Aerogels, emulsions, and composites: Controlling structure with organic sol-gel chemistry
The sol-gel polymerization of resorcinol with formaldehyde is a proven synthetic route for the formation of organic aerogels. These materials can also be pyrolyzed in an inert atmosphere to form vitreous carbon aerogels. Both resorcinol-formaldehyde and carbon aerogels are characterized by high porosity (50--98%), ultrafine cell/pore sizes (< 100 mn), high surface area (400--1000 m{sup 2}/g), and a solid matrix composed of interconnected colloidal-like particles or fibrous chains with characteristic diameters of 10 nm. While this nanostructure and the low Z (atomic number) composition are responsible for the unique optical, thermal, acoustic, mechanical, and electrical properties of organic aerogels, there are certain applications in which a larger scale structure is also desired in combination with the unique features of the aerogel. In order to achieve this goal, we have been emulsifying our resorcinol-formaldehyde sols to form foams which retain the aerogel framework but have some cells/pores as large as 2 {mu}m. In another approach, we have infused an emulsion-derived polystryene foam with a resorcinol-formaldehyde sol to form a new composite foam. This paper addresses the chemistry-structure-property relationships of organic aerogels, their emulsion-derived derivatives, and composite foams.
- Research Organization:
- Lawrence Livermore National Lab., CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 10172641
- Report Number(s):
- UCRL-JC-109956; CONF-921110-25; ON: DE92019575
- Resource Relation:
- Conference: Winter annual meeting of the American Society of Mechanical Engineers (ASME),Anaheim, CA (United States),8-13 Nov 1992; Other Information: PBD: Apr 1992
- Country of Publication:
- United States
- Language:
- English
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