Carbon—Silica Dual Phase Filler: Part III. ESCA and IR Characterization

Abstract

Abstract A series of carbon—silica dual phase fillers have been analyzed using electron spectroscopy for chemical analysis (ESCA) and infrared spectroscopy (IR). These techniques reveal that the silicon in these materials is consistent with that in silica, and the predominant carbon in the carbon phase is similar to the predominant carbon in carbon black. ESCA and IR experiments demonstrate that the carbon—silica dual phase fillers are comprised of composite aggregates, each containing carbon and silica phases. In these dual phase aggregates the silica phase is intimately distributed with the carbon phase. Quantitative ESCA reveals that these dual phase fillers have excess oxygen over the expected stoichiometric amount for the silica present. This excess oxygen is likely due to oxygen groups on the carbon phase. Analysis of the ESCA oxygen Auger lines in combination with various chemical treatments substantiate the presence of carbon phase oxygen groups on the dual phase fillers. Quantitative ESCA in combination with IR spectra of a dual phase filler after removal of the silica phase, by HF treatment, suggests that the carbon phase of the dual phase filler contains more oxygen groups than its carbon black counterpart.