Automobile applications of optical thin films modified by nanotechnology

Photocatalytic properties of obliquely deposited TiO2 thin films with various shaped columns were investigated. The columnar films such as zigzag, cylinder and helix were prepared by dynamic oblique deposition (DOD) method. It was found that the optimum morphology for surface photocatalytic reaction has been obtained at the deposition angle (alpha) equals 70 degrees, where the photocatalytic activity is 2.5 times larger than that at (alpha) equals 0 degrees. In addition, effective surface area was estimated by Monte Carlo simulation and quantitative agreement was obtained between theoretical and experimental results. It was concluded that the enhanced surface photocatalytic properties of obliquely deposited TiO2 films can be explained in terms of effective changes in surface area originated from morphology modified by thin film nanotechnology.