On the Surface Oxidation of Carbon

Abstract

Carbon powder baked from phenol-formaldehyde resin at 1200°C, was oxidized in air between 200-900°C. Contact resistance, alkali, humidity and methylene-blue adsorptions show maxima at 500-500°C. By thermal decomposition of the oxidized carbon, humidity and methyleneblue adsorptions do not change, but on the other hand, contact resistance and alkali adsorption diminish, followed by the gas evolution, thereby some functional relation exists among them. From these, the resistance increase by oxidation may be regarded as mainly due to the surface oxide formation.