Rapid synthesis of MgO nanoparticles & their utilization for formulation of a propylene glycol based nanofluid with superior transport properties

Experiments were performed on the synthesis of magnesium oxide nanoparticles (30-40 nm), followed by their dispersion in propylene glycol to prepare stable MgO-propylene glycol nanofluids through extensive probe ultrasonication for 25 h. The influence of MgO nanoparticle concentration (0-2 vol%) and temperature on viscosity and thermal conductivity of MgO-propylene glycol nanofluids was investigated. While the relative viscosity of the nanofluid decreased with nanoparticle concentration to a temperature of 30 degrees C, the relative viscosity-nanoparticle concentration exhibited a minimum at 1 vol% in the temperature range of 35-60 degrees C. The enhancement in thermal conductivity of nanofluids increased linearly with nanoparticle concentration and was found to be independent of temperature, with an average enhancement of similar to 20% for 2 vol% MgO-propylene glycol nanofluid. Our results show that the thermal conductivity enhancement in MgO-propylene glycol can be attributed to both interfacial layering and Brownian motion.