Amorphous graphene - Transformer oil nanofluids with superior thermal and insulating properties

Nanofluids has emerged as a prominent and promising substitution of liquid dielectrics in industrial applications. Nevertheless, their sedimentation has been a consequential stumbling block for extensive and effective exploitation. Present work reports, stable, surfactant free and dilute homogeneous dispersion of a novel 2D dielectric nanomaterial: "Amorphous Graphene Sheets" (a-GS; with high ID/IG ratio), in transformer oil (TO) at lower nanofiller (0.0012-0.01 wt %) concentration. Nanofluids smartly address the much needed efficient thermal and electrical management with high resistivity and low loss compared to base oil. Persistent and high degrees of enhancement in the breakdown strength (40%) is observed. The electric double layer (EDL) development and prompted polarization (under electric stress), of the material leads to efficient charge trapping and de-detrapping in non-localized states. This phenomena uplifts the breakdown voltage and other electrical parameters than base TO. Lattice vibration of nanostructure along with EDL and cluster formation explains thermal transport phenomena at the nanoscale. Whereas confirmation of superior heat conduction by a-GS NEs were obtained by surface imaging and systematic study of spatial heat flow distribution. Hence the proposed hybrid nanofluid holds great promise for utilizing in the field of high voltage electrical insulation application. (C) 2018 Published by Elsevier Ltd.