Electrolyte-induced destabilization of hydrosols containing uniform TiO2 nanoparticles

Abstract

The electrolyte-induced destabilization of TiO2 hydrosols consisting of anatase nanocrystals with a narrow particle size distribution is studied. It is established that, on the addition of HCl and KCl, the sols can undergo both fast and slow structural changes. It is shown that the thresholds of fast coagulation increase considerably as the nanoparticle size diminishes. The reversibility and probable mechanisms of the slow structural changes, whose rate drastically increase with the electrolyte concentration, are discussed. The obtained results make it possible to improve the method for fractionation of TiO2 sols based on coagulation with electrolytes.