Aqueous phase deposition of Fe3O4 on the polyelectrolyte multilayered films prepared via layer-by-layer assembly

Fe3O4 coatings were successfully fabricated on polyelectrolyte multilayered films by aqueous solution process using Pd catalyst nanoparticles. Fe3O4 particles were selectively deposited on Pd catalysts which were adsorbed to the –NH2-terminated surface of polyelectrolytes, in an aqueous solution containing iron nitrate and dimethylamine-borane. Pd colloid catalyst particles were adhered to the amino group of the outmost layer of polyelectrolyte multilayered films mainly by electrostatic interaction. Crystalline Fe3O4 particulate films were then deposited on the NH2-groups region by the effect of metal Pd catalyst. In addition, the surface charge density played an important role for adsorption behavior of Pd catalyst particles and Fe3O4 film formation.