▎ 摘　　要

NOVELTY - A functionalized graphene nanofluid is produced by preparing exfoliated graphene oxide by treating graphite with acid in presence of potassium permanganate; reacting the exfoliated graphene oxide with saffron in a reaction medium comprising ammonium solution to obtain functionalized graphene; ultrasonicating the functionalized graphene; and dispersing the ultrasonicated functionalized graphene in distilled water to produce the functionalized graphene nanofluid. USE - Production of functionalized graphene nanofluid used as coolant in heat transfer system (all claimed). ADVANTAGE - The method produces functionalized graphene nanofluid that uses water as base fluid for dispersion of functionalized graphene while omitting the use of surfactant, stabilizing agent or dispersing agent. The functionalized graphene nanofluid exhibits satisfactory level of thermo physical, rheological and heat transfer properties.