Low density, resorcinol-formaldehyde aerogels

Claim 2

A process for the synthesis of a low density, organic aerogel of ultra-fine pore size, said process comprising the steps of: mixing in a predetermined ratio a polyhydroxy benzene and formaldehyde in the presence of a base catalyst; heating the mixture to a predetermined temperature for a sufficiently long period of time to form a stable gel; washing the gel in a suitable organic solvent to exchange the aqueous solvent for the organic solvent; critical point drying the gel; and characterizing the gel.

Claim 3

The process of claim 1, wherein the pH of said mixture is in the range of about 6.5 to about 7.4.

Claim 4

The process of claim 2, wherein the polyhydroxy benzene is a dihydroxy benzene.

Claim 5

The process of claim 3, wherein said dihydroxy benzene is selected from the group consisting of resorcinol, catechol, substituted resorcinol, substituted catechol and mixtures thereof.

Claim 6

The process of claim 4, wherein said dihydroxy benzene is resorcinol.

Claim 7

The process of claim 5, wherein said solvent is selected from the group consisting of methanol, acetone, isopropanol and amyl acetate.

Claim 8

The process of claim 6, wherein said solvent is acetone.

Claim 9

The process of claim 7, wherein the ratio of said resorcinol to said formaldehyde is about 1:2.

Claim 10

The process of claim 8, wherein said base catalyst is sodium carbonate.

Claim 11

The process of claim 9, further comprising the step of heating said aerogel in a nitrogen atmosphere, to a temperature in the range of about 600° to about 1200° C. to carbonize said aerogel and form a low density, carbon foam.

Claim 12

The process of claim 4, wherein said dihydroxy benzene is a mixture of resorcinol and catechol.

Claim 13

The process of claim 4, wherein said dihydroxy benzene is a mixture of resorcinol and hydroquinone.

Claim 14

The process of claim 4, wherein said dihydroxy benzene is a mixture of resorcinol and phloroglucinol.

Claim 15

A process for the synthesis of a low density, microcellular resorcinol-formaldehyde aerogel, said process comprising the steps of: (a) mixing resorcinol and formaldehyde in a molar ratio of about 1:2, in the presence of catalytic amounts of sodium carbonate; (b) adjusting the pH of the mixture to a value in the range of about 6.5 to about 7.4; (c) decanting the mixture into a glass ampoule; (d) sealing the glass ampoule; (e) heating the mixture to about 85° C. in an oven for about seven days to facilitate formation of a gel; (f) removing the ampoule from the oven and cooling it to room temperature; (g) breaking the ampoule and removing the gel from the ampoule; (h) washing the gel in an agitated bath of trifluoracetic acid at 45° C. for three days; (i) transferring the gel from the acid bath to an agitated acetone bath maintained at about 45° C., to remove water; (j) removing the gel from the acetone bath and critical point drying the gel; and (k) characterizing the gel.

Claim 16

A process for the synthesis of a low density, microcellular resorcinol-formaldehyde aerogel, said process comprising the steps of: (a) mixing resorcinol and formaldehyde in a molar ratio of about 1:2, in the presence of catalytic amounts of sodium carbonate; (b) adjusting the pH of the mixture to a value in the range of about 6.5 to about 7.4; (c) decanting the mixture into a glass ampoule; (d) sealing the glass ampoule; (e) heating the mixture to about 85° C. in an oven for about seven days to facilitate formation of a gel; (f) removing the ampoule from the oven and cooling it to room temperature; (g) breaking the ampoule and removing the gel from the ampoule; (h) washing the gel in an agitated bath of trifluoracetic acid at 45° C. for three days; (i) transferring the gel from the acid bath to an agitated acetone bath maintained at about 45° C., to remove water; (j) removing the gel from the acetone bath and critical point drying the gel; and (k) characterizing the gel.

Claim 17

The process of claim 14, further comprising the step of heating said aerogel in a nitrogen atmosphere to a temperature in the range of about 600° to about 1200° C. to carbonize said aerogel and form a low density, carbon foam.