Preparation of superhydrophobic boehmite and anatase nanocomposite coating films

Developing a surface with water-repelling and self-cleaning ability has attracted much interest in nano-technology. We prepared superhydrophobic films in this study using a mixture of small anatase particles and large boehmite particles. Additionally, a N-2 automated adsorption apparatus, atomic force microscopy and contact angle meter were employed to examine the effects of the added boehmite and anatase to the boehmite ratio on the roughness, micropore ratio and contact angle of the hydrophobic films. As boehmite addition increased from 0 to 8 wt.%, the average roughness increased up to 30 nm, which resulted in the water contact angles increasing from 105 degrees to 155 degrees. The hardness of the films increased from 6B to 2H. The addition of a proper amount of small anatase particles into the large boehmite particles could lead to increasing the micropore ratio in the films, which would enhance the contact angle. (C) 2006 Elsevier Ltd. All rights reserved.