Surface-treatment chemistry in the manufacture of aerogels: computational modelling of cyclic and linear siloxanes

Theoretical study on the dimerization of Si(OH)4 in aqueous solution and its dependence on temperature and dielectric constant

“…It is also of interest in materials science because of its importance in sol-gel synthesis of zeolites and other silicates and aluminosilicates. A number of theoretical studies in the chemistry and materials science literature have considered this reaction either in passing (Johnson et al, 1989;Field and Olson, 2001;Ignatov et al, 2003;van Duin et al, 2003) or in considerable detail (Kudo and Gordon, 1998;Cypryk and Apeloig, 2002;Catlow et al, 2003). In the studies of Kudo and Gordon (1998) and Cypryk and Apeloig (2002) the focus has been not on the energetics of the reactants and products but on the activation energy for the reaction and in some cases its dependence upon the participation of water.…”

Comparative studies on the surface chemical modification of silica aerogels based on various organosilane compounds of the type RnSiX4−n

“…However, the organochlorosilane-derivatized TEOS aerogels are less transparent due to the internal cracking of the network during the derivatization process. This cracking can be a result of the heat produced and released during the formation of HCl [26,27] that occurs when organochlorosilanes are used to derivatize the alcogels.…”

Reactive modeling of the initial stages of alkoxysilane polycondensation: effects of precursor molecule structure and solution composition

“…Over the course of the simulation, the average size of siloxane rings increases. Two-membered rings have excess strain 54 from the O-Si-O and Si-O-Si angles. The average size of siloxane rings increases over time as additional monomers are available to form rings.…”