Current–voltage curves of a composite bipolar membrane in organic acid–water solutions

Abstract The current–voltage curves of a composite bipolar membrane (CBM) were measured experimentally for the various mole fractions of formic acid+water, acetic acid+water and propionic acid+water mixed solution systems. The experimental results showed that a CBM has the characteristics of a bipolar membrane. The current–voltage characteristics were analyzed using Mafe’s and Ramirez’s ion transport theory by applying the chemical reaction model in the intermediate region, and the theoretical calculations could well explain the experimental results. The increase in the mole fraction of the organic acid causes the increase of the ion concentration in the solution, and this effect enhances the water splitting. On the other hand, the increase in the mole fraction of the organic acid causes the decrease of the water concentration in the space charge region of the membrane also, and the effect lessens the water splitting. Based on the above two effects, it could be expected that with an increase in the mole fraction of the organic acid, the maximum local effective value of a CBM resistance decreases firstly, and then increases when the mole fraction of water becomes rather low. The results that we found in our experiments correspond to the above discussion.

[1]  Akihiko Tanioka,et al.  TRANSPORT OF IONS ACROSS BIPOLAR MEMBRANES. 2. MEMBRANE POTENTIAL AND PERMEABILITY COEFFICIENT RATIO IN CACL2 SOLUTIONS , 1997 .

[2]  H. Coster,et al.  A novel method for the characterisation of the double fixed charge (bipolar) membrane using impedance spectroscopy , 1995 .

[3]  José A. Manzanares,et al.  Effects of temperature and ion transport on water splitting in bipolar membranes , 1992 .

[4]  T. V. D. Boomgaard,et al.  Current-voltage curve of a bipolar membrane at high current density , 1996 .

[5]  A. Higuchi,et al.  Membrane potential and ion transport in inhomogeneous ion-exchange membranes , 1989 .

[6]  Salvador Mafé,et al.  A SIMPLE MODEL FOR AC IMPEDANCE SPECTRA IN BIPOLAR MEMBRANES , 1996 .

[7]  Akihiko Tanioka,et al.  Effect of polymer materials on membrane potential, rectification and water splitting in bipolar membranes , 1996 .

[8]  P. Searson,et al.  The Anodic Dissolution of Silicon in HF Solutions , 1990 .

[9]  J. Manzanares,et al.  Membrane potential of bipolar membranes , 1996 .

[10]  Akihiko Tanioka,et al.  CURRENT-VOLTAGE CURVES OF COMPOSITE BIPOLAR MEMBRANE IN ALCOHOL-WATER SOLUTIONS , 1998 .

[11]  H. Strathmann,et al.  Limiting current density and water dissociation in bipolar membranes , 1997 .

[12]  Akihiko Tanioka,et al.  Effect of interface structure and amino groups on water splitting and rectification effects in bipolar membranes , 1997 .

[13]  H. S. Harned,et al.  The Dissociation Constant of Acetic Acid from 0 to 60° Centigrade1 , 1933 .

[14]  G. Pourcelly,et al.  Co-ion leakage through bipolar membranes Influence on I-V responses and water-splitting efficiency , 1994 .

[15]  Yutaka Yokoyama,et al.  Membrane potential of bipolar membranes prepared by plasma-induced grafted polymerization on porous polyolefin , 1997 .

[16]  Mitsuru Higa,et al.  Transport of Ions across Bipolar Membranes. 1. Theoretical and Experimental Examination of the Membrane Potential of KCl Solutions , 1995 .

[17]  H. S. Harned,et al.  The Dissociation Constant of Propionic Acid from 0 to 60 , 1933 .

[18]  P. Ramirez,et al.  Electrochemical characterization of polymer ion-exchange bipolar membranes , 1997 .

[19]  E. Caldin.  Fast reactions in solution , 1964 .

[20]  Salvador Mafé,et al.  Bipolar membranes under forward and reverse bias conditions. Theory vs. experiment , 1994 .

[21]  H. S. Harned,et al.  The Ionization Constant of Formic Acid from 0 to 60°1 , 1934 .

[22]  H. Coster,et al.  AC impedance of the bipolar membrane at low and high frequencies , 1995 .

[23]  N. Gnusin,et al.  Dissociation of Water Molecules in Systems with Ion-exchange Membranes , 1988 .

[24]  R. Simons,et al.  Electric field effects on proton transfer between ionizable groups and water in ion exchange membranes , 1984 .

[25]  Rectification by a Double Membrane , 1965 .

[26]  H. Strathmann,et al.  Current‐voltage curves of bipolar membranes , 1992 .

[27]  L. Onsager.  Deviations from Ohm's Law in Weak Electrolytes , 1934 .