Redox reactions and charge transport through polyaniline membranes

Abstract

The objective of this project is to investigate new trans-membrane redox reactions through PANI membranes that involve electronic/ionic permeability in the membrane. PANI films doped with d,l-camphor sulfonic acid (PANI-CSA films) were synthesized and characterized by different instrumental methods. The films remained active at neutral pH, which is different from the HCl-doped PANI films that lost electroactivity at the similar conditions. A new type of trans-membrane redox reaction was designed by placing an oxidizing agent at one side of PANI-CSA membrane and a reducing agent at the other side. Such a process can be realized if both aqueous solutions have pH>3.0, which is distinct from the situation when PANI-HCl membrane is employed. A novel kind of redox sensor via the measurement of trans-membrane potential was then developed. Moreover, redox reactions of PANI powders/films with dissolved oxygen were also investigated with the aim of producing H2O2, a useful chemical reagent.