Transmembrane redox reactions through polyaniline membrane doped with fullerene C60

Polyaniline (PANI)-C-60 membranes were chemically synthesized with fullerene C-60 content of 0.2, 0.5, 1, 2 and 3 mol% (relative to aniline fragment) respectively, and then systematically characterized with FTIR, field emission scanning electron microscopy (FESEM), XPS and electrochemical impedance spectroscopy (EIS). It is demonstrated that electron/ion coupled transport across PANI-C-60 membrane is possible in the presence of oxidizing agent at one side of the membrane and reducing agent at the other side. If 0.05 M acidic solution of FeCl3 was used as the oxidizing agent and 0.3 M ascorbic acid as the reducing agent, a typical value of transmembrane transport rate of redox equivalents was 3.1 x 10(-8) mol s(-1) cm(-2) with the membrane containing 0.5% C-60. This value was one order higher than that for HCl doped PANI membrane at identical conditions, which can be explained by superimposed C-60 doping and acid doping. The 0.5% content of C-60 is optimal and at higher content the rates of transmembrane redox transport decrease. (c) 2006 Elsevier B.V. All rights reserved.