1-1型单组分盐溶液中荷电膜膜电位的研究

1. (清华大学化工系 北京 100084)

• 投稿日期:2008-06-24 修回日期:2008-09-25 发布日期:2009-05-14
• 通讯作者: 王晓琳

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

Shang, Weijuan Wang, Hongli Tu, Conghui Ding, Ning Wang, Xiaolin*

1. (Department of Chemical Engineering, Tsinghua University, Beijing 100084)

• Received:2008-06-24 Revised:2008-09-25 Published:2009-05-14
• Contact: Wang, Xiaolin

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 KCl 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 concentration 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.