Transformer Oil Nanofluids by Two Dimensional hexagonal Boron Nitride Nanofillers

This paper explores the fascinating properties of two-dimensional (2D) nanofillers based transformer oil (TO) nanofluids. Nanofluids of 2D hexagonal boron nitride (h-BN) nanosheets in TO demonstrate stable dispersion with improved dielectric breakdown strength and superior thermo physical properties like thermal conductivity, viscosity and stability. An appreciable augmentation in AC breakdown voltage (BDV) is observed compared to the state-of-the-art boron nitride (BN) particles. This enhancement in BDV is elucidated by the role of the greater surface area of Maxwell-Garnet ‘oil-sheet’ interfacial region of the 2D morphology in charge trapping perspective. The faster rate of heating and cooling along with noteworthy enhancement in thermal conductivity is due to the interfacial heat transfer via 2D nanoadditives prompting good phonon transport which agrees with Maxwell's forecasts. Addition of 2D nanofiller at diluted concentration exhibits better stability and high thermal efficiency compared to its particle counterpart. Hence, 2D nanofillers are better choices for next generation transformer oil nanofluids, due to their high surface area, lower filler fraction and better stability.