n-hexadecyltrimethylammonium chloride (CTAC): 100 g
tri-functional alkoxysilane: 2.1 mol
di-functional alkoxysilane: 1.4 mol
Process
Mixing alkoxysilanes, urea, and CTAC in a dilute aqueous acetic acid solution in closed container, and stirring for 60 min at RT to promote hydrolysis.
Transferring the container to an oven for gelation and aging at 80 °C over 6 hours.
Washing with methanol.
Evaporative drying under ambient conditions.
Reference
Hayase, G.; Kanamori, K.; Nakanishi, K. New Flexible Aerogels and Xerogels Derived from Methyltrimethoxysilane/dimethyldimethoxysilane Co-Precursors. J. Mater. Chem.2011, 21, 17077–17079. doi:10.1039/C1JM13664J