Current–Voltage Characteristics and Solvent Dissociation of Bipolar Membranes in Organic Solvents

In this work, the chronopotentiometric responses, pH changes, and current–voltage (I–V) characteristics of bipolar membrane (BPM)/LiCl–organic solvent systems were measured and compared with those of the BPM/LiCl–water system. Monohydric alcohols, polyhydric alcohols, and amides were used as organic solvents. The chronopotentiograms and pH changes supported that the organic solvents can dissociate into cations and anions at the BPM interface. It is found that amides cannot dissociate easily at the BPM compared with alcohols. The I–V characteristics showed that both the viscosity and acid–base property of organic solvents substantially influences the dissociation behaviors in addition to the autoprotolysis constant and relative permittivity of the solvents.