Secondary doping in elastomeric polyaniline blends

We have succeeded in producing, from solution, conductive rubbery blends of poly(styrene-ethylene/butylene-styrene) triblock copolymer and polyaniline. Elastomeric free-standing films were obtained by casting pqlyaniline doped with camphor sulfonic acid. These blends were studied by UV-Vis-NIR spectroscopy, X-rays diffraction and conductivity measurements. Remarkably, they possess extremely low percolation threshold reaching electrical conductivity up to 5S/cm for blends containing only about 5% (wt) of the conducting polymer. The low energy of the delocalized polaronic band and the crystalline diffraction peaks presented by such material are consistent with secondary doping effects which leads to the high conductivity values obtained due to an extended conformational formation of the doped polyaniline backbone. The choice of an appropriate solvent, co-solvent and counter ion system is extremely important for producing blends of polyaniline with enhanced properties.