▎ 摘　　要

NOVELTY - A Janus graphene nanosheet surfactant comprises two-dimensional graphene oxide comprising a face (f1) and a face (f2). The face (f1) and/or face (f2) comprises oxygen-rich functional group(s). A hydrophobic group is linked to face (f1) using the oxygen-rich functional group. Face (f2) comprises hydrophilic group. The Janus graphene nanosheet is amphiphilic surfactant. USE - Janus graphene nanosheet surfactant is used in emulsion and nano-fluid for extraction of oil and enhanced oil recovery (all claimed). ADVANTAGE - The Janus graphene nanosheet surfactant is economical and environmentally-friendly, and has excellent tensile strength and pot life, and enables extraction of oil with high recovery. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) emulsion, which comprises the Janus graphene nanosheet surfactant, water and oil; (2) method for extraction of oil from a formation, which involves adding Janus graphene nanosheet surfactant to the formation, contacting the surfactant with hydrocarbon of the formation, forming an emulsion of water, surfactant and hydrocarbon, removing the emulsion from the formation and extracting oil from the emulsion; (3) manufacture of Janus graphene nanosheet surfactant; (4) nanofluid, which comprises the Janus graphene nanosheet surfactant; and (5) enhanced oil recovery method.