Influence of solution pH, supporting electrolyte presence and solid content on the stability of aqueous nanosilica suspension

The effects of solution pH, supporting electrolyte presence and solid content on nanosilica suspension stability were examined. The turbidimetry method was applied to monitor the changes in the system stability in the short (about 2 h) and long (about 18 days) periods of time. The stability coefficients and aggregate diameters were calculated numerically to estimate colloidal system properties. The sodium chloride presence (as a supporting electrolyte) improves the stability conditions of SiO2 suspension. The greatest effect of solution pH change is observed in the aqueous medium. The most unstable system occurs at pH 10.6 after 18 days.