Ultrathin, graphene-based membranes for water treatment and methods of their formation and use

Patent metadata

Field	Value
Publication number	US-10092882-B2
Application number	US-201415103642-A
Country	US
Kind code	B2
Filing date	Dec 10, 2014
Priority date	Dec 10, 2013
Publication date	Oct 9, 2018
Grant date	Oct 9, 2018

Abstract

Methods are generally provided for forming a membrane. In one embodiment, the method includes: dispersing GO nanoparticles in a solvent; depositing the GO nanoparticles on a support to form a GO membrane; and reducing the GO membrane to form a rGO membrane. Also provided is the rGO membrane formed from such methods, along with a plurality of stacked rGO layers. Methods are also provided for separating water from a water/oil emulsion by, for example, passing water through the rGO membrane.

First claim

What is claimed:

1. A method of forming a membrane, the method comprising:
dispersing single-layered graphene oxide powder in deionized water to form a single-layered graphene oxide dispersion;
sonicating the dispersion;
centrifuging the dispersion to remove large particles and aggregates from the dispersion;
thereafter, filtering the dispersion through a porous support such that a graphene oxide membrane of layered graphene oxide nanoflakes is formed on the support, the graphene oxide membrane having a thickness of about 2 nm to about 5 nm;
thereafter, reducing the graphene oxide membrane to form a reduced graphene oxide membrane wherein reducing the graphene oxide membrane comprises heating the graphene oxide membrane to a reducing temperature of about 200° C. to about 250° C. in a vacuum of about 1 torr to about 5 torr, or comprises heating the graphene oxide membrane to a reducing temperature of about 150° C. to about 240° C. in the presence of hydrogen, or comprises exposure of the graphene oxide membrane to hydrogen plasma; and
thereafter, etching the reduced graphene oxide membrane with electromagnetic radiation having a wavelength of about 400 nm to about 10 nm or with steam to generate pores of a predetermined size in the reduced graphene oxide membrane.

2. The method of claim 1 , wherein the support comprises aluminum oxide.

3. The method of claim 1 , wherein the support comprises an anodic aluminum oxide porous support.

4. The method of claim 1 , wherein the support defines pores having an average size of about 0.3 nm to about 20 nm.

5. The reduced graphene oxide membrane formed from the method of claim 1 .

6. A method of separating water from a water/oil emulsion, the method comprising passing water through the reduced graphene oxide membrane of claim 5 .

7. The method of claim 1 , wherein the porous support is a polymer support.

8. The method of claim 7 , wherein the polymer is a polyamide.

9. The method of claim 7 , wherein the polymer is a cellulose acetate.

10. The method of claim 1 , wherein the predetermined size of the pores of the reduced graphene oxide membrane is from about 0.3 nm to about 20 nm.

11. The method of claim 1 , wherein the predetermined size of the pores of the reduced graphene oxide membrane is from about 0.4 nm to about 10 nm.

Assignees

• Univ South Carolina

Inventors

• Yu Miao

Classifications

• B01D71/021

  Carbon · CPC title

• B01D67/0069

  by deposition from the liquid phase, e.g. electrochemical deposition (B01D67/0046 takes precedence) · CPC title

• B01D69/125

  In situ manufacturing by polymerisation, polycondensation, cross-linking or chemical reaction · CPC title

• B01D2323/10

  Specific pressure applied · CPC title

• C02F2101/325

  Emulsions · CPC title