Paper SS1-WeA3
Structure-Property Relationships of Water Interfaces 200^o Beyond the Boiling Point

Wednesday, November 11, 2009, 2:40 pm, Room M

In cooling technologies that utilize the latent heat of vaporization (e.g. pool boiling and spray cooling), knowledge of the critical heat flux is “critical.” Beyond the critical heat flux, a continuous vapor layer forms at the solid-liquid interface that impedes heat transfer. The formation of this chaotic, thermally-resistive vapor layer” is well known. However, our recent research has demonstrated that a new, unique, and stable water interface is formed beyond the critical heat flux for surface temperatures 100+ degrees above the boiling point. At this point, film boiling stops, forming a smooth, highly light reflective, high surface energy water interface that further impedes heat transfer. We present our efforts in correlating the thermal, mechanical, and structural properties of this unique water interface using high-speed imaging, Raman spectroscopy, and numerical modeling. Critical heat flux data as a function of vapor pressure is also presented for water boiling on patterned surfaces of carbon nanotubes and nanowire whisker arrays.