Influence of synthesis conditions and thermal treatment on the properties of hydrated silica

Abstract

The influence of synthesis conditions (solvent, rate and order of reagents mixing, precipitation
pH and ultrasonic treatment) and heat treatment on the properties, particles size and morphology of
hydrated silica had been investigated. It was shown that the particles size is much more influenced by the
rate of reagents mixing, rather than the precipitation pH. Heat treatment increases the specific surface area
of SiO2. The minimum particle size (5-10 nm) and maximum specific surface area (up to 800m2/g) were
obtained for silica precipitated at pH = 6