Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.
Plasma irradiation is one of the techniques to improve
surface wettability. This technique can be used to enhance heat
transfer of liquid-vapor phase change. For instance, evaporation
of water droplet can be enhanced by plasma irradiation.
Relation between plasma irradiation time and contact angle was
examined first for three metals and then the lifetime of water
drop on hot surface was measured changing the surface
wettability by plasma irradiation. The lifetime of water drop
decreased and the wetting limit temperature increased with the
increasing irradiation time of plasma. Hydrophilicity by plasma
irradiation is not a permanent effect but it will be useful for
enhancement of cooling of hot metal.