Methods for making graphene oxide gels

Patent metadata

Field	Value
Publication number	US-12024433-B2
Application number	US-201816611131-A
Country	US
Kind code	B2
Filing date	May 4, 2018
Priority date	May 5, 2017
Publication date	Jul 2, 2024
Grant date	Jul 2, 2024

Abstract

Methods for reversibly forming graphene oxide gels by reacting graphene oxide dispersed in an aqueous solution with organic amines or quaternary phosphonium salts. Also provided are methods of forming anhydrous graphene oxide dispersions.

First claim

The invention claimed is:

1. A method of forming a graphene oxide gel comprising the steps:
providing an aqueous dispersion of graphene oxide, wherein the aqueous dispersion further comprises an inorganic acid, and the aqueous dispersion is acidic;
adding a reactant selected from the group consisting of organic amines, quaternary ammonium salts and phosphonium salts,
wherein the organic amine is selected from the group consisting of alkyl amines, heterocyclic amines, polymeric amines, spiro tetramines and combinations thereof;
wherein the aqueous dispersion of graphene oxide has a graphene oxide concentration in the range from about 0.1 g/L to about 5 g/L and the reactant has a total organic amine concentration or total phosphonium salt concentration in the range from about 10 mM to about 70 mM, and
stirring the mixture to form the graphene oxide hydrogel.

2. The method of claim 1 wherein the reactant is an organic amine or quaternary ammonium salt, and the organic amine or quaternary ammonium salt is selected from the group consisting of primary organic amines, secondary organic amines, tertiary organic amines, quaternary ammonium salts, and combinations thereof.

3. The method of claim 2 wherein the reactant is selected from the group consisting of triethylamine, diisopropylethylamine, tetrabutylammonium hydroxide, 6-aminohexanoic acid, HEPES, N,N-dimethyldodecylamine, diisopropylamine, hexylamine, hexadecylamine, 4,4′-dipyridyl, tris(2-aminoethyl)amine, benzyltriphenylphosphonium chloride, methyltrioctylammonium chloride, dodecyltrimethylammonium chloride, 1,12-diaminododecane, tetrakis(4-aminophenyl)methane, and combinations thereof.

4. The method of claim 1 further comprising the step of isolating the resulting graphene oxide hydrogel.

5. The method of claim 4 wherein the graphene oxide hydrogel is isolated by filtering.

6. The method of claim 4 wherein the graphene oxide hydrogel is isolated by centrifugation.

7. The method of claim 1 wherein the ratio of the reactant to graphene oxide is from about 0.9 mmol reactant per gram graphene oxide to about 400 mmol reactant per gram graphene oxide.

8. The method of claim 1 wherein the total organic amine concentration or total phosphonium salt concentration is about 40 mM.

9. The method of claim 1 wherein the concentration of the inorganic acid is in the range from about 0.004 to about 2 M.

10. The method of claim 1 wherein the inorganic acid is selected from the group consisting of sulfuric acid and hydrochloric acid.

11. The method of claim 4 further comprising the step of lyophilizing the graphene oxide to form a graphene oxide aerogel.

12. The method of claim 11 further comprising the step of reducing the graphene oxide aerogel to form a graphene aerogel.

13. The method of claim 12 wherein the reducing step comprises thermal reduction.

14. The method of claim 12 wherein the reducing step comprises chemical reduction.

15. A method of forming a graphene oxide gel comprising the steps:
providing an aqueous dispersion of graphene oxide, wherein the aqueous dispersion is acidic;
adding a reactant selected from the group consisting of organic amines and phosphonium salts,
wherein the organic amine is selected from the group consisting of alkyl amines, arylamines, heterocyclic amines, polymeric amines, spiro tetramines and combinations thereof;
wherein the ratio of the reactant to graphene oxide is from about 0.9 mmol reactant per gram graphene oxide to about 400 mmol reactant per gram graphene oxide;
wherein the total organic amine concentration or total phosphonium salt concentration is in the range from about 10 mM to about 70 mM; and
stirring the mixture to form the graphene oxide hydrogel.

16. A method of forming a graphene oxide gel comprising the steps:
providing an aqueous dispersion of graphene oxide, wherein the aqueous dispersion is acidic;
adding a reactant selected from the group consisting of organic amines and phosphonium salts,
wherein the aqueous dispersion of graphene oxide has a graphene oxide concentration in the range from about 0.1 g/L to about 5 g/L and the reactant has a total organic amine concentration or total phosphonium salt concentration is about 40 mM; and
stirring the mixture to form the graphene oxide hydrogel.

Assignees

• Sigma Aldrich Co Llc

Inventors

• Luedtke Avery

Classifications

• Y02E60/13

  Energy storage using capacitors · CPC title

• H01M4/133

  Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01G11/32

  Carbon-based · CPC title

• B01J13/0091

  Preparation of aerogels, e.g. xerogels · CPC title

• B01J13/0056

  containing inorganic material and water · CPC title