Surfactant for enhanced oil recovery
A Janus graphene nanosheet (JGN) surfactant formed from a two-dimensional graphene oxide sheet and functionalized to produce an amphiphilic graphene nanosheet. The JGN may be a component of a nanofluid utilized in nanofluid flooding for oil recovery. The JGN may also be used as solid surfactants to form emulsions for oil recovery.
1. A tertiary oil recovery surfactant, wherein said surfactant comprises:
a nanofluid, wherein said nanofluid comprises ethanol and water; and
0.005 wt % of an asymmetrical Janus graphene nanosheet (JGN), wherein the JGN comprises: a single layer two dimensional graphene oxide sheet, wherein said graphene oxide sheet is about 1 nm thick and said graphene oxide sheet comprises:
first face, and a second face, wherein said first face and said second face each comprise at least one oxygen-rich functional group;
a hydrophobic species linked to said first face by said oxygen rich functional group; and a hydrophilic species linked to the second face, wherein the hydrophilic species is at least one of hydroxyl, epoxy, and carboxyl and wherein said surfactant has a density of about 0.2 to 1.5 g cm −3 , and wherein said tertiary oil recovery surfactant comprises a total oil recovery factor of about 78%.
2. The surfactant of claim 1 , wherein said nanosheet further comprises a specific surface area of about 500 to about 5000 m2/g.
3. The surfactant of claim 1 , wherein said nanosheet comprises an aspect ratio of about 10 to 1000.
4. The surfactant of claim 1 , wherein said nanosheet adsorbs a greater surface area of oil droplets as compared to the same mass of spherical nanoparticle surfactants.
5. The surfactant of claim 1 , wherein said nanosheet comprises a tensile strength of about 10-60 GPa.
6. An emulsion comprising: the surfactant of claim 1 ; water; and an oil.