is NaCl〉MgCl2〉KCl〉 KBr〉 Na2SO4〉MgSO4 ; ｜ σ^d ｜ of the NF membrane increases with the increase of the concentration of the electrolyte solutions, while decreases with the increase of the operation pressure. It is shown that measurements of the membrane potential are preferred for the study of the surface electrical capacities of NF membranes.

关 键 词：纳滤膜 荷电膜 流动电位 ZETA电位 表面电荷密度 

分 类 号：TQ028.8[化学工程]