A Simple Approach Towards Synthesis of Nanofluids Containing Octahedral Copper Nanoparticles

Abstract

Nanofluids are a new kind of heat transfer fluids engineered by suspending nanoparticles with higher thermal conductivity in conventional heat transfer fluids with a motive of achieving enhanced heat transfer properties. Copper nanofluids have been synthesized by a simple and cost effective way by reducing copper nitrate using ascorbic acid. The employed solution phase synthesis utilizes a mixture of ethylene glycol and water as base fluid. Octahedral copper nanoparticles were formed when polyvinylpyrrolidone was added as a stabilizing agent. The synthesized nanofluids have been characterized by XRD, microscopic and spectroscopic techniques. The sedimentation measurements showed that the as synthesized nanofluid had a stability of more than 6 weeks. Rheological measurements revealed that the nanofluid is Newtonian in nature in the temperature range of 20 °C to 50 °C. The thermal conductivity of the copper nanofluid has been found to be 1.774 W m–1 K–1 for the particle weight fraction of 0.167%. The proposed single step method is facile, mild, low cost and extendible technique for the synthesis of nanofluids with enhanced thermal conductivity.