The Modification of Silica Aerogel Materials for Contemporary Use

Aerogel materials have had limited utility due to their fragility, geometrical limitations, fabrication costs and protracted fabrication times. The objective of this project was to eliminate these limitations. Native, cross-linked and hybrid aerogel monoliths have been fabricated using a newly developed one-pot method without the need for solvent exchange. The key to this technique is the use of an ethanol–water azeotrope mixture, which contains 4.4% water by volume, as both a gelation and supercritical drying solvent. The small water content allows for drying at temperatures close to the supercritical temperature of the dry solvent, where reactions such as silica dissolution and polymer degradation are negligible. This improvement on conventional fabrication processes is of particular importance since it decreases the total duration of aerogel fabrication from five days to one day. Cross-linked silica aerogel monoliths were fabricated using one-pot hydrolysis-condensation wet chemistry methods as well as a rapid photogelation method. Both native silica and cross-linked aerogel components were made with a minimum dimension of up to 3.6 cm and in customizable shapes. Fabrication of homogeneous aerogels using these methods required a maximum of one day, as demonstrated in this work. Finally, LEDs and Laser irradiation were both used to selectively embed cross-linked aerogel into a larger native silica component to provide reinforcement and/or a surface which can be used for labeling or affixing the aerogel component to another surface