动电法研究磺化聚醚砜纳滤膜界面电现象  

Study on Interfacial Electrical Phenomena of Sulfonated Polyethersulfone Nanofiltration Membrane by Electrokinetic Method

作　　者：马准[1] 高学理[1] 汪锰[1] 王铎[1] 高从堦[1] 

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

出　　处：《分析化学》2010年第4期547-550,共4页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金(Nos.20636050;20706050);国家重点基础研究发展计划(No.2009CB623402)资助

摘　　要：采用动电法对表面具有功能基团解离的磺化聚醚砜纳滤膜(NTR-7450)界面电现象进行探索。其中,在Zeta电位测试过程中引入相关措施,例如采用电化学工作站测定体系总电导(膜体电导、膜表面电导和电解质溶液电导)和变化流道高度等,以便获得更为真实的Zeta电位,进而根据Gouy-Chapman双电层模型系统地考察了离子强度、阴离子种类(KCl,K2SO4和K3PO4)对膜表面荷电性能的影响。实验结果表明,在较低浓度(0.1～0.5mmol/L)电解质溶液中,磺酸基的解离是NTR-7450纳滤膜荷电的主要原因;而在较高浓度下(1.0～10mmol/L),NTR-7450纳滤膜荷电则是由特性吸附引起,并且膜体积电荷密度与电解质溶液浓度之间符合Freundlich吸附等温式:在KCl,K2SO4和K3PO4溶液中分别为:ln|X|(mmol/L)=2.3337+0.772lnC(mmol/L),ln|X|(mmol/L)=3.584+1.119lnC(mmol/L)和ln|X|(mmol/L)=2.988+1.067lnC(mmol/L)。Experimental investigations on interfacial electrical phenomena of NTR-7450 nanofiltration membrane that had dissociated functional groups were performed by electrokinetic method.To obtain the accurate zeta potential,the corresponding measures were taken,for examples,the determination of the total conductance of the system including the surface conductance,the membrane body conductance and the electrolyte solution conductance by means of the electrochemical work station and alteration of the channel heights. Furthermore,the surface charge density could be estimated by the Gouy-Chapmann double-electric layers theory and evaluated the influence of the ionic strength and the type of ions（KCl,K 2 SO4 and K3 PO4）on the membrane surface charge.From the preliminary experimental results,the mechanism of charge formation of NTR-7450 membrane was confirmed.That is,its charge formation was attributed to the dissociation of the functional group at relatively low concentration（0.1-0.5 mol/L）.However,at the relatively high concentration,the charge formation of NTR-7450 nanofiltration membrane should be ascribed to the specific adsorption.The relationship between the volume charge densities,X,and the feed solution concentration,C,agreed well with Freundlich absorption isotherms.That was,for KCl solution：ln｜X｜（mmol/L）=2.3337＋ 0.772lnC（mmol/L）,for K 2 SO4 solution：ln｜X｜（mmol/L）=3.584＋1.119lnC（mmol/L）;for K 3 PO4 solution：ln｜X｜（mmol/L）=2.988＋1.067lnC（mmol/L）.

关 键 词：聚醚砜 纳滤膜 界面电现象 动电法 电荷密度 

分 类 号：TB383.2[一般工业技术—材料科学与工程]