Composite for oil-water separation, synthesis methods and applications of same

1. A method of synthesizing a composite usable for oil-water separation, comprising:

surface nanostructuring pristine powders to form nanostructured powders having surfaces with nanoscale features; and

coating single or multilayers of one or more low surface energy oligomers, polymers, or their composites with other materials on the surfaces of the nanostructured powders,

wherein the surface nanostructuring process comprises a hot water treatment (HWT) of the pristine powders, wherein the HWT is performed with the assistance of microwave, infrared light heating, and/or in a high pressure container; and

wherein the surface nanostructuring process comprises growing the nanoscale features on the surfaces of the pristine powders through a cross-deposition mechanism during the HWT.

2. The method of claim 1 , wherein the pristine powders comprise a metal, an alloy, a metal oxide, a compound of metals with non-metallic materials, a non-metallic material, an insulator, a conductor, a semiconductor, or a combination thereof.

3. The method of claim 1 , wherein the low surface energy oligomer or polymer has a surface energy lower than that of water and higher than that of oil.

4. The method of claim 3 , wherein the composite is hydrophobic or superhydrophobic, and oleophilic or superoleophilic, wherein the composite operably repels water and absorbs oil.

5. The method of claim 1 , wherein the low surface energy oligomer or polymer has a surface energy lower than that of oil and higher than that of water.

6. The method of claim 5 , wherein the composite is oleophobic or superoleophobic, and hydrophilic or superhydrophilic, wherein the composite operably repels oil and absorbs water.

7. The method of claim 1 , wherein the HWT comprises:

mixing the pristine powders in water to form a mixture thereof; and

heating the mixture at temperatures higher than room temperature for a period of time to form the nanostructured powders having the surfaces with nanoscale features.

8. The method of claim 1 , wherein the cross-deposition mechanism comprises placing the pristine powders of non-metallic powders across a metal substrate during HWT, wherein molecules that migrate through water and deposit on the metal substrate to form nanostructures deposit on the neighboring non-metallic powders and form a layer of HWT-nanostructures.

9. The method of claim 1 , wherein the coating process is performed by a surface energy reduction process including solution immersion and oven evaporation.

10. The method of claim 1 , wherein the coating process is performed by pulsed laser deposition, evaporative deposition, sputter deposition, spray coating, paintbrush, or spin coating.

11. The method of claim 1 , further comprising, prior to the surface nanostructuring process, a pretreatment process to activate the surface of the pristine powders, wherein the pretreatment process includes acid dipping or plasma exposure.

12. A method of synthesizing a composite usable for oil-water separation, comprising:

surface nanostructuring a pristine powder or porous material to form nanostructured powder or porous material having surfaces with nanoscale features; and

coating single or multilayers of a self-assembled monolayer (SAM) polymer on the surfaces of the nanostructured powder or porous material, wherein the SAM polymer is 1H, 1H, 2H, 2H-perfluorodecyltrichlorosilane (FDTS) or 1-Dodecanethiol (DDT),

wherein the surface nanostructuring process comprises a hot water treatment (HWT) of the pristine powders, wherein the HWT is performed with the assistance of microwave, infrared light heating, and/or in a high pressure container, and

wherein the surface nanostructuring process comprises growing the nanoscale features on the surfaces of the pristine powder or porous material through a cross-deposition mechanism during the HWT.

13. The method of claim 12 , wherein the pristine powder or porous material comprises a metal, an alloy, a metal oxide, a compound of metals with non-metallic materials, a non-metallic material, an insulator, a conductor, a semiconductor, or a combination thereof.