Low density open cell organic foams, low density open cell carbon foams, and methods for preparing same

• US 5,945,084 A
• Filed: 07/05/1997
• Issued: 08/31/1999
• Est. Priority Date: 07/05/1997
• Status: Expired due to Term

• Current Assignee: Ocellus, Inc.
• Original Assignee: Ocellus, Inc.
• Inventors: Droege, Michael W.
• Primary Examiner(s): Foelak, Morton
• Application Number:
  US08/903,203
• Time in Patent Office: 787 Days
• Field of Search: 521/64, 521/181, 521/63, 521/136, 521/918, 423/447.4, 423/445 R, 501/99, 502/418
• US Class Current: 423/447.4
• CPC Class Codes: C04B 35/52 based on carbon, e.g. graphite
• CPC Class Codes: C04B 38/0022 obtained by a chemical conversion or reaction other than those relating to the setting or hardening of cement-like material or to the formation of a sol or a gel, e.g. by carbonising or pyrolysing preformed cellular materials based on polymers, organo-metallic or organo-silicon precursors
• CPC Class Codes: C04B 38/0045 by a process involving the formation of a sol or a gel, e.g. sol-gel or precipitation processes
• CPC Class Codes: C08G 8/22 Resorcinol
• CPC Class Codes: C08J 2361/00 Characterised by the use of condensation polymers of aldehydes or ketones with polyalcohols C08J2359/00; with polynitriles C08J2377/00; Derivatives of such polymers
• CPC Class Codes: C08J 3/075 Macromolecular gels
• CPC Class Codes: C08J 9/28 by elimination of a liquid phase from a macromolecular composition or article, e.g. drying of coagulum
• CPC Class Codes: C08J 9/283 a discontinuous liquid phase emulsified in a continuous macromolecular phase
• CPC Class Codes: C08J 9/286 the liquid phase being a solvent for the monomers but not for the resulting macromolecular composition, i.e. macroporous or macroreticular polymers
• CPC Class Codes: H01G 11/26 characterised by their structure, e.g. multi-layered, porosity or surface features
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors
• CPC Class Codes: Y10S 521/918 Physical aftertreatment of a cellular product

Abstract

This pertains to the general field of gels, foams, and aerogels, particularly, to low density open cell organic foams and low density open cell carbon foams, and methods for preparing them. These low density open cell organic foams are derived from organic gels which may be prepared from hydroxylated benzenes (such as phenol, catechol, resorcinol, hydroquinone, and phloroglucinol) and aldehydes (such as formaldehyde and furfural) using lower than conventional catalyst concentrations (e.g, an R/C value of greater than about 1000, yielding an initial room temperature pH typically lower than about 6.0). These organic foams are characterized by relatively large particle and pore sizes, high porosity, and high surface area. Low density open cell carbon foams derived from such organic foams are also shown, as are methods for preparing same. These carbon foams are also characterized by relatively large particle and pore sizes, high porosity, high surface area, and high electrical capacitance. Low density open cell carbon foam/carbon substrate composites and methods for preparing them are also shown.

Claims

1. A method for preparing an organic gel, said method comprising the steps of:

(a) forming a reaction mixture comprising one or more hydroxylated benzene compounds, one or more aldehydes, one or more catalysts, and water;

wherein the molar ratio of said hydroxylated benzene compounds to said catalysts in said reaction mixture, R/C, is greater than about 2000; and

,

(b) heating said reaction mixture to form said organic gel.

2. The method of claim 1 wherein, in said forming step, the weight of the hydroxylated benzene compounds and the aldehydes in the reaction mixture with respect to the total volume of the reaction mixture, R, is in the range of 30-80% w/v (weight to volume).

3. The method of claim 1 wherein said one or more hydroxylated benzene compound comprises resorcinol and said one or more aldehydes comprises formaldehyde.

4. The organic gel formed by the method of claim 1.

5. The organic gel formed by the method of claim 2.

6. A method for preparing a cured organic gel, said method comprising the steps of:

(a) forming a reaction mixture comprising one or more hydroxylated benzene compounds, one or more aldehydes, one or more catalysts, and water;

wherein the molar ratio of said hydroxylated benzene compounds to said catalysts in said reaction mixture, R/C, is greater than about 2000; and

,

(b) heating said reaction mixture at a gelation temperature for a gelation time to form an organic gel; and

,

(c) heating said organic gel at a curing temperature for a curing time to form said cured organic gel.

7. The method of claim 6 wherein, in said forming step, the weight of the hydroxylated benzene compounds and the aldehydes in the reaction mixture with respect to the total volume of the reaction mixture, R, is in the range of 30-80% w/v (weight to volume).

8. The method of claim 6 wherein said one or more hydroxylated benzene compound comprises resorcinol and said one or more aldehydes comprises formaldehyde.

9. The cured organic gel formed by the method of claim 6.

10. The cured organic gel formed by the method of claim 7.

11. A method for preparing a low density open cell organic foam, said method comprising the steps of:

(a) forming a reaction mixture comprising one or more hydroxylated benzene compounds, one or more aldehydes, one or more catalysts, and water;

wherein the molar ratio of said hydroxylated benzene compounds to said catalysts in said reaction mixture, R/C, is greater than about 2000; and

,

(b) heating said reaction mixture to form an organic gel; and

,

(c) removing at least a portion of the water from said organic gel to form said low density open cell organic foam.

12. The method of claim 11 wherein, in said forming step, the weight of the hydroxylated benzene compounds and the aldehydes in the reaction mixture with respect to the total volume of the reaction mixture, R, is in the range of 30-80% w/v (weight to volume).

13. The method of claim 11 wherein said one or more hydroxylated benzene compound comprises resorcinol and said one or more aldehydes comprises formaldehyde.

14. The method of claim 11 wherein said step of removing at least a portion of said water comprises a heating step.

15. The low density open cell organic foam formed by the method of claim 11.

16. The low density open cell organic foam formed by the method of claim 14.

23. A low density open cell organic foam according to claim 15 characterized by a density of 300 to 900 mg/cm³, a surface area of 200 to 1000 m² /g, and a meso-pore size distribution of 5 to 50 nm.

24. The low density open cell organic foam of claim 23, wherein said low density open cell organic foam is formed by at least partial evaporative removal of water from an organic gel, said organic gel formed by the reaction of one or more hydroxylated benzene compounds and one or more aldehydes in the presence of one or more catalysts and water.

25. The low density open cell organic foam of claim 23, wherein said low density open cell organic foam wherein the meso-pore size distribution is from about 10 to about 50 nm.

26. The low density open cell organic foam of claim 23, wherein said low density open cell organic foam wherein the meso-pore size distribution is from about 10 to about 25 nm.

27. The low density open cell organic foam of claim 23, wherein said low density open cell organic foam is colored orange to deep red.

17. A method for preparing a low density open cell organic foam, said method comprising the steps of:

(a) forming a reaction mixture comprising one or more hydroxylated benzene compounds, one or more aldehydes, one or more catalysts, and water;

wherein the molar ratio of said hydroxylated benzene compounds to said catalysts in said reaction mixture, R/C, is greater than about 2000; and

,

(b) heating said reaction mixture at a gelation temperature for a gelation time to form an organic gel;

(c) heating said organic gel at a curing temperature for a curing time to form a cured organic gel; and

,

(d) removing at least a portion of the water from said cured organic gel to form said low density open cell organic foam.

18. The method of claim 17 wherein, in said forming step, the weight of the hydroxylated benzene compounds and the aldehydes in the reaction mixture with respect to the total volume of the reaction mixture, R, is in the range of 30-80% w/v (weight to volume).

19. The method of claim 17 wherein said one or more hydroxylated benzene compound comprises resorcinol and said one or more aldehydes comprises formaldehyde.

20. The method of claim 17 wherein said step of removing at least a portion of said water comprises a heating step.

21. The low density open cell organic foam formed by the method of claim 17.

22. The low density open cell organic foam formed by the method of claim 20.

28. A method for preparing a low density open cell carbon foam, said method comprising the steps of:

(a) forming a reaction mixture comprising one or more hydroxylated benzene compounds, one or more aldehydes, one or more catalysts, and water;

wherein the molar ratio of said hydroxylated benzene compounds to said catalysts in said reaction mixture, R/C, is greater than about 2000; and

,

(b) heating said reaction mixture to form an organic gel;

(c) drying said organic gel to form a low density open cell organic foam; and

,

(d) pyrolyzing said low density open cell organic foam at a high temperature to form said low density open cell carbon foam.

34. A low density open cell carbon foam according to claim 38 characterized by a density of 300 to 900 mg/cm³, a surface area of 200 to 800 m² /g, a meso-pore size distribution of 5 to 50 nm, and an electrical capacitance of 10 to 80 F/g.

35. The low density open cell carbon foam of claim 34, wherein said low density open cell carbon foam is formed by pyrolysis of a low density open cell organic foam, said low density open cell organic foam formed by at least partial evaporative removal of water from an organic gel, said organic gel formed by the reaction of one or more hydroxylated benzene compounds and one or more aldehydes in the presence of one or more catalysts and water.

36. The low density open cell carbon foam of claim 34, wherein said hydroxylated benzene compound is resorcinol and said aldehyde is formaldehyde.

37. The low density open cell carbon foam of claim 34, having a meso-pore size distribution of 10 to 20 nm.

38. The low density open cell carbon foam formed by the method of claim 28.

29. A method for preparing a low density open cell carbon foam, said method comprising the steps of:

(a) forming a reaction mixture comprising one or more hydroxylated benzene compounds, one or more aldehydes, one or more catalysts, and water;

wherein the molar ratio of said hydroxylated benzene compounds to said catalysts in said reaction mixture, R/C, is greater than about 2000; and

,

(b) heating said reaction mixture at a gelation temperature for a gelation time to form an organic gel;

(c) heating said organic gel at a curing temperature for a curing time to form a cured organic gel;

(d) removing at least a portion of the water from said cured organic gel to form a low density open cell organic foam; and

,

(e) pyrolyzing said low density open cell organic foam at a pyrolysis temperature to form said low density open cell carbon foam.

30. The low density open cell carbon foam formed by the method of claim 29.

31. A method for preparing a low density open cell carbon foam/carbon substrate composite, said method comprising the steps of:

(a) forming a reaction mixture comprising one or more hydroxylated benzene compounds, one or more aldehydes, one or more catalysts, and water;

wherein the molar ratio of said hydroxylated benzene compounds to said catalysts in said reaction mixture, R/C, is greater than about 2000; and

,

(b) infusing a porous carbon substrate or a porous organic substrate with said reaction mixture to form an infused porous substrate;

(c) heating said infused porous substrate to a gelation temperature for a gelation time to form an organic gel/porous substrate composite;

(d) heating said organic gel/porous substrate composite to a curing temperature for a curing time to form a cured organic gel/porous substrate composite;

(e) removing at least a portion of the water from said cured organic gel/porous substrate composite to form a low density open cell organic foam/porous substrate composite; and

,

(f) pyrolyzing said low density open cell organic foam/porous substrate composite at a pyrolysis temperature to form said low density open cell carbon foam/carbon substrate composite.

32. The low density open cell carbon foam/carbon substrate formed by the method of claim 31.

33. The low density open cell carbon foam/carbon substrate formed by the method of claim 31 wherein the substrate has a form selected from blocks, sheets, threads, filaments, tubes, papers, membranes, felts, reticulated foams, and fabrics.

39. A method for preparing a low density open cell organic foam, said method comprising the steps of:

(a) forming a reaction mixture comprising one or more hydroxylated benzene compounds, one or more aldehydes, one or more catalysts, and water;

wherein the molar ratio of said hydroxylated benzene compounds to said catalysts in said reaction mixture, R/C, is greater than about 1000; and

,

(b) heating said reaction mixture to form an organic gel; and

,

(c) removing at least a portion of the water from said organic gel by simple evaporative drying of water, to form said low density open cell organic foam.

40. The method of claim 39 wherein, in said forming step, the weight of the hydroxylated benzene compounds and the aldehydes in the reaction mixture with respect to the total volume of the reaction mixture, R, is in the range of 30-80% w/v (weight to volume).

41. The method of claim 39 wherein said one or more hydroxylated benzene compound comprises resorcinol and said one or more aldehydes comprises formaldehyde.

42. The low density open cell organic foam formed by the method of claim 39.

43. A method for preparing a low density open cell organic foam, said method comprising the steps of:

(a) forming a reaction mixture comprising one or more hydroxylated benzene compounds, one or more aldehydes, one or more catalysts, and water;

wherein the molar ratio of said hydroxylated benzene compounds to said catalysts in said reaction mixture, R/C, is greater than about 1000; and

,

(b) heating said reaction mixture at a gelation temperature for a gelation time to form an organic gel;

(c) heating said organic gel at a curing temperature for a curing time to form a cured organic gel; and

,

(d) removing at least a portion of the water from said cured organic gel by simple evaporative drying of water, to form said low density open cell organic foam.

44. The method of claim 43 wherein, in said forming step, the weight of the hydroxylated benzene compounds and the aldehydes in the reaction mixture with respect to the total volume of the reaction mixture, R, is in the range of 30-80% w/v (weight to volume).

45. The method of claim 43 wherein said one or more hydroxylated benzene compound comprises resorcinol and said one or more aldehydes comprises formaldehyde.

46. The low density open cell organic foam formed by the method of claim 43.

47. A method for preparing a low density open cell carbon foam, said method comprising the steps of:

(a) forming a reaction mixture comprising one or more hydroxylated benzene compounds, one or more aldehydes, one or more catalysts, and water;

wherein the molar ratio of said hydroxylated benzene compounds to said catalysts in said reaction mixture, R/C, is greater than about 1000; and

,

(b) heating said reaction mixture to form an organic gel;

(c) drying said organic gel by simple evaporative drying of water, to form a low density open cell organic foam; and

,

(d) pyrolyzing said low density open cell organic foam at a high temperature to form said low density open cell carbon foam.

48. The method of claim 47 wherein, in said forming step, the weight of the hydroxylated benzene compounds and the aldehydes in the reaction mixture with respect to the total volume of the reaction mixture, R, is in the range of 30-80% w/v (weight to volume).

49. The method of claim 47 wherein said one or more hydroxylated benzene compound comprises resorcinol and said one or more aldehydes comprises formaldehyde.

50. The low density open cell carbon foam formed by the method of claim 47.

51. A method for preparing a low density open cell carbon foam, said method comprising the steps of:

(a) forming a reaction mixture comprising one or more hydroxylated benzene compounds, one or more aldehydes, one or more catalysts, and water;

wherein the molar ratio of said hydroxylated benzene compounds to said catalysts in said reaction mixture, R/C, is greater than about 1000; and

,

(b) heating said reaction mixture at a gelation temperature for a gelation time to form an organic gel;

(c) heating said organic gel at a curing temperature for a curing time to form a cured organic gel;

(d) removing at least a portion of the water from said cured organic gel by simple evaporative drying of water, to form a low density open cell organic foam; and

,

(e) pyrolyzing said low density open cell organic foam at a pyrolysis temperature to form said low density open cell carbon foam.

52. The method of claim 51 wherein, in said forming step, the weight of the hydroxylated benzene compounds and the aldehydes in the reaction mixture with respect to the total volume of the reaction mixture, R, is in the range of 30-80% w/v (weight to volume).

53. The method of claim 51 wherein said one or more hydroxylated benzene compound comprises resorcinol and said one or more aldehydes comprises formaldehyde.

54. The low density open cell carbon foam formed by the method of claim 51.

55. A method for preparing a low density open cell carbon foam/carbon substrate composite, said method comprising the steps of:

(a) forming a reaction mixture comprising one or more hydroxylated benzene compounds, one or more aldehydes, one or more catalysts, and water;

wherein the molar ratio of said hydroxylated benzene compounds to said catalysts in said reaction mixture, R/C, is greater than about 1000; and

,

(b) infusing a porous carbon substrate or a porous organic substrate with said reaction mixture to form an infused porous substrate;

(c) heating said infused porous substrate to a gelation temperature for a gelation time to form an organic gel/porous substrate composite;

(d) heating said organic gel/porous substrate composite to a curing temperature for a curing time to form a cured organic gel/porous substrate composite;

(e) removing at least a portion of the water from said cured organic gel/porous substrate composite by simple evaporative drying of water, to form a low density open cell organic foam/porous substrate composite; and

,

(f) pyrolyzing said low density open cell organic foam/porous substrate composite at a pyrolysis temperature to form said low density open cell carbon foam/carbon substrate composite.

56. The method of claim 55 wherein, in said forming step, the weight of the hydroxylated benzene compounds and the aldehydes in the reaction mixture with respect to the total volume of the reaction mixture, R, is in the range of 30-80% w/v (weight to volume).

57. The method of claim 55 wherein said one or more hydroxylated benzene compound comprises resorcinol and said one or more aldehydes comprises formaldehyde.

58. The low density open cell carbon foam/carbon substrate formed by the method of claim 55.

59. The low density open cell carbon foam/carbon substrate formed by the method of claim 55 wherein the substrate has a form selected from blocks, sheets, threads, filaments, tubes, papers, membranes, felts, reticulated foams, and fabrics.

60. A low density open cell organic foam characterized by a density of 300 to 900 mg/cm³, a surface area of 200 to 1000 m² /g, and a meso-pore size distribution of 5 to 50 nm.

61. The low density open cell organic foam of claim 60, wherein said low density open cell organic foam is formed by at least partial evaporative removal of water from an organic gel, said organic gel formed by the reaction of one or more hydroxylated benzene compounds and one or more aldehydes in the presence of one or more catalysts and water.

62. The low density open cell organic foam of claim 60, wherein said low density open cell organic foam wherein the meso-pore size distribution is from about 10 to about 50 nm.

63. The low density open cell organic foam of claim 60, wherein said low density open cell organic foam wherein the meso-pore size distribution is from about 10 to about 25 nm.

64. The low density open cell organic foam of claim 60, wherein said low density open cell organic foam is colored orange to deep red.

65. A low density open cell carbon foam characterized by a density of 300 to 900 mg/cm³, a surface area of 200 to 800 m² /g, a meso-pore size distribution of 5 to 50 nm, and an electrical capacitance of 10 to 80 F/g.

66. The low density open cell carbon foam of claim 65, wherein said low density open cell carbon foam is formed by pyrolysis of a low density open cell organic foam, said low density open cell organic foam formed by at least partial evaporative removal of water from an organic gel, said organic gel formed by the reaction of one or more hydroxylated benzene compounds and one or more aldehydes in the presence of one or more catalysts and water.

67. The low density open cell carbon foam of claim 65, wherein said hydroxylated benzene compound is resorcinol and said aldehyde is formaldehyde.

68. The low density open cell carbon foam of claim 65, having a meso-pore size distribution of 10 to 20 nm.