Organic, open cell foam materials, their carbonized derivatives, and methods for producing same
View Patent ↗Organic, small pore area materials (“SPMs”) are provided comprising open cell foams in unlimited sizes and shapes. These SPMs exhibit minimal shrinkage and cracking. Processes for preparing SPMs are also provided that do not require supercritical extraction. These processes comprise sol-gel polymerization of a hydroxylated aromatic in the presence of at least one suitable electrophilic linking agent and at least one suitable solvent capable of strengthening the sol-gel. Also disclosed are the carbonized derivatives of the organic SPMs.
1. A method for preparing an organic, small pore area material, said method comprising the steps of:
(a) forming a solution comprising a hydroxylated aromatic, an electrophilic linking agent, and a carboxylic acid;
(b) allowing said solution to form a sol-gel; and,
(c) removing substantially all of the fluid portion of said sol-gel.
2. The method of claim 1 , wherein the solution formed in step (a) further comprises a catalyzing agent.
3. The method of claim 2 , wherein said catalyzing agent is independently selected from the group consisting of hydrochloric acid, sulfuric acid and hydrobromic acid.
4. The method of claim 1 , wherein step (b) includes the substep of subjecting said solution to either: (i) a temperature or a pressure higher than ambient; or (ii) a temperature and a pressure higher than ambient.
5. The method of claim 1 , wherein step (c) includes the substep of evaporating said fluid portion at ambient conditions.
6. The method of claim 1 , further including the substep of subjecting said fluid portion to either: (i) higher than ambient temperatures or lower than ambient pressures; or (ii) higher than ambient temperatures and lower than ambient pressures.
7. The method of claim 1 , wherein step (c) is substantially accomplished by subjecting said sol-gel to centrifugation.
8. The method of claim 1 , wherein step (c) is substantially accomplished by subjecting said sol-gel to freeze drying.
9. The method of claim 1 , wherein step (c) is substantially accomplished by subjecting said sol-gel to a gas pressure differential across said sol-gel.
10. The method of claim 1 , wherein step (c) is substantially accomplished by supercritical extraction of said sol-gel.
11. The method of claim 1 , further comprising the step (d) of pyrolizing said low density microcellular material at a pyrolysis temperature to form a carbonized derivative of said low density microcellular material.
12. A method for preparing an organic, low density microcellular material, said method comprising the steps of:
(a) forming a solution comprising a hydroxylated aromatic, an electrophilic linking agent, and a carboxylic acid;
(b) allowing said solution to form a sol-gel; and,
(c) removing substantially all of the fluid portion of said sol-gel.
13. The method of claim 12 , wherein the solution formed in step (a) further comprises a catalyzing agent.
14. The method of claim 13 , wherein said catalyzing agent is independently selected from the group consisting of hydrochloric acid, sulfuric acid and hydrobromic acid.
15. The method of claim 12 , wherein step (b) includes the substep of subjecting said solution to either: (i) a temperature or a pressure higher than ambient; or (ii) a temperature and a pressure higher than ambient.
16. The method of claim 12 , wherein step (c) includes the substep of evaporating said fluid portion at ambient conditions.
17. The method of claim 12 , further including the substep of subjecting said fluid portion to either: (i) higher than ambient temperatures or lower than ambient pressures; or (ii) higher than ambient temperatures and lower than ambient pressures.
18. The method of claim 12 , wherein step (c) is substantially accomplished by subjecting said sol-gel to centrifugation.
19. The method of claim 12 , wherein step (c) is substantially accomplished by subjecting said sol-gel to freeze drying.
20. The method of claim 12 , wherein step (c) is substantially accomplished by subjecting said sol-gel to a gas pressure differential across said sol-gel.
21. The method of claim 12 , wherein step (c) is substantially accomplished by supercritical extraction of said sol-gel.
22. The method of claim 12 , further comprising the step (d) of pyrolizing said low density microcellular material at a pyrolysis temperature to form a carbonized derivative of said low density microcellular material.
23. The method of claim 1 or 12 , wherein said hydroxylated aromatic comprises a hydroxylated benzene compound.
24. The method of claim 1 or 12 , wherein said hydroxylated aromatic comprises a phenolic novolak compound.
25. The method of claim 1 or 12 , wherein said electrophilic linking agent comprises an aldehyde.
26. The method of claim 1 or 12 , wherein said electrophilic linking agent comprises furfural.
27. The method of claim 1 or 12 , wherein said carboxylic acid comprises acetic acid, formic acid, propionic acid, butyric acid, pentanoic acid or an isomer thereof.
28. The method of claim 1 or 12 , wherein said carboxylic acid comprises acetic acid.