Self-assembly and characterization of polyaniline and sulfonated polystyrene multilayer-coated colloidal particles and hollow shells

Conductive core-shell particles were prepared by the deposition of polyaniline (PANI) and poly(sodium 4-styrenesulfonate) (PSS) multilayers onto polystyrene (PS) colloidal particles via the alternate electrostatic layer-by-layer (LbL) assembly technique. PSS was used as a polymeric counterion for multilayer formation as well as a stabilizer and codopant for PANI. Electrophoresis, FT-IR spectroscopy, and transmission electron microscopy (TEM) confirmed the regular growth of PSS/PANI multilayers on PS colloidal particles. It was found that the PSS/PANI-coated particle is oxidatively more stable due to stabilization of the partially oxidized emeraldine salt by PSS. The conductivity of (PSS/PANI)(5)-coated PS particles was 0.003 S/cm and increased to 0.1 S/cm after additional dopant exposure with HCl vapor. Furthermore, hollow shells made up of PSS/PANI layers were produced by dissolution of the PS core from PSS/PANI-coated particles. Cyclic voltammetry (CV) showed that PSS/PANI multilayers maintained their oxidative stability and electrochemical properties after removal of the core.