A Survey of Complementary Methods for the Characterization of Dense Colloidal Silica

Abstract

The aim of this study is to enhance existing knowledge for using different techniques developed for characterization of stability and particle sizing of nanoparticles in dense dispersions subjected to interparticular and hydrodynamic forces. Silica suspension, commercially known as Klebosol® 30R50 and containing particle size 80 nm on average, was investigated in the study over a wide range of concentrations. The investigations were carried out using different optical and acoustic techniques such as laser diffraction, multiple light scattering, photon correlation spectroscopy and acoustic spectroscopy. The study brings out capabilities and limitations of these modern techniques based on different physical principles behind the characterization of size distribution of particles in suspensions. The results are presented in terms of particle size range, solid concentration and technological aspects such as on-line and off-line analysis. An important finding is that at higher concentrations many of these modern techniques need to be improved because the standard models become practically invalid because of complex interaction of acoustic and optical waves with particles in suspensions of silica.