SURFACE MODIFICATION OF TITANIA NANOPARTICLES USING ULTRATHIN CERAMIC FILMS CERAMIC FILMS

Surface modification of titania nanoparticles was achieved by coating them with ultrathin alumina films using atomic layer deposition. The coating process was performed in a fluidised bed reactor at low pressure and under mechanical vibration. Films were deposited using self-limiting, sequential surface reactions of trimethylaluminium and water. The composition of alumina-coated particles was verified using IR spectroscopy. The deposited films had an average growth rate of 0.2 nm/coating cycle and were highly uniform and conformal as demonstrated by TEM and XPS. Deposited alumina films were amorphous as verified through XRD and HRTEM. The coating process did not promote particle sintering as validated via particle size and surface area analysis. 36 refs.