Method for separating nonpolar compounds from aqueous solutions

Patent metadata

Field	Value
Publication number	US-12371350-B2
Application number	US-202318117247-A
Country	US
Kind code	B2
Filing date	Mar 3, 2023
Priority date	Jul 24, 2019
Publication date	Jul 29, 2025
Grant date	Jul 29, 2025

Abstract

A composite material of polyurethane foam having a layer of reduced graphene oxide and polystyrene is described. This composite material may be made by contacting a polyurethane foam with a suspension of reduced graphene oxide, drying, and then irradiating in the presence of styrene vapor. The composite material has a hydrophobic surface that may be exploited for separating a nonpolar phase, such as oil, from an aqueous solution.

First claim

The invention claimed is:

1. A method of separating a nonpolar compound from an aqueous solution in a mixture, comprising:
contacting the mixture with a composite material,
wherein the composite material adsorbs 8-25 times its weight of the nonpolar compound;
wherein the composite material comprises:
a polyurethane foam comprising an open-cell structure having an exterior surface and containing pores having an interior pore surface;
a coating layer of reduced graphene oxide (r-GO) on at least 70% of a total of the exterior surface and interior pore surface and in contact with the polyurethane foam; and
a layer of polystyrene in contact with both the surface of the layer of r-GO and directly in contact with the surface of the polyurethane foam, wherein an average thickness of the polystyrene layer is from 500 nm to 4.5 μm; and

wherein the composite material has pore diameters in a range of 50-500 μm.

2. The method of claim 1 , wherein the nonpolar compound is at least one selected from the group consisting of hexane, heptane, toluene, xylene, and a petroleum-derived liquid.

3. The method of claim 1 , wherein the composite material adsorbs less than 20% of its weight of the aqueous solution.

4. The method of claim 1 , wherein the contacting involves filtering the mixture through the composite material.

5. The method of claim 1 , further comprising:
compressing the composite material after the contacting to produce a discharged composite material, and
reusing the discharged composite material.

6. The method of claim 5 , wherein the discharged composite material comprises at least 90 wt % r-GO relative to a total weight of r-GO in the composite material.

7. The method of claim 5 , wherein the discharged composite material comprises at least 90 wt % polystyrene relative to a total weight of polystyrene in the composite material.

8. The method of claim 1 , wherein the composite material, the r-GO layer comprises nanoplatelets having a thickness of from 40 nm to 110 nm, diameters of from 5 μm to 45 μm and a length to thickness aspect ratio of from 40:1 to 1,200:1.

9. The method of claim 1 , wherein the composite material, the r-GO layer comprises carbon nanotubes at a weight percentage of from 5 wt % to 80 wt % relative to a total weight of the r-GO.

10. The method of claim 1 , wherein the composite material, the polystyrene is covalently bonded to the r-GO.

11. The method of claim 1 , wherein the composite material has an apparent contact angle with water of 130°-170°.

12. The method of claim 1 , wherein the composite material has a BET surface area in a range of 50-100 m 2 /g.

13. The method of claim 1 , wherein the composite material at least 70% of a total surface area of the exterior surface and the interior pore surface is comprised of the layer of polystyrene.

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Awadh Tawfik Abdo Saleh
• Baig Nadeem

Classifications

• B01J20/262

  obtained otherwise than by reactions only involving carbon to carbon unsaturated bonds, e.g. obtained by polycondensation (macromolecular compounds obtained otherwise than by reactions only involving unsaturated carbon-to-carbon bonds per se C08G) · CPC title

• C02F2101/32

  Hydrocarbons, e.g. oil · CPC title

• C02F1/285

  using synthetic organic sorbents · CPC title

• C02F1/281

  using inorganic sorbents · CPC title

• B01J20/327

  Polymers obtained by reactions involving only carbon to carbon unsaturated bonds · CPC title