1-1型单组分盐溶液中荷电膜膜电位的研究  

Membrane Potential of Charged Porous Membranes in Single 1-1 Electrolyte Solutions

作　　者：尚伟娟[1] 王弘历[1] 涂丛慧[1] 丁宁[1] 王晓琳[1] 

机构地区：[1]清华大学化工系,北京100084

出　　处：《化学学报》2009年第9期969-973,共5页Acta Chimica Sinica

基　　金：国家973计划(No.2009CB623404)资助项目

摘　　要：根据固定电荷模型和非线性最小二乘法,研究膜体积电荷密度为定值和其大小随电解质主体溶液浓度呈指数变化的两种初始条件下,五种纳滤膜(NTR7450,ESNA1,ESNA1-LF,LES90和UTC60)在不同浓度的氯化钠和氯化钾溶液中的膜电位,获得膜体积电荷密度与电解质主体溶液浓度的关系.结果表明,当体积电荷密度随浓度呈指数变化时,拟合的膜电位与实验结果更接近,得到的固定电荷密度更精确.膜电位的大小与膜两侧电解质溶液浓度的比值相关.在较高浓度时,膜电位的值还与扩散系数相关;其中阴阳离子的扩散系数之比大于1.0是膜电位反号的标志.在中间浓度时,膜电位随电解质主体溶液浓度近似呈线性变化.According to the Teorell Meyer Sievers （TMS） model and the nonlinear least squares procedure, volumetric charge densities of five commercial nanofiltration membranes （NTR 7450, ESNA 1, ESNA 1-LF, LES 90 and UTC 60） can be obtained by measuring the membrane potentials （MP） of NaCl and KCI solutions across these membranes. The simulation was calculated under two kinds of initial conditions： a uniform and an exponential variation of volumetric charge density with the bulk electrolyte concentration. The results suggested that the exponential variation of volumetric charge density with the bulk electrolyte concentration is more favorable to describe the membrane potential and to evaluate the induced fixed charge density. MP was dependent on the concentration ratio of electrolyte solutions of each side. In the high con- centration region, MP also relied on ionic diffusion coefficient, and its value would be reversed if the diffusion coefficient ratio of co-ion to counter-ion was larger than 1.0. While in the intermediate concentration region, MP as a function of electrolyte concentration was almost linear.

关 键 词：固定电荷模型 非线性最小二乘法 荷电膜 膜电位 固定电荷密度 

分 类 号：O621.2[理学—有机化学]