Contact Angle and Boiling Heat Transfer of TiO_2-sputtered Surface

Abstract

We have developed a superhydrophilic metallic surface by sputtering process. By exposing the surface to ultraviolet ray, the contact angle decreases to zero under UV illumination. We applied this surface to enhancement of boiling heat transfer. Heat transfer characteristic of pool boiling has been investigated using TiO_2-sputtered copper surface. Experiments have been conducted both for TiO_2-coated and non-coated surfaces and it is found that the maximum heat flux of TiO_2-coated surface is almost double to non-coated surface and temperature at the minimum heat flux of TiO_2-coated surface is much higher than of non-coated one.