Dependence of thermal diffusivity on nanoparticle shape deduced through thermal lens technique taking ZnO nanoparticles and nanorods as inclusions in homogeneous dye solution

Abstract

We are presenting our results of comparison of thermal diffusion behavior of composite media of nanoparticles and nanorods of ZnO in a homogeneous solution of fluorescein dye, done using the dual beam, pump-probe thermal lens technique. It was observed that both nanorods and nanoparticles can be used to control the thermal diffusivity of the composite fluid by changing the relative volume fractions. It was also observed that there is an optimum value for this volume fraction in the two cases considered. We have also explained this behavior using theoretical approach taking into account the Unit cell model, Brownian motion and the near field effects. We expect that this work will enhance the understanding of the influence of particle size, shape and the thermal properties of this novel composite which can widely find application in thermoelectric coolers, high performance thermal transfer liquids and in random lasing.