(156c) Water Resistance of Nano-Particles Water Repellent

It is known that surface roughness emphasizes the influence of hydrophobic or hydrophilic natures of the surface. When nano-particles with hydrophobic surface are adhered on a clear glass plate to produce nano-scale roughness, the glass plate shows super hydrophobic nature with the transparency maintained. The hydrophobic nano-particles, whose particle size is much smaller than the wavelength of visible light, were dispersed in alcohol solution and the nano-particle suspension sprayed on a glass plate. After drying, nano-scale roughness was produced on the glass plate surface, and the roughness and the thickness of the surface are observed by Scanning Probe Microscope. The contact angle of water droplet on the glass plate shows 160 degree or more and the glass plate is almost nearly transparent to visible light. The water resisting property of the plate can be enhanced by adding water repellent agent in the alcohol solution. Our water repellent using hydrophobic nano-particles is highly effective in preventing water droplet on side-view mirror or camera lens in improving visibility on rainy days.