The influence of suspension composition and deposition mode on the electrophoretic deposition of TiO₂ nanoparticle agglomerates

The rate of cathodic electrophoretic deposition (EPD) of TiO₂ nanoparticle agglomerates and the density of the obtained films were measured as a function of the suspension composition, such as the particle concentration and the type of solvent. The difference in the dielectric constants of the solvents determines the ratio between ions and charged particles in the different suspensions and thus the deposition rate. We show that high quality mesoporous TiO₂ films can be produced by EPD with a well controlled thickness. In the mesoporous films we observe a high particle density close to the substrate while further apart the particle density is very low resulting in films with a very high porosity. We show that this density profile is independent of the specific solvent or particle concentration used in the suspension.