Laminate membranes comprising a two-dimensional layer comprising polyaromatic functionalities

Patent metadata

Field	Value
Publication number	US-10913035-B2
Application number	US-201716085098-A
Country	US
Kind code	B2
Filing date	Apr 5, 2017
Priority date	Apr 6, 2016
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

This invention relates to membranes of two dimensional material and their uses in filtration. The membranes may include polyaromatic molecules which provide a improvement in the rejection observed for small solutes. The two dimensional material may be a transition metal dichalcogenide (TMDC) or hexagonal boron nitride (hBN).

First claim

The invention claimed is:

1. A laminate membrane comprising:
a plurality of nanoplatelets of a two-dimensional material comprising a transition metal dichalcogenide (TMDC) and/or hexagonal boron nitride (hBN), wherein each individual nanoplatelet is impermeable to liquid and the plurality of nanoplatelets are stacked in such a way as to form capillary-like pathways between the faces and sides of the nanoplatelets; and
a plurality of polyaromatic molecules covalently bonded to the two-dimensional material.

2. The membrane of claim 1 , wherein the two-dimensional material is a TMDC.

3. The membrane of claim 1 , wherein the plurality of nanoplatelets is a mixture of a plurality of nanoplatelets of a first two-dimensional material comprising a TMDC and a plurality of nanoplatelets of a second two-dimensional material selected from the group consisting of a TMDC, graphene, and hBN.

4. The membrane of claim 1 , wherein the polyaromatic molecules are dye molecules.

5. The membrane of claim 4 , wherein the dye molecules comprise sunset yellow and/or crystal violet.

6. The membrane of claim 1 , wherein the plurality of nanoplatelets is obtained from the corresponding bulk layered inorganic material using a solvent exfoliation method.

7. The membrane of claim 1 , wherein the laminate membrane is comprised in a composite with a porous material.

8. A method of reducing the amount of one or more solutes in a liquid to produce a product liquid depleted in said solute or solutes; the method comprising:
(a) contacting a first face of a laminate membrane with the liquid comprising the one or more solutes, wherein the laminate membrane comprises a plurality of nanoplatelets of a two-dimensional material comprising a transition metal dichalcogenide (TMDC) and/or hexagonal boron nitride (hBN); and a plurality of polyaromatic molecules covalently bonded to the two-dimensional material; wherein each individual nanoplatelet is impermeable to liquid and the plurality of nanoplatelets are stacked in such a way as to form capillary-like pathways between the faces and sides of the nanoplatelets, causing the liquid to pass through the capillary-like pathways between the faces and sides of the nanoplatelets; and
(b) recovering the product liquid depleted in said solute or solutes from or downstream from a second face of the membrane;
(c) optionally, recovering the solute or solutes from the first face of the membrane.

9. The method of claim 8 , wherein the one or more solutes comprise one or more ions and corresponding counterions in which both ions have a hydration radius that is no larger than 1 nm.

10. The method of claim 8 , wherein the method is a filtration method and wherein the product liquid is recovered as a liquid from or downstream from the second face of the membrane without the liquid having undergone a phase change.

11. The method of claim 8 , wherein the liquid is an aqueous liquid.

12. The method of claim 8 , wherein the one or more solutes comprise one or more ions and corresponding counterions in which both ions have a hydration radius that is no larger than 0.45 nm.

13. The method of claim 12 , wherein the one or more solutes includes NaCl.

14. A method of reducing the amount of one or more non-ionic solutes in a liquid to produce a product liquid depleted in said solute or solutes; the method comprising:
(a) contacting a first face of a laminate membrane with the liquid comprising the one or more solutes, wherein the laminate membrane comprises a plurality of nanoplatelets of a two-dimensional material comprising a transition metal dichalcogenide (TMDC) and/or hexagonal boron nitride (hBN); and a plurality of polyaromatic molecules covalently bonded to the two-dimensional material; wherein each individual nanoplatelet is impermeable to liquid and wherein the plurality of nanoplatelets are stacked in such a way as to form capillary-like pathways between the faces and sides of the nanoplatelets, causing the liquid to pass through the capillary-like pathways between the faces and sides of the nanoplatelets; and
(b) recovering the solute or solutes liquid from or downstream from a second face of the membrane;
(c) optionally, recovering any remaining product from the first face of the membrane;
wherein the one or more solutes are each non-ionic species having a hydration radius that is no larger than 10 nm.

15. The method of claim 14 , wherein the one or more solutes comprise non-ionic species having a hydration radius that is no larger than 1 nm.

16. The method of claim 14 , wherein the method is a filtration method and wherein the product liquid is recovered as a liquid from or downstream from the second face of the membrane without the liquid having undergone a phase change.

17. The method of claim 16 , wherein the non-ionic solute or each non-ionic solute is an organic molecule.

18. The method of claim 14 , wherein the liquid is an organic solvent or solvent mixture.

19. The method of claim 14 , wherein the liquid is an aqueous liquid.

20. The method of claim 14 , wherein the method is a pervaporation method and the method of recovering the product liquid comprises allowing the liquid to evaporate from the second face of the membrane to form a vapour and subsequently condensing the vapour to form the product liquid.

21. The method of claim 20 , wherein the non-ionic solute is an alcohol and the liquid is either water or a second alcohol with a smaller hydration radius than the first alcohol.

22. The method of claim 14 , wherein the concentration of the one or more solutes in the product liquid is reduced by 50% or more relative to the concentration in the starting liquid.

23. The method of claim 14 , wherein the plurality of nanoplatelets is obtained from the corresponding bulk layered inorganic material using a solvent exfoliation method.

24. The method of claim 14 , wherein the plurality of nanoplatelets is a mixture of a plurality of nanoplatelets of a first two-dimensional material selected from the group consisting of a TMDC and hBN and a plurality of nanoplatelets of a second two-dimensional material selected from the group consisting of a TMDC, graphene, and hBN.

25. The method of claim 14 , wherein the two-dimensional material is a TMDC.

26. The method of claim 14 , wherein the two-dimensional material is hBN.

27. The method of claim 14 , wherein the laminate membrane is comprised in a composite with a porous material.

28. A method of producing a laminate membrane of claim 7 ; the method comprising:
a) depositing a plurality of nanoplatelets of a two-dimensional material onto a porous material to form the laminate membrane supported on the porous material; and
b) contacting a first side of the laminate membrane with a first solution comprising a first concentration of the polyaromatic molecules and contacting the second side of the laminate membrane with a second solution comprising a second concentration of the polyaromatic molecules, said second concentration being lower than said first concentration, to covalently bond the plurality of polyaromatic molecules to the two-dimensional material to provide a membrane of claim 7 .

29. The method of claim 28 , wherein the method further comprises:
obtaining the plurality of nanoplatelets of the two-dimensional material from the corresponding bulk layered inorganic material using a solvent

Assignees

• Univ Manchester

Inventors

• Dryfe Robert
• Bissett Mark

Classifications

• B01D69/1213

  Laminated layers · CPC title

• B01D67/0093

  Chemical modification · CPC title

• B01D71/02 Primary

  Inorganic material · CPC title

• B01D67/0046

  by slurry techniques, e.g. die or slip-casting · CPC title

• B01D2323/40

  in-situ membrane formation · CPC title