Ceramics-Silikáty 48 (2) 72-75 (2004)

A GELATION PROCESS IN SiO₂ - H₂O SYSTEM IN THE PRESENCE OF CALCIUM ACETATE MONOHYDRATE

N. Fasurová, J. Havlica

A sol of silicon dioxide has been used for modeling of the interactions of calcium salt with SiO₂ - H₂O in high dispersive system. The dependence of the zeta potential on concentration of calcium acetate in SiO₂ - H₂O system has been characterized at lower concentration of acetate by negative values. Isoelectric point has been determined at ratio molar concentration of acetate to silicon dioxide r = ccalciumacetate/cSiO₂ = 0.347. This work is focused on determination of optimum conditions for gelation, control of sol stability and explaining of gelation mechanism by ion exchange on silica surface.

Keywords: Sol SiO₂, Hydrosilicate gel, Zeta potential, Isoelectric point