STRUCTURAL PECULIARITIES OF THE AGGREGATE D PARTICLES OF POLYSILICIC ACID IN POLAR AND NONPOLAR MEDIA

Wide-angle light scattering was used to study structural peculiarities of the aggregates of particles of polysilicic acid (Ultrasil VN-3, Ze osil 160, Zeosil 240, and Percosil KS404) in polar (distilled water) a nd nonpolar (toluene) media. It was shown that the aggregates are frac tal objects, and their structure is described by fractal dimension. Fo r small size scales (L < 120 nm), the fractal dimension D is smaller t hen for large size scales (D = 1.6 - 1.9 and 2.1 - 2.36, respectively) and depends on the particle type and the polarity of the dispersion m edium. Based on the results of the measurements we performed, we discu ss the reinforcing abilities of polymers of silicic acid commercially used as rubber fillers.