Elaboration of thermophysical performance enhancement mechanism of functionalized boron nitride/graphite hybrid nanofluids

This study mainly investigated the physicochemical characteristics of ethylene glycol/ water (EG/W) based hydroxyl-functionalized boron nitride (BN-OH) and graphite (G) hybrid nanofluids. A novel simple and efficient annealing method was proposed to have hexagonal boron nitride (h-BN) nanoparticles func-tionalized to improve the synergistic role between hybrid G/BN-OH nanoparticles. Meanwhile, the dis-persion stability, thermal stability, and rheological behavior of diverse nanofluids (h-BN, BN-OH, G, G/ BN and G/BH-OH) were comprehensively evaluated. The results showed that the G/BN-OH hybrid nanofluids demonstrate both better dispersion stability and thermal stability, as well as a lower increase in viscosity. In addition, the thermal conductivity of G/BN-OH hybrid nanofluids was increased by up to 18.05% with a concentration of 0.2 wt% when compared to the base fluid. Ultimately, the complicated theoretical mechanism of thermophysical performance augment for G/BH-OH hybrid nanofluids was reli-ably presented. The enhanced thermal conductivity of nanofluids may be attributed to the formation of adsorption layers and the synergistic effect of the thermal conductivity network.(c) 2023 The Society of Powder Technology Japan. Published by Elsevier BV and The Society of Powder Technology Japan. All rights reserved.

Automated summary

This study investigates the physicochemical characteristics of ethylene glycol/water-based hydroxyl-functionalized boron nitride and graphite hybrid nanofluids. A novel annealing method is proposed to improve the synergy between hybrid graphite/boron nitride nanoparticles. The dispersion stability, thermal stability, and rheological behavior of various nanofluids are evaluated, and it is found that the G/BN-OH hybrid nanofluids show better dispersion stability, thermal stability, and lower increase in viscosity. The thermal conductivity of G/BN-OH nanofluids is increased by up to 18.05% compared to the base fluid.