US 11,654,409 B2
Methods for fabrication of silica aerogels with custom shapes using freeze drying
Massimo Bertino, Glen Allen, VA (US); Lauren White, Henrico, VA (US); Dalton Echard, Fairfax, VA (US); and Tyler Selden, Richmond, VA (US)
Assigned to Virginia Commonwealth University, Richmond, VA (US)
Filed by VIRGINIA COMMONWEALTH UNIVERSITY, Richmond, VA (US); and QATAR FOUNDATION FOR EDUCATION, SCIENCE AND COMMUNITY DEVELOPMENT, Education (QA)
Filed on Jul. 27, 2020, as Appl. No. 16/939,769.
Application 16/939,769 is a continuation of application No. 16/095,158, abandoned, previously published as PCT/US2017/028903, filed on Apr. 21, 2017.
Application 16/095,158 is a continuation in part of application No. 15/500,376, filed on Jan. 30, 2017, granted, now 10,414,894, issued on Sep. 17, 2019.
Claims priority of provisional application 62/325,525, filed on Apr. 21, 2016.
Prior Publication US 2020/0353437 A1, Nov. 12, 2020
Int. Cl. B01J 13/00 (2006.01); C08J 3/075 (2006.01); C01B 33/158 (2006.01); C08G 77/388 (2006.01)
CPC B01J 13/0091 (2013.01) [C01B 33/1585 (2013.01); C08G 77/388 (2013.01); C08J 3/075 (2013.01); C01P 2006/60 (2013.01); C08J 2205/026 (2013.01); C08J 2333/02 (2013.01); C08J 2383/04 (2013.01); C08J 2383/08 (2013.01)] 19 Claims
 
1. A method for producing an aerogel, comprising:
combining a silicon alkoxide or an alkoxide of other transition metals, an acrylate or acrylated monomer and/or an di-isocyanate or tri-isocyanate monomer, a silica derivatizer for derivatizing the resulting pores, the silica derivatizer being an organosilane carrying a polymerizable moiety, a polymerization initiator, being a thermal initiator or a photoinitiator, a solvent, and a catalyst, the catalyst being an acid, a base or a catalyst containing fluoride, as a composition;
pouring the composition into a mold;
allowing the composition to form a wet gel by way of hydrolysis of the alkoxide and condensation of the hydrolyzed alkoxide, the gelation being catalysed by the catalyst;
removing solvents from the wet gel; then
exposing the wet gel to a light or heat stimulus with sufficient intensity to catalyze cross-linking of the wet gel by the polymerization initiator; and
freeze drying the cross-linked wet gel to form an aerogel,
wherein said removing solvent steps increases transparency of the aerogel compared to process where removing solvents is not performed.