Influence of ionic specificity on the microstructure and the strength of gelled colloidal silica suspensions.
The dynamic rheological behavior of gelled Ludox suspensions in the presence of the structure-breaker ammonium counterion and the structure-maker sodium counterion has been investigated. Depending on the nature of the electrolyte and its concentration, the results highlight the crucial effect of the network microstructure on the rheological results. Within the same microstructure, the strength of gelled networks has been found to be greater in the presence of the poorly hydrated ammonium counterions at any Ludox volume fraction. The obtained results were discussed with respect to recent contradictory trends reported in the literature concerning the behavior of silica suspensions.
Laboratoire de Génie Chimique UMR 5503, Université Paul Sabatier, 118, route de Narbonne, Toulouse 31062 Cedex, France. jeanluc.trompette@ensiacet.fr
J L
JL
Trompette
M J
MJ
Clifton