Temperature-dependent thermal conductivity of nanorod-based nanofluids

In this work, the temperature dependence of thermal conductivity enhancement in nanofluids containing Bi2Te3 nanorods has been studied. The Bi2Te3 nanorods of average diameter 20nm and length 170nm are synthesized using the sonochemical technique. The 3ω-wire method has been developed to measure the thermal conductivity of nanofluids. The thermal conductivity enhancement in the nanorods-in-FC72 and the nanorods-in-oil nanofluids has been experimentally found to decrease with increasing temperature, in contrast to the trend observed in nanofluids containing spherical nanoparticles. The contrary trend is attributable mainly to the particle aspect ratio.