Electrical and Thermal Conductivities of Dilute Nanofluids-Experimental Determination and Parametric Studies

Stable suspensions of nanoparticles in liquids show remarkable modifications in transport properties even at low particle concentrations. This paper presents experimental determination of the effective electrical and thermal conductivities of dilute nanoparticle suspensions, in an attempt to understand the influence of the particle volume fraction and temperature on their values. Optical measurement of the refractive index and absorbance of the suspensions have been utilized to obtain the electrical conductivity values, and the thermal conductivity has been measured using transient measurement method. Experiments were conducted on nanoparticle suspensions containing Alumina (Al2O3), Titanium dioxide (TiO2) and Copper oxide (CuO) dispersed in water, using ultrasonic agitation, with the volume concentration ranging from 0.0015% to 0.005%. Dependence of the transport properties of the suspensions on temperature, and the sonication time in preparing the nanofluids was determined.