New organic aerogels based upon a phenolic-furfural reaction

• Published in: Journal of non-crystalline solids Vol. 188; no. 1; pp. 34 - 40
• Main Authors: Pekala, R.W, Alviso, C.T, Lu, X, Gross, J, Fricke, J
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01-07-1995; Elsevier
• Subjects: Chemistry; Colloidal gels. Colloidal sols; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Elastic modulus; Particle size; Furfural; Aerogel; Polymerization; Alcohol; Experimental study; Phenolic resin; Characterization; Colloidal gel; Transmission electron microscopy; Preparation; Crosslinked polymer; Thermal conductivity; Surface area; Structural analysis
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/0022-3093(95)00027-5

The aqueous polycondensation of (1) resorcinol with formaldehyde and (2) melamine with formaldehyde are two proven synthetic routes for the formation of organic aerogels. A new type of organic aerogel based upon a phenolic-furfural (PF) reaction was recently discovered. This solgel polymerization has a major advantage over past approaches since it can be conducted in alcohol (e.g., 1-propanol), thereby eliminating the need for a solvent exchange step prior to supercritical drying from carbon dioxide. The resultant aerogels are dark brown in color and can be converted to a carbonized version upon pyrolysis in an inert atmosphere. Brunauer-Emmett-Teller (BET) surface areas of 350–600 m
2/g have been measured, and transmission electron microscopy reveals an interconnected structure of irregularly shaped particles or platelets with ∼ 10 nm dimensions. Thermal conductivities as low as 0.015 W/m K have been recorded for PF aerogels under ambient conditions. Chemistry and structure-property relationships of these new materials are described.