EFFICIENT SURFACE FUNCTIONALIZATION FOR SCALE-UP SYNTHESIS OF JANUS CARBON NANOFLUIDS

1 . A method of preparing an enhanced oil recovery composition comprising:

carbonizing a waste carbon material to provide carbon microparticles having a hydrophobic surface;

functionalizing the carbon microparticles with an alkaline solution such that the carbon microparticles comprise a hydrophilic surface; and

grinding the carbon microparticles to provide carbon nanoparticles, wherein the carbon nanoparticles comprise the hydrophilic surface and the hydrophobic surface.

2 . The method of claim 1 , further comprising mixing the carbon nanoparticles with an aqueous-based fluid to provide an enhanced oil recovery fluid.

3 . The method of claim 1 , wherein the waste carbon material comprises a waste plastic material or a biomass waste.

4 . The method of claim 3 , wherein the waste plastic material comprises a polymer selected from the group consisting of polypropylene (PP), polystyrene (PS), acrylonitrile butadiene styrene (ABS), polyethylene terephthalate (PET), polyester (PES), polyamide (PA), polyvinyl chloride (PVC), polyurethane (PU), polycarbonate (PC), polyvinylidene chloride (PVDC), polyethylene (PE), and combinations thereof.

5 . The method of claim 3 , wherein the waste plastic material is a plastic waste bottle.

6 . The method of claim 3 , wherein the biomass waste comprises a biomass waste selected from a group consisting of seaweed, algae, coffee, tea leaves, fruit peels, shells of nuts, and combinations thereof.

7 . The method of claim 3 , wherein the biomass waste comprises a molecule selected from a group of starch, chitin, lignin, cellulose, and combinations thereof.

8 . The method of claim 1 , wherein carbonizing the waste carbon material comprises heating the waste carbon material at a temperature in a range of 300 to 550° C.

9 . The method of claim 1 , wherein the carbon microparticles have an average particle size ranging 5 to 500 μm.

10 . The method of claim 1 , wherein functionalizing the carbon microparticles with the alkaline solution comprises ultrasonicating the carbon microparticles in the alkaline solution for an amount of time from 1 to 15 minutes.

11 . The method of claim 10 , wherein functionalizing the carbon microparticles with the alkaline solution further comprises heating the carbon microparticles after ultrasonicating at a temperature in a range of 300 to 550° C.

12 . The method of claim 1 , wherein the alkaline solution is a solution of potassium hydroxide.

13 . The method of claim 1 , wherein the alkaline solution has a concentration in a range of 1.0 to 4.0M.

14 . The method of claim 1 , wherein the hydrophilic surface functionality is a hydroxide.

15 . The method of claim 1 , wherein grinding the carbon microparticles comprises ball milling the carbon microparticles for an amount of time from 0.5 to 8 hours with a speed of 2000 to 4000 rpm.

16 . The method of claim 1 , wherein the carbon nanoparticles have an average particle size ranging from 10 to 2,000 nm.

17 . The method of claim 2 , wherein the aqueous-based fluid is water, seawater, or brine.

18 . The method of claim 2 , wherein the aqueous-based fluid comprises one or more additives selected from the group consisting of surfactant, stabilizers, and combinations thereof.

19 . A method of enhanced oil recovery, comprising:

introducing the enhanced oil recovery composition of claim 2 into a hydrocarbon-bearing formation;

displacing hydrocarbons from the hydrocarbon-bearing formation; and

recovering the hydrocarbons.

20 . The method of claim 19 , wherein the carbon nanoparticles are present in an amount ranging from 0.001 to 3.0 wt %.