Functionalization and exfoliation of graphite into mono layer graphene for improved heat dissipation

•To introduce in situ liquid-phase exfoliation and functionalization of graphene.•Mass-production of single layer graphene under microwave irradiation.•Novel nanofluid with excellent colloidal stability and thermo-physical properties.•Preparing water-based graphene nanofluids with low weight concentration.•Preparing a superior alternative coolant for using in ducts with backward-facing step.