Experimental and molecular dynamic insights on the thermophysical properties for MWCNT-Phosphonium based eutectic thermal media

•Deep Eutectic Solvent (DES) is synthesized by mixing a phosphonium salt with ethylene glycol at a molar ratio of 1:4.•Corresponding nanofluid was prepared by dispersing 0.02 wt% Multi-Walled Carbon Nanotube (MWCNT) having diameter 10–30.•Thermophysical properties such as density, viscosity, thermal conductivity, and specific heat of nanofluid were measured.•Molecular dynamics study were performed to compare and validate the results of thermal conductivity of nanofluid.