FILLER-ELASTOMER INTERACTIONS .11. INVESTIGATION OF THE CARBON-BLACK SURFACE BY SCANNING-TUNNELING-MICROSCOPY

Scanning tunneling microscopy (STM) has recently been demonstrated to be a powerful and versatile tool to image the microstructure of the surface of carbonaceous materials. In this study, the surfaces of carbon blacks, both graphitized and nongraphitized, were investigated with this technique. The STM images show that the carbon-black surface can be classified into two domains, an organized and an unorganized one. The degree of carbon atom organization varies with the carbon-black grade and increases drastically upon graphitization. The surface energies and energy distributions of graphitized and nongraphitized carbon blacks, measured by inverse gas chromatography, correlate well with their surface microstructure. Mapping of the carbon-black topography showed that although the surface is not smooth, there is no significant porosity either.