Structural models of dense aerogels

The cluster model: A hierarchically-ordered assemblage of random-packing spheres for modelling microstructure of porous materials

“…The structure of aerogels has been described as an assembly of randomly-packed spherical particles in several hierarchically-ordered levels [4][5][6][7]. Knowledge of the aerogel structure has been acquired using computer simulation techniques taking inputs from several sources, such as the understanding of the sol-gel process, and the relationship between the structure and the mechanical properties.…”

Bioactive organic-inorganic hybrid aerogels

“…The homogeneous liquids were poured in glass hermetic containers at 50°C until gelation. Supercritical drying was performed in autoclave with ethanol (T = 260ºC, P = 90 bar) following the procedure already described [1].…”

Structure of bioactive mixed polymer/colloid aerogels

“…The homogeneous liquids were poured in glass hermetic containers at 50°C until gelation. Supercritical drying [20] was performed in autoclave (T = 260°C, P = 90 bar) following the procedure already described [21]. There were also prepared two counterparts of the sample containing 30% weight of colloid particle adding the amount necessary of Ca(NO 3 ) 2 to have a final product containing 3% weight of Ca, the difference between them is the ultrasound dose applied.…”

“…We have simulated the structure of dense gels by random close packing (RCP) models [13] from which some information about the microstructure of the gel can be obtained by using theses models [14]. Applying RCP structural models the existence of several typical sizes is manifested, whereas the USAXS (ultra small X-ray scattering) tests [15] shows a hierarchy-ordered structure.…”

“…Applying RCP structural models the existence of several typical sizes is manifested, whereas the USAXS (ultra small X-ray scattering) tests [15] shows a hierarchy-ordered structure. In this paper this structural approach, thoroughly described in former papers [2,16,17], has been applied.…”