Crystallization driven formation of conducting polymer networks in polymer blends

Electrically conducting networks based on polyaniline-camphorsulfonic acid (PANI-HCSA), blended with crystalline and amorphous polyamides (nylon 6 and Selar), and poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT-PSS), blended with poly(ethylene oxide) (PEO) and poly(vinyl alcohol) (PVA), were prepared from solution. These blends exhibited a conductivity that rises smoothly and rapidly from the insulating state with increasing conducting polymer content. When the conducting polymer salts are blended with insulating crystalline hosts, they show a more rapid increase in conductivity relative to blends prepared using amorphous hosts. This faster rise in electrical conduction stems from the presence of more developed conductive pathways in the crystalline host blends due primarily to the crystallization driven Exclusion of the conducting polymer into the interspherultic region as seen by transmission electron microscopy (TEM). In the PANI-HCSA/nylon 6 blends conductivities of 1 S/cm are found at 10% loading (wt/wt), approximately 10 times higher than the conductivity observed using the amorphous Selar host. Similar conductivity differences are seen in comparing crystalline and amorphous hosts with PEDOT-PSS, though the magnitudes of the conductivities are lower.