Continuous production of exfoliated 2D layered materials by compressive flow

Patent metadata

Field	Value
Publication number	US-10882276-B2
Application number	US-201715716706-A
Country	US
Kind code	B2
Filing date	Sep 27, 2017
Priority date	Sep 30, 2016
Publication date	Jan 5, 2021
Grant date	Jan 5, 2021

Abstract

Described herein are methods for continuous production of an exfoliated two-dimensional (2D) material comprising passing a 2D material mixture through a convergent-divergent nozzle, the 2D material mixture comprising a 2D layered material and a compressible fluid. The method of the present disclosure employs physical compression and expansion of a flow of high-pressure gases, leaving the 2D layered material largely defect free to produce an exfoliated 2D layered in a simple, continuous, and environmentally friendly manner.

First claim

What is claimed is:

1. A method for continuous production of an exfoliated two-dimensional (2D) material comprising
a) providing a 2D layered material;
b) providing a compressible fluid;
c) mixing the 2D layered material with the compressible fluid thereby forming a 2D material mixture; and
d) passing the 2D material mixture through a convergent-divergent nozzle to exfoliate the 2D layered material before the compressible fluid intercalates the 2D layered material.

2. The method of claim 1 wherein the 2D layered material comprises graphite, graphene, boron nitride (BN), single-layer BN, molybdenum disulfide (MoS 2 ), single-layer MoS 2 , or any combination thereof.

3. The method of claim 1 wherein the compressible fluid comprises air, nitrogen, carbon dioxide, helium, or any combination thereof.

4. The method of claim 1 wherein a concentration of the 2D layered material in the 2D material mixture is about 0.01 milligrams per milliliter (mg/mL) to about 0.4 mg/mL.

5. The method of claim 1 wherein the convergent-divergent nozzle comprises a de Laval nozzle, a valve, an orifice, a thin tube, or any combination thereof.

6. The method of claim 5 wherein a valve comprises a needle valve, a butterfly valve, a globe valve, a pinch valve, an adjustable flow valve, a one-way flow valve, or any combination thereof.

7. The method of claim 1 , wherein passing the 2D material mixture through the convergent-divergent nozzle comprises applying a pressure to the 2D material mixture of about 200 pounds per square inch (psi) to about 4000 psi.

8. The method of claim 1 wherein the 2D material mixture enters the convergent-divergent nozzle at a velocity less than the speed of sound in the compressible fluid.

9. The method of claim 1 wherein the 2D material mixture exits the convergent-divergent nozzle at a velocity greater than the speed of sound in the compressible fluid.

10. The method of claim 1 , wherein the convergent-divergent nozzle has a throat dimension of about 0.005 millimeters (mm) to about 0.5 mm.

11. The method of claim 1 wherein the convergent-divergent nozzle has an inlet or an outlet dimension of about 3 mm to about 10 mm.

12. The method of claim 1 wherein the convergent-divergent nozzle has a length of about 15 centimeters (cm) to about 60 cm.

13. The method of claim 1 wherein the convergent-divergent nozzle has at least one of a throat-to-inlet dimension ratio and a throat-to-outlet dimension ratio of about 15 to about 60.

14. The method of claim 1 wherein a percent of the 2D layered material that produces the exfoliated 2D material is about 50% to about 100%.

15. The method of claim 1 wherein the exfoliated 2D material comprises a plurality of flakes with an aspect ratio of about 10 to about 300.

16. The method of claim 1 wherein the exfoliated 2D material comprises a plurality of flakes with an average thickness of about 0.35 nanometers (nm) to about 10 nm.

17. The method of claim 1 wherein the exfoliated 2D material comprises a plurality of flakes with an average length of about 50 nm to about 1,600 nm.

18. The method of claim 1 wherein the exfoliated 2D material comprises a plurality of flakes comprising at most about 20 layers.

19. The method of claim 1 wherein the 2D material mixture further comprises a solvent.

20. The method of claim 1 further comprising centrifuging the exfoliated 2D material.

21. The method of claim 20 wherein the centrifuging is performed at a rate of about 700 revolutions per minute (rpm) to about 4,000 rpm.

22. The method of claim 20 wherein the centrifuging is performed for a period of time of about 2 minutes to about 180 minutes.

23. A method for continuous production of exfoliated two-dimensional (2D) material comprising:
a) providing a 2D layered material;
b) providing a continuous flow of compressible fluid;
c) feeding the 2D layered material into the continuous flow of compressible fluid thereby forming a continuous flow of a mixture of the 2D layered material and compressible fluid; and
d) passing the continuous flow of the mixture of the 2D layered material and compressible fluid through a convergent-divergent nozzle to exfoliate the 2D layered material before the compressible fluid intercalates the 2D layered material.

Assignees

• Univ California

Inventors

• Kaner Richard B
• Nguyen Emily Phuong Nam
• Rizvi Syed Reza

Classifications

• C01P2004/24

  Nanoplates, i.e. plate-like particles with a thickness from 1-100 nanometer · CPC title

• C01G39/06

  Sulfides · CPC title

• C01B32/225 Primary

  Expansion; Exfoliation · CPC title

• C01B32/19 Primary

  by exfoliation · CPC title

• C01B21/0648

  After-treatment, e.g. grinding, purification (transformation of hexagonal into cubic or wurtzitic boron nitride C04B35/5831) · CPC title