Thermoreversible gels of acid doped polyaniline: Electrical switching based on network transitions

Thermoreversible gelation of polyaniline (PANI) dissolved in dodecyl benzene sulphonic acid (DBSA) is here demonstrated for systems containing ca. 7-16 wt % of PANI. Below the gel melting temperature such materials show elastic behavior, i.e. recovery of dimensions after stress release, and frequency independent dynamic moduli. Above the gel melting temperature, the materials are viscous fluids showing frequency dependent dynamic moduli. The gel melting temperature depends on the weight fraction of PANI dissolved in DBSA. It is shown that thermoreversible gelation allows temperature controlled reversible switching of electrical conductivity.