Liquid-phase deposition of TiO2 on polystyrene latex particles functionalized by the adsorption of polyelectrolytes
The adsorption of polyelectrolyte layers on polystyrene latex particles was used as a method of surface functionalization for the nucleation and growth of a TiO2 shell on the lattices by liquid-phase deposition. Surface modification by adsorption of a single layer or a bilayer of polyelectrolytes was traced by zeta potential measurements. The TiO2 film formation is very sensitive to the nature of the adsorbed polyelectrolytes, and material deposition in an aqueous latex dispersion ranges from an exclusively homogeneous precipitation of TiO2 particles to a complete coating of the polymer surface with a smooth inorganic shell. An incomplete, patchy TiO2 deposition at the early stage of the coating process leads to a rapid growth of uneven shells, whereas uniform coverage of the substrate at the initial stage leads to the growth of smooth shells at a reduced deposition rate, suggesting that the shell growth rate and the extent of homogeneous precipitation is dependent on the interaction of the substrate with the deposition solution.