Observation of plasma-treated carbon black surfaces by scanning tunnelling microscopy

Abstract The graphitized carbon black N550G was treated in different atmospheric plasmas, such as air, ammonia, argon, and hydrogen. The plasma-treated surfaces were investigated by scanning tunnelling microscopy (STM) until atomic resolution. The surface chemical properties of these carbon blacks were characterized by electron spectroscopy (ESCA). It was found that air, ammonia, and argon plasmas result in a destruction of graphitic structure of graphitized carbon black surfaces. Chemical modification of the surface also takes place in air and ammonia plasma treatment. The hydrogen plasma, however, has only a little effect on the black surface. The surface energy of carbon blacks, measured by inverse gas chromatography, shows a good correlation with the defects of graphitic basal planes.