Photothermal measurement of the thermal conductivity of supercooled water

Abstract

Thermal diffusivity measurements of supercooled water have been performed between + 40 °C and - 23 °C, using both optically induced periodic and pulsed heat source in two separate experiments. The resulting temperature field is analysed by monitoring the deflection of a He-Ne laser beam. The thermal conductivity, λ, as deduced from the experiments, decreases continuously with decreasing temperature. The analysis of λ is also discussed both in terms of the classical expression and in terms of a critical law. The influence of the hydrogen bond network structure is discussed, as well. It is verified that the classical relations between λ and the sound velocity, c, are respected, and consequently that the hydrogen bond network structure has the same influence over both λ and c.