METAL SURFACE WETTABILITY MANIPULATION BY NANOPARTICLE DEPOSITION DURING NANOFLUID BOILING

摘要

Surface wettability of materials is important in heat transfer and thermal processes at micro-scale. This paper presents the manipulation of metal surface wettability by nanofluid boiling nanoparticle deposition. As confirmed by microscopy, particles can be deposited on metal surfaces by boiling in nanoparticle suspension, which significantly enhanced the surface wettabiliy relative to that of its original condition. The change in wettability is coupled to boiling conditions, such as nanoparticle concentration, heat flux, boiling duration, substrate roughness and so on. It has been observed that the higher the concentration of nanoparticles in the liquid during the boiling deposition process, the more pronounced the impact on wetting. Hence, surface wettability can be manipulated by controlling the nanoparticle concentration during the nanofluid boiling nanoparticle deposition (NBND) process. Such method can potentially be applied to enhance the heat transfer performance in thermal devices.