SCANNING-TUNNELING-MICROSCOPY OF CARBON-BLACKS

Three kinds of carbon black, HAF (high abrasion furnace, N330), MT (me dium thermal, N990), and graphitized MT were observed with the scannin g tunneling microscope (STM), the transmission electron microscope (TE M), and the scanning electron microscope (SEM). All the STM images are formed from measurements of the x, y, and z position of points on the surface of the particle. The STM images of carbon blacks were compare d to transmission electron microscope (TEM) photographs. Pitted and st epped bumps were observed on the surface of HAF carbon black. The surf ace of MT carbon black was more rough and disorganized. At the atomic scale, ordered structure was found on the surface of HAF carbon-black particles. Graphitized MT carbon-black particles were faceted polyhedr a. Some facets were smooth while others had multiple terraces. The sur face of graphitized MT carbon black was so well ordered that a lattice of carbon atoms similar to HOPG (highly ordered pyrolytic graphite) w as observed on the smooth facets.