# US 9,751,760 B2 · Atomically thin crystals and films and process for making same

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 9,751,760 B2
- Document ID: US9751760B2
- Status: Granted
- Kind: B2
- Application number: 14/410,387
- Filed: 2013-06-28
- Published: 2015-11-12
- Granted: 2017-09-05
- Earliest claimed: 2012-06-28
- Assignees: The Provost, Fellows, Foundation Scholars, and the Other Members of Board, of the College of the Holy and Undivided Trinity of Queen Elizabeth Near Dublin
- Applicants: The Provost, Fellows, Foundation Scholars & the Other Members of Board, of the College of the Holy & Undiv. Trinity of Queen Elizabeth Near Dublin
- Inventors: Jonathan Coleman; Umar Khan
- Web page: https://patentgrep.com/patent/US9751760B2

## CPC

- C01B 13/145: {After-treatment of oxides or hydroxides, e.g. pulverising, drying, decreasing the acidity}
- B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites
- B82Y 40/00: Manufacture or treatment of nanostructures
- C01B 19/007: {Tellurides or selenides of metals (C01B19/002 takes precedence)}
- C01B 19/04: Binary compounds {including binary selenium-tellurium compounds (C01B19/004, C01B19/005, C01B19/007 take precedence)}
- C01B 21/0648: {After-treatment, e.g. grinding, purification (transformation of hexagonal into cubic or wurtzitic boron nitride C04B35/5831)}
- C01B 21/083: containing one or more halogen atoms
- C01B 32/19: by exfoliation
- C01G 1/02: Oxides
- C01G 1/12: Sulfides
- C01G 23/04: Oxides; Hydroxides
- C01G 25/02: Oxides
- C01G 27/02: Oxides
- C01G 31/02: Oxides
- C01G 33/00: Compounds of niobium
- C01G 35/00: Compounds of tantalum
- C01G 37/02: Oxides or hydrates thereof
- C01G 39/02: Oxides; Hydroxides
- C01G 41/02: Oxides; Hydroxides
- C01G 47/00: Compounds of rhenium
- C01G 49/02: Oxides; Hydroxides {(C01G49/0018 takes precedence)}
- C01G 55/004: {Oxides; Hydroxides}
- C01G 99/00: Subject matter not provided for in other groups of this subclass
- H01B 1/06: mainly consisting of other non-metallic substances
- H01B 1/08: oxides
- H01B 1/10: sulfides
- H01B 3/02: mainly consisting of inorganic substances
- H01B 3/10: metallic oxides (ceramics H01B3/12)
- C01P 2002/01: depicted by a TEM-image
- C01P 2002/20: Two-dimensional structures
- C01P 2004/03: obtained by SEM
- C01P 2004/04: obtained by TEM, STEM, STM or AFM
- C01P 2004/24: Nanoplates, i.e. plate-like particles with a thickness from 1-100 nanometer
- Y10T 428/2991: Coated
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- C01G: COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts or peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium, or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds containing nitrogen, other non-metals and metal C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanamide C01C3/16; thiocyanates C01C3/20)
- H01B: CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES (selection for magnetic properties H01F1/00; waveguides H01P {; printed circuits H05K})
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

The invention provides a process for exfoliating a 3-dimensional layered material to produce a 2-dimensional material, said process comprising the steps of mixing the layered material in a solvent to provide a mixture; applying energy, for example ultrasound, to said mixture, and removing the energy applied to the mixture, such that sedimentation of the 2-dimensional material out of solution as a weakly re-aggregated, exfoliated 2-dimensional material is produced. The invention provides a fast, simple and high yielding process for separating 3-dimensional layered materials into individual 2-dimensional layers or flakes, which do not strongly re-aggregate, without utilising hazardous solvents.

## Claims

### Claim 1

A process for exfoliating a 3-dimensional layered material to produce a 2-dimensional material, said process comprising the steps of:
mixing the layered material in water to provide a mixture without the use of a surfactant;
applying energy to said mixture to exfoliate the 3-dimensional layered material and produce dispersed exfoliated 2-dimensional material;
removing the energy applied to the mixture, such that sedimentation of the 2-dimensional material out of solution as a weakly re-aggregated, exfoliated 2-dimensional material is produced; and
removing the water from the re-aggregated exfoliated 2-dimensional material to form a solid of re-aggregated exfoliated 2-dimensional material ready for storage,
wherein the 3-dimensional layered material is selected from the group consisting of graphite, a transition metal dichalcogenide (TMD), transition metal oxides, boron nitride (BN), Bi2Te3, Sb2Te3, TiNCl, or any other inorganic layered compound,
wherein the step of removing the water is by decantation, vacuum filtration or accelerated evaporation, and
wherein the re-aggregated exfoliated 2-dimensional material is washed with a volatile liquid selected from the group consisting of methanol, ethanol, propanol or acetone.

### Claim 2 (depends on 1)

A process according to claim 1, further comprising the step of re-dispersing the re-aggregated exfoliated 2-dimensional material in any one of the solvents selected from the group consisting of n-methyl pyrrolidone (NMP), cyclohexylpyrrolidone, di-methyl formamide, Cyclopentanone (CPO), Cyclohexanone, N-formyl piperidine (NFP), Vinyl pyrrolidone (NVP), 1,3-Dimethyl-2-imidazolidinone (DMEU), Bromobenzene, Benzonitrile, N-methyl-pyrrolidone (NMP), Benzyl Benzoate, N,N′-Dimethylpropylene urea, (DMPU), gamma-Butrylactone (GBL), Dimethylformamide (DMF), N-ethyl-pyrrolidone (NEP), Dimethylacetamide (DMA), Cyclohexylpyrrolidone (CHP), DMSO, Dibenzyl ether, Chloroform, Isopropylalcohol (IPA), Cholobenzene, 1-Octyl-2-pyrrolidone (N8P), 1-3 dioxolane, Ethyl acetate, Quinoline, Benzaldehyde, Ethanolamine, Diethyl phthalate, N-Dodecyl-2-pyrrolidone (N12P), Pyridine, Dimethyl phthalate, Formamide, Vinyl acetate, Acetone, or a water-surfactant solution.

### Claim 3 (depends on 2)

A process according to claim 2, wherein the water-surfactant solution comprises a solution of water and a surfactant selected from the group consisting of sodium cholate (NaC), sodium dodecylsulphate (SDS), sodium dodecylbenzenesulphonate (SDBS), lithium dodecyl sulphate (LDS), deoxycholate (DOC), taurodeoxycholate (TDOC), polyoxyethylene (40) nonylphenyl ether, polyethylene glycol p-(1,1,3,3-tetramethylbutyl)-phenyl ether (Triton-X 100® (TX-100)).

### Claim 4 (depends on 2)

A process according to claim 2, further comprising the step of applying energy to the re-dispersed re-aggregated exfoliated 2-dimensional material.

### Claim 5 (depends on 1)

A process according to claim 1, wherein the layered materials have the formula MXn, where 1≦n≦3.

### Claim 6 (depends on 1)

A process according to claim 1, wherein the layered materials have the formula MXn, where 1≦n≦3 and wherein M is selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mn, Mo, W, Tc, Re, Ni, Pd, Pt, Fe and Ru, and X is selected from the group consisting of O, S, Se, and Te.

### Claim 7 (depends on 1)

A process according to claim 1, wherein the applied energy is ultrasound.