Thermal storage units, components thereof, and methods of making and using them

Patent metadata

Field	Value
Publication number	US-2016209124-A1
Application number	US-201414915403-A
Country	US
Kind code	A1
Filing date	Aug 29, 2014
Priority date	Aug 29, 2013
Publication date	Jul 21, 2016
Grant date	—

Abstract

Sugar alcohol blends of galactitol and mannitol and compositions comprising such blends are disclosed as phase change materials (PCMs). A method of forming carbon nanotubes on a carbon substrate is described. Carbon substrates with carbon nanotubes, in particular, conformal layers of carbon nanotubes on carbon substrates, are also disclosed, as are methods of making and using these materials. Thermal storage units are also provided. The thermal storage units can comprise a heat exchange path through which a heat exchange medium flows, and a thermal storage medium in thermal contact with the heat exchange path.

First claim

What is claimed is:

1 . A composition comprising galactitol and mannitol in a weight ratio of from about 9:1 to about 1:9.

2 . The composition of claim 1 , wherein the weight ratio of galactitol to mannitol is from about 2.5:1 to about 1:1.5.

3 . The composition of any of claims 1 - 2 , wherein the weight ratio of galactitol to mannitol is about 1:1.

4 . The composition of any of claims 1 - 3 , wherein the amount of galactitol and mannitol is at least about 75 wt. % of the total composition.

5 . The composition of any of claims 1 - 4 , wherein the amount of galactitol and mannitol is at least about 90 wt. % of the total composition.

6 . The composition of any of claims 1 - 5 , wherein the amount of galactitol and mannitol is at least about 98 wt. % of the total composition.

7 . The composition of any of claims 1 - 6 , wherein the composition has a melting point of from about 150° C. to about 160° C.

8 . The composition of any of claims 1 - 7 , wherein the composition has a melting point of from about 151° C. to about 153° C.

9 . The composition of any of claims 1 - 8 , wherein the composition has a latent heat of fusion of from about 280 J/g to about 315 J/g.

10 . The composition of any of claims 1 - 9 , wherein the composition has a melting point of from about 300 J/g to about 310 J/g.

11 . The composition of any of claims 1 - 10 , wherein the galactitol and/or mannitol is oxidized, reduced, or functionalized with an alkyl, amino, amido, cyano, thio, or ester group at one or more positions.

12 . The composition of any of claims 1 - 11 , further comprising one or more of a viscosity modifier, an antimicrobial material, a fire retardant, an agent to prevent supercooling, a thickener, an antioxidant, or a corrosion inhibitor.

13 . The composition of any of claims 1 - 12 , further comprising one or more thermal storage materials selected from the group consisting of fatty acid, paraffin, polyethylene glycol, polyvinyl alcohol, glycerin, polyethylene, and crosslinked polyethylene.

14 . A microcapsule comprising the composition of any of claims 1 - 13 .

15 . A thermal composite comprising the composition of any of claims 1 - 13 and a thermal conductivity modulator.

16 . The thermal composite of claim 15 , wherein the thermal conductivity modulator comprises a metal or metal oxide.

17 . The thermal composite of claim 15 , wherein the thermal conductivity modulator comprises a graphitic foam.

18 . The thermal composite of claim 15 , wherein the graphitic foam is a hybrid ultrathin graphitic foam comprising nanotubes.

19 . A thermal storage device comprising the composition of any of claims 1 - 13 , the microcapsule of claim 14 , or the thermal composite of any of claims 15 - 18 .

20 . The thermal storage device of claim 19 , wherein the device is a shell tube device.

21 . A method of forming carbon nanotubes on a carbon substrate, comprising:
a. depositing a buffer layer on the carbon substrate by atomic layer deposition; b. depositing a catalyst on the carbon substrate and/or buffer layer; and c. contacting the carbon substrate with a working gas at an elevated temperature to thereby form carbon nanotubes on the carbon substrate.

22 . The method of claim 21 , wherein step a) is performed before step b).

23 . The method of claim 21 , wherein step b) is performed before step a).

24 . The method of any of claims 21 - 23 , wherein the carbon substrate is a carbon foam.

25 . The method of any of claims 21 - 24 , wherein the carbon substrate is a graphite foam.

26 . The method of any of claims 21 - 25 , wherein the carbon substrate is a graphite foam formed by chemical vapor deposition of graphene on a nickel foam, and the nickel is removed by electrolytic etching.

27 . The method of any of claims 21 - 26 , wherein the carbon substrate is a 3D printed graphite foam.

28 . The method of any of claims 21 - 27 , wherein the buffer layer is about 1 to about 10 nm thick.

29 . The method of any of claims 21 - 28 , wherein the buffer layer is about 5 nm thick.

30 . The method of any of claims 21 - 29 , wherein the buffer layer comprises a metal oxide.

31 . The method of any of claims 21 - 30 , wherein the buffer layer comprises aluminum oxide, zinc oxide, silicon oxide, or combinations thereof.

32 . The method of any of claims 21 - 31 , wherein the buffer layer comprises aluminum oxide.

33 . The method of any of claims 21 - 32 , wherein the buffer layer comprises a layer of aluminum oxide from about 2 to about 10 nm thick.

34 . The method of any of claims 21 - 33 , wherein the buffer layer comprises a layer of aluminum oxide about 5 nm thick.

35 . The method of any of claims 21 - 34 , wherein the catalyst is an iron catalyst.

36 . The method of any of claims 21 - 35 , wherein the catalyst is formed from ferrocene.

37 . The method of any of claims 21 - 36 , wherein the catalyst is deposited as a layer.

38 . The method of any of claims 21 - 37 , wherein the catalyst is deposited as a layer from about 2 to about 20 nm thick.

39 . The method of any of claims 21 - 38 , wherein the catalyst is deposited as particles.

40 . The method of any of claims 21 - 39 , wherein the catalyst is deposited as particles from about 2 to about 20 nm in size.

41 . The method of any of claims 21 - 40 , wherein the catalyst is deposited using atomic layer deposition.

42 . The method of any of claims 21 - 41 , wherein the catalyst is deposited using chemical vapor deposition.

43 . The method of any of claims 21 - 42 , wherein the catalyst is deposited by a vapor phase metal source.

44 . The method of any of claims 21 - 43 , wherein the carbon nanotubes are from 1 about to about 500 micrometers in length.

45 . The method of any of claims 21 - 44 , wherein the carbon nanotubes are from about 250 to about 500 micrometers in length.

46 . The method of any of claims 21 - 45 , wherein the carbon nanotubes are from about 1 to about 50 nm in diameter.

47 . The method of any of claims 21 - 46 , wherein the carbon nanotubes are about 10 nm in diameter.

48 . The method of any of claims 21 - 47 , wherein the carbon nanotubes comprise single walled nanotubes, double walled nanotubes, multi walled nanotubes, or a combination thereof.

49 . The method of any of claims 21 - 48 , wherein the carbon substrate is plasma treated prior to atomic layer deposition.

50 . The method of any of claims 21 - 49 , wherein the carbon substrate is oxygen-plasma treated prior to atomic layer deposition.

51 . The method of any of claims 21 - 50 , wherein the carbon substrate is oxygen-plasma treated for from about 1 to about 5 minutes prior to atomic layer deposition.

52 . The method of any of claims 21 - 51 , wherein the working gas comprises a hydrocarbon gas.

53 . The method of any of claims 21 - 52 , wherein the working gas com

Assignees

• Univ Texas

Inventors

• Da Silvaa Alexandre K
• Fleming Evan
• Shi Li
• Bielawski Christopher W
• Ruoff Rodney S
• Wen Shaoyi
• Ji hengxing
• Pettes Michael
• Paul Abhijit
• Paek Eunsu
• Pak Alexander J
• Sellan Daniel P

Classifications

• C23C16/44

  characterised by the method of coating (C23C16/04 takes precedence) · CPC title

• F28D20/021 Primary

  the latent heat storage material and the heat-exchanging means being enclosed in one container (F28D20/023 - F28D20/028 take precedence) · CPC title

• C09K5/063

  Materials absorbing or liberating heat during crystallisation; Heat storage materials · CPC title

• C01B2202/24

  Thermal properties · CPC title

• C01B2202/36

  Diameter · CPC title