RT journal article
T1 Facile preparation of mesoporous silica monoliths by an inverse micelle mechanism
A1 Facio, Dario S.
A1 Luna Aguilera, Manuel Jesús
A1 Mosquera Díaz, María Jesús
A2 Química Física
K1 Inverse micelles
K1 Formation and growth model
K1 Silica monoliths
K1 Surfactant
K1 Cracking-free
K1 Mesoporosity
AB A well-known drawback of solegel materials is their tendency to crack because of the high capillarypressure supported during drying. We have pioneered a facile and low-cost route to obtain monolithicxerogels, from a silica precursor and a surfactant, mixed under ultrasonic agitation. This route presents a clear interest for practical application at industrial scale. In this paper, a model to explain the formation of silica monoliths in the presence of the surfactant is presented. It is demonstrated that a stable microemulsion of water in the silica oligomer media is produced due to the combined effect of surfactant, producing inverse micelles, and ultrasonic agitation. The model proposed, suggests that the water is encapsulated in the surfactant micelles that act as nanoreactors, producing silica primary particles. The growth of these silica seeds continues outside the micelles until the formation of the constituent particles of the xerogel. Next, the particles are packed, and mesopores are produced from the interparticle spaces. This mesoporosity prevents xerogel cracking because it reduces capillary pressure during gel drying. An in-depth investigation of the structure of the xerogels revealed that they are effectively composed of silica nanoparticles of nearly uniform size values that could match with the size of the surfactant inverse micelles. Finally, it was demonstrated that surfactant and water content present a significant effect on the final structure of the xerogels. An increase of surfactant content produces a reduction in particle size, whereas an increase of water produces an opposite effect.
PB Elsevier
SN 1387-1811
YR 2017
FD 2017-03
LK http://hdl.handle.net/10498/38631
UL http://hdl.handle.net/10498/38631
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 09-nov-2026