High temperature d.c. conductivity of sulfonic acid doped thermoreversible polyaniline gels

Abstract

Thermoreversible polyaniline gels in four different sulfonic acids 2,7-dinonylnapthalene-4-sulfonic acid (DNNSA), 2,7-dinonylnapthalene-4,5-disulfonic acid (DNNDSA), (±) camphor-10-sulfonic acid (CSA) and n-dodecyl-hydrogen sulfate (DHS) are prepared for different weight fractions of polyaniline (PANI). The high temperature d.c. conductivity of these gels is measured. Near the gel melting temperature a two/three order drop in d.c. conductivity is observed. Also metal like behaviour of conductivity with temperature is observed in some of these gels. Phase diagrams are drawn from these results and they almost coincide with those determined by DSC. The drop in conductivity is explained using a parameter defined as gel structure factor (F). © 2002 Elsevier Science B.V. All rights reserved.