title: Ion-specific effect on the gelation kinetics of concentrated colloidal silica suspensions.
abstract: The comparative gelation kinetics of concentrated colloidal silica suspensions at pH 9.8 has been studied in the presence of two different counterions, ammonium as a representative structure-breaker ion and sodium as a representative structure-maker ion. For the same ionic strength of 0.45 M, the experimental results have indicated a pronounced effect of the ion-specificity on the aggregation kinetics and on the microstructure of the gelified networks at the sol-gel transition. This was ascribed to the significant difference of the critical coagulation concentration value in the presence of the two electrolytes.
authors.affiliation: Laboratoire de Génie Chimique, UMR 5503, Université Paul Sabatier, 118, route de Narbonne, 31062 Toulouse, Cedex, France. jeanluc.trompette@ensiacet.fr
authors.forename: J L
authors.initials: JL
authors.lastname: Trompette
authors.forename: M
authors.initials: M
authors.lastname: Meireles