Sterically stabilized polypyrrole-palladium nanocomposite particles synthesized by aqueous chemical oxidative dispersion polymerization

Aqueous chemical oxidative dispersion polymerizations of pyrrole using PdCl2 oxidant were conducted using water-soluble polymeric colloidal stabilizers in order to synthesize polypyrrole-palladium (PPy-Pd) nanocomposite particles in one step. PPy-Pd nanocomposite particles with number average diameters of approximately 30 nm were successfully obtained as colloidally stable aqueous dispersions, which were stable at least for 7 months, using poly(4-lithium styrene sulfonic acid) colloidal stabilizer. The resulting nanocomposite particles were extensively characterized with respect to particle size, size distribution, colloidal stability, nanomorphology, surface/bulk chemical compositions, and conductivity. X-ray photoelectron spectroscopy indicated the existence of poly(styrene sulfonic acid) colloidal stabilizer on the surface of the nanocomposite particles. Transmission electron microscopy studies confirmed that nanometer-sized Pd nanoparticles were distributed in the PPy matrix.