Cross-linked graphene networks

Patent metadata

Field	Value
Publication number	US-9950931-B2
Application number	US-201314383800-A
Country	US
Kind code	B2
Filing date	Mar 7, 2013
Priority date	Mar 9, 2012
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

The present invention relates to a method for the production of cross-linked graphene and graphene oxide networks, which are selected from aerogels and xerogels with improved performance and characteristics thereof. The invention is also concerned with graphene and graphene oxide networks, which are selected from aerogels and xerogels produced by such processes and uses thereof.

First claim

The invention claimed is:

1. A method of producing an aerogel or xerogel comprising graphene, graphene oxide or a mixture thereof, comprising the steps of: a) dispersing graphene, graphene oxide or a mixture thereof in a solvent compatible therewith; b) cross-linking said graphene, graphene oxide or a mixture thereof by use of a coupling agent via functional groups present, on the graphene and/or the graphene oxide, or with a linking molecule comprising at least two functional sites capable of reacting with the surface of said graphene and/or graphene oxide, to form a covalently cross-linked gel network, wherein said coupling agent is selected from the group consisting of N,N′-dicyclohexylcarbodiimide (DCC), N,N′-diisopropylcarbodiimide (DIC), ethyl-(N′,N′-dimethylamino)propylcarbodiimide hydrochloride (EDC), 4-(N,N-dimethylamino) pyridine (DMAP), (benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate (BOP), (benzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate, bromotripyrrolidinophosphonium hexafluorophosphate, 0-(benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (HBTU), O-(benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate (TBTU), 0-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (HATU), 0-(6-chlorobenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (HCTU), 0-(3,4-Dihydro-4-oxo-1,2,3-benzotriazine-3-yl)-N,N,N′,N′ tetramethyluronium tetrafluoroborate (TDBTU), 3-(diethylphosphoryloxy)-1,2,3 benzotriazin-4(3H)-one (DEPBT) and carbonyldilmidazole (CDI), and mixtures thereof; and c) removing said solvent to produce a cross-linked aerogel or xerogel with a solvent content of less than 10%.

2. The method according to claim 1 , wherein said cross-linking is carried out directly on the graphene pristine surface with a molecule selected from the group consisting of bis(diazonium) salts and multifunctional molecules suitable for 1,3-dipolar cycloadditions or Bingel condensations, or by the reduction of the graphenes followed by the reaction of the graphenes with an electrophilic cross-linking molecule.

3. The method according to claim 1 , further comprising the step of capping residual functional groups on the graphenes prior to the removal of the solvent.

4. The method according to claim 1 , wherein said solvent is selected from the group consisting of dimethyl formamide, benzene, dichloromethane, chlorobenzene, dichlorobenzene, chloroform, toluene, xylene, dioxane, dimethylsulfoxide, tetrahydrofuran, amide solvents and mixtures thereof.

5. The method according to claim 1 , wherein said removal of solvent is carried out by solvent exchange with at least one solvent having lower surface tension than the solvent used in step (a).

6. The method according to claim 5 , wherein said solvent exchange is carried out using acetone, followed by C 3 -C 10 hydrocarbon, siloxane or fluorinated C 3 -C 10 hydrocarbon.

7. A method of producing an aerogel or xerogel comprising graphene, graphene oxide or a mixture thereof, comprising the steps of: a) dispersing graphene, graphene oxide or a mixture thereof in a solvent compatible therewith; b) cross-linking said graphene, graphene oxide or a mixture thereof via functional groups present on the graphene and/or the graphene oxide, or with a linking molecule comprising at least two functional sites capable of reacting with the surface of said graphene and/or graphene oxide, to form a covalently cross-linked gel network, wherein said cross-linking is carried out directly on the graphene pristine surface with a molecule selected from the group consisting of bis(diazonium) salts and multifunctional molecules suitable for 1,3-dipolar cycloadditions or Bingel condensations, or by the reduction of the graphenes followed by the reaction of the graphenes with an electrophilic cross-linking molecule; and c) removing said solvent to produce a cross-linked aerogel or xerogel with a solvent content of less than 10%.

8. The method according to claim 7 , wherein said cross-linking is achieved by using a coupling agent or by a dehydration step.

9. The method according claim 8 , wherein said cross-linking is formed using a coupling agent which is selected from the group consisting of N,N′-dicyclohexylcarbodiimide (DCC), N,N′-diisopropylcarbodiimide (DIC), ethyl-(N′,N′-dimethylamino)propylcarbodiimide hydrochloride (EDC), 4-(N,N-dimethylamino) pyridine (DMAP), (benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate (BOP), (benzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate, bromotripyrrolidinophosphonium hexafluorophosphate, 0-(benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (HBTU), O-(benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate (TBTU), 0-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (HATU), 0-(6-chlorobenzotriazol-1-yl)-N,N,N′N′-tetramethyluronium hexafluorophosphate (HCTU), 0-(3,4-Dihydro-4-oxo-1,2,3-benzotriazine-3-yl)-N,N,N′,N′ tetramethyluronium tetrafluoroborate (TDBTU), 3-(diethylphosphoryloxy)-1,2,3 benzotriazin-4(3H)-one (DEPBT) and carbonyldilmidazole (CDI), and mixtures thereof.

10. The method according to claim 7 , further comprising the step of capping residual functional groups on the graphenes prior to the removal of the solvent.

11. The method according to claim 7 , wherein said solvent is selected from the group consisting of dimethyl formamide, benzene, dichloromethane, chlorobenzene, dichlorobenzene, chloroform, toluene, xylene, dioxane, dimethylsulfoxide, tetrahydrofuran, amide solvents and mixtures thereof.

12. The method according to claim 7 , wherein said removal of solvent is carried out by solvent exchange with at least one solvent having lower surface tension than the solvent used in step (a).

13. The method according to claim 12 , wherein said solvent exchange is carried out using acetone, followed by C 3 -C 10 hydrocarbon, siloxane or fluorinated C 3 -C 10 hydrocarbon.

Assignees

• The Bio Nano Centre Ltd
• Univ King Abdulaziz

Inventors

• Gallastegui Ainara Garcia
• Shaffer Milo
• Alyoubi Abdulrahman O
• Asiri Abdullah M

Classifications

• H05B3/145

  Carbon only, e.g. carbon black, graphite · CPC title

• C01B32/182

  Graphene · CPC title

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title

• C07D303/40

  by ester radicals · CPC title

• C01B32/23

  Oxidation · CPC title