Aerogels, definition

Adsorptive properties of porous silicas compacts of pyrogenic powders, 506, 507f precipitated silicas, 507-509 silica gels, 509, 510-512 zeolitic silicas, 512-514 Adsorptive properties of silicas, challenges for improvement, 505 Aerogel(s) definition, 7, 620 porosities, 379, 380 ... 

CAS 63231-67-4 977052-02-0 EINECS/ELINCS 231-545-4 Synonyms Metasilicic acid Silica aerogel Definition A regenerative adsorbent consisting of coherenL continuous three-dimensional network of spherical particles of colloidal silica Empirical OiSi Formula SiOj... 

The Table 5.4 data suggest that the density and volume shrinkage of the aerogels increase and the porosity decreases in the following order of alcohols used isopropanol < methanol < ethanol < propanol < isobutanol < butanol < hexanol. Isopropanol and methanol definitely produce the best aerogels. The chain length of the hydrocarbon end... 

For untreated aerogels that possess by definition a well-accessible pore network, the volume determined corresponds to the specific volume of the aerogel backbone, i.e., the inverse of the aerogel backbone density this is an important figure for the calculation of the... 

There is disagreement within the aerogel community about the definitions of aerogel materials. Some definitions include porosity restrictions such as mesoporosity requirements (2-20 nm), others require supercritical drying techniques, and some include density restrictions. Even measuring these properties can lead to uncertainties and controversy. 

The definite, undisputed applications of aerogels remain in Cherenkov radiation detectors, thermal insulation and in space exploration. But, as evidenced by this Aerogels Handbook, it is expected to be a short matter of time before the concerted efforts of industry, academia and government lead to the wide use of those remarkable materials in construction, transportation, health care and the National Defense. 

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