Modeling Asymmetry of a Current–Voltage Curve of a Novel MF-4SC/PTMSP Bilayer Membrane

Abstract

A novel bilayer cation-exchange membrane—consisting of a thick layer of a pristine perfluorinated membrane MF-4SC (Russian equivalent of Nafion®-117) and a thinner layer (1 μm) of the membrane, on a base of glassy polymer of internal microporosity poly(1-trimethylsilyl-1-propyne) (PTMSP)—was prepared and characterized. Using the physicochemical characteristics of one-layer membranes MF-4SC and PTMSP in 0.05 M HCl and NaCl solutions, the asymmetric current–voltage curves (CVC) of the bilayer composite were described with good accuracy up to the overlimiting regime, based on the “fine-porous membrane” model. The MF-4SC/PTMSP bilayer composite has a significant asymmetry of CVC that is promising for using it in electromembrane devices, such as membrane detectors, sensors, and diodes.

Influence of Surface Forces on Membrane Separations

“…The aim of paper [14] is to establish and quantify the asymmetry of the current-voltage curve of a novel bilayer composite membrane based on a thick layer (219µm) of the cationexchange perfluorinated membrane, MF-4SC (the Russian equivalent of Nafion ® -117), and a thin (1µm) non-conducting layer of a glassy polymer of internal microporosity poly(1trimethylsilyl-1-propyne) (PTMSP) depending on the direction of the external electric field. The authors have theoretically shown that bilayer membranes with the highest difference in the modules of effective exchange capacities have the greatest asymmetry.…”