Evaluation and optimization of the thermal conductivity enhancement of a water-based GO nanosheets/Au NPs hybrid nanofluid: Box-Behnken design

Abstract

In this work, a decorated graphene oxide with gold nanoparticle (GO/Au NPs)/water hybrid nanofluid was prepared as an efficient hybrid nanofluid for thermal conductivity enhancement. The impact of essential parameters, including temperature, gold nanoparticle concentration and graphene oxide concentration on the enhancement of thermal conductivity was evaluated and optimized using the Box-Behnken design. Initially, the hybrid nanofluid was prepared by the interaction of graphene oxide nanosheets with gold nanoparticles in a water-based fluid using the ultrasonic-assisted method, and then it was characterized using different methods, including dynamic light scattering, transmission electron microscopy, zeta potential and X-ray diffraction. The Box-Behnken design was utilized to evaluate and optimize the influencing parameters on thermal conductivity enhancement. The optimized conditions using the Box Behnken design for thermal conductivity enhancement of GO/Au NPs hybrid nanofluid were: graphene oxide concentration; 1000 ppm, gold nanoparticle concentration; 62.5 ppm and a temperature of 41 °C. The thermal conductivity was enhanced by 48.1% under optimal conditions. According to the results, all three parameters of gold nanoparticle concentration, graphene oxide concentration, and temperature influence the final results.