Characterization and Modification of Carbon Material Surface

Abstract

Characterization of carbon surface has been investigated by spectroscopic methods includingX-ray photoelectron spectroscopy, laser Raman spectroscopy, and FT-IR attenuated totalreflection technique. Changes of the surface with oxidation have been clarified from theview point of surface graphitic structure and oxygen-containing functional groups. The speciesof surface functional groups formed by the oxidation are closely responsible for the surfacegraphitic structure in character. The electrochemical treatments with ammonium hydrogencarbonate, sulfuric acid, and tetraethylammonium hydroxide solutions are tested. The addition ofcarboxyl groups is accompanied by the destruction of the surface graphitic structure. For theammonium hydrogencarbonate electrolyte, the surface is able to be modified through the gradualdestruction of the graphitic structure. Oxygen plasma treatment removes less ordered structurepresent on the edge surface. As a result, keto-enol structure is added to the surface. Hydroxylgroups added to the edge surface play an important role in improving the adhesion betweenthe edge surface and epoxy resin. On the other hand, PVC would interact with functionalgroups containing a>C=O group present on the edge surface. Information obtained from thisstudy can be applied to modify and control interfacial region in carbon fiber reinforced composites.