Alteration of Thermal Conductivity and Viscosity of Liquid by Dispersing Ultra-Fine Particles

Dispersion of Al₂O₃, SiO₂ and TiO₂ Ultra-Fine Particles

Abstract

How much the thermal conductivity of a liquid can be altered by dispersing a small amount of ultra-fine particles into it has been studied. Fine powders of Al₂O₃, SiO₂ and TiO₂ were used as the ultra-fine particles, and water was selected as the base liquid. Three dispersed systems were made by applying the technique of electrostatic repulsion. For the systems of water-Al₂O₃ and water-TiO₂, effective thermal conductivities were seen to increase much more as the particle concentration was increased, but that of water-SiO₂ system almost never increased. Viscosities of their dispersed systems were also measured, and the characteristics were made clear.