Density Analysis of rGO–Nanodiamond Hybrid Nanofluids Based on Water, Ethylene Glycol and their Mixtures

This work examines the density of a mixture of reduced graphene oxide–nanodiamond (rGO–ND) nanoparticles dispersed in five different nanofluids. The base fluids considered in this study are water, ethylene glycol, 80:20% W+EG, 60:40% W+EG, and 40:60% W+EG mixtures. In order to prepare the stable hybrid nanofluids, the graphene oxide-nanodiamond hybrid nanoparticles were dispersed in the base fluids. Measurements were performed under different volume loadings (0 < < 1.0%), and different temperatures (293 K < T < 333 K). An increase in density was observed with increasing volume loadings and temperatures. A maximum density enhancement of 1.1314% was observed for the case of water-based hybrid nanofluids compared to the other nanofluids. Based on the obtained data, non-linear regression equations were proposed.