Tj. Chou et A. Tanioka, CURRENT-VOLTAGE CURVES OF COMPOSITE BIPOLAR MEMBRANE IN ALCOHOL-WATERSOLUTIONS, JOURNAL OF PHYSICAL CHEMISTRY B, 102(40), 1998, pp. 7866-7870
The current-voltage curves of a composite bipolar membrane (CBM) were
experimentally measured for the various mole fractions of methanol-wat
er, ethanol-water, and n-propanol-water mixed solution systems. In eac
h solution system, 0.1 mol/L LiCl was used as the electrolyte. The exp
erimental results showed that a CBM has the characteristics of a bipol
ar membrane. The current-voltage characteristics were analyzed using M
afe and Ramirez's ion transport theory by applying the chemical reacti
on model in the intermediate region, and the theoretical calculations
were able to well explain the experimental results. The current-voltag
e curves show that the maximum local effective value of a CBM resistan
ce will increase with an increase in the mole fraction of alcohol. Thi
s phenomenon is due to the fact that the dissociative ability of an al
cohol is much weaker than that of water; thus, the current is mainly i
nduced by the water splitting. However, methanol splitting was observe
d in the case of the LiCl-methanol solution because of its somewhat la
rge autoprotolysis constant.