Copper and copper compounds as coatings on polystyrene particles and as hollow spheres

Submicron-sized anionic polystyrene latices have been coated with uniform layers of copper compounds by aging dispersions of the polymer colloid in the presence of aqueous solutions of Cu(NO3)(2), urea, and poly(N-vinylpyrrolidone) at 85 degrees C. The thickness and morphology of the deposited layers can be altered by suitable adjustment of the reactant concentrations and the aging time. Hollow colloidal spheres of metallic copper and copper oxide were obtained by calcination of the coated polystyrene latices at elevated temperatures in nitrogen and air, respectively.