| A "template" synthesis route was used for preparing electronically conductive polymers. This "template" approach entails synthesis of a material within the pores of a microporous membrane. Microtubules of polyaniline (PANi) were obtained using this approach. These template-synthesized polyaniline tubules showed enhancements in electronic conductivities over conventional forms of analogous polymers. The origin for this enhancement in conductivity was studied using a host of techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), and polarized infrared absorption spectroscopy (PIRAS). TEM was used to monitor the growth of PANi within the pores. For short polymerization times, a thin skin of polymer lines the pore walls. With increase in polymerization time, the polymer grows in thickness. PIRAS data show that the polymer deposited directly on the pore wall is highly-ordered relative to subsequently deposited polymer. This ordering of the polymer chains is responsible for the enhancement in conductivity. PIRAS was also used to show that the polymer chains are preferentially aligned perpendicular to the tubule axis.;Thin films of polypyrrole were also synthesized using non-porous polycarbonate as a support membrane. Chemical treatment of these polypyrrole films with aqueous base yields a partially-doped form of the polymer. We have found that this partially-doped form of polypyrrole can show extraordinarily high gas-transport selectivity for O;Finally, the template approach was used to fabricate an array of carbon nanotubes using a polyacrylonitrile (PAN) precursor route. These nanotubes were observed using SEM.;Based on this template route, capped versions of polypyrrole tubules (i.e. microcapsules) were prepared. These hollow microcapsules are arranged in a high-density array in which the individual capsules protrude from a surface like the bristles of a brush. Procedures were developed for filling these microcapsules with high concentrations of enzymes. The enzyme-loaded microcapsule arrays function as enzymatic bioreactors in both aqueous solution and organic solvents. |
