Evaluation of Thermal Conductivity, Stability and Viscosity of Two Dimensional Hexagonal Boron Nitride Nanofluids

Abstract

Being a new generation of heat transfer fluids, nanofluids have attracted research community due to the irremarkable thermo-physical properties. This paper presents the experimental investigation on the thermal conductivity (from 25 °C to 50 °C), stability, and viscosity (at ambient conditions) analysis of two-dimensional hexagonal boron it ride (2D, h-BN) nanofluids using ethylene glycol as base fluid. Stable nanofluids were prepared using the two-step method at various volume concentration of nanomaterial and dispersant. The stability and particle size distribution is determined using dynamic light scattering (DLS) and electro phoretic light scattering (ELS) techniques, respectively. The h-BN nanofluids showed anomalous thermal conductivity enhancement of about 30% without dispersant at 50 °C whereas maximum reduction in viscosity is observed to be about 7.4% at ambient temperature for h-BN nanofluids with dispersant. This approach could be further extended to investigate the role of surfactants on rheology of nano fluids as a convenient and economical strategy for commercial use.