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The choice of sol-gel precursors, polymerization catalyst, and
reaction solvent can each be used to control the microstructure of the
resultant gel. As an example, the amount and type of polymerization
growth, and interconnectivity of the primary particles that comprise
the aerogel framework.
In the case of base-catalyzed RF aerogels, the size and number of
polymer clusters formed during polymerization is controlled by the
molar ratio of resorcinol to catalyst (R/C ratio) used in the reaction.
Formulations that utilize high R/C ratios (R/C ≥ 500) typically
produce gels ...