Effect of silane coupling agents on properties of precipitated sodium–aluminium silicates

Sodium–aluminium silicates of highly dispersion degree were obtained. Studies on the surface modification of sodium–aluminium silicates using silane coupling agents are described. The best modifiers were selected, which induced a change of the silicate surface from a hydrophilic to a hydrophobic one. Physicochemical analyses of the obtained silicates were performed. The methods of evaluating the degree of surface modification of the silicate were presented. Near infrared spectroscopy was used to determine the degree of condensation of the silicate surface silanol groups. The degree of hydrophobization of silicate surface was determined by a calorimetric method. Studies on morphology and microstructure using transmission electron microscopy were performed. Moreover, particle size and tendency to form primary and secondary agglomerate structures were determined.