Conductivity changes of dodecylbezensulfonic acid-doped polyaniline during pressure loading/unloading

Conductivity changes of polyaniline (PANi) doped with alkylbenzenesulfonic acid were investigated during pressure loading/unloading. PANi was chemically synthesized with ethylbenzenesulfonic acid (EBSA), octylbezenesulfonic acid (OBSA), and dodecylbenzenesulfonic acid (DBSA). Pellets were made for the comparison of chain length effects of PANi doped with alkylbenzenesulfonic acid on the conductivity change during pellet compression and expansion. PANi doped with DBSA exhibited the highest response to the pressure change. Relative amounts of DBSA to aniline (ANi) were adjusted to find out the optimal composition. It was revealed that the relative compositions of DBSA to PANi of pellets are similar (S/N ratio = 0.29-0.35) irrespective of feed ratios, but the conductivity change of pellets upon pressure loading/unloading becomes greater as the increase of relative amounts of DBSA to ANi in synthetic media. The variations of the conductivity change during repeated pressure loading/unloading were also compared. PANi pellets prepared from a solution containing [DBSA]/[ANi] = 2/1 retained more than 80% of the initial conductivity change value after 2000 cycles.