Modifications produced by O-2 and CO2 plasma treatments on a glassy carbon: comparison with molecular gases

A carbon material obtained by pyrolysis of polyfurfuryl alcohol was submitt ed to four different treatments. Two of these were carried out using molecu lar gases (oxygen and carbon dioxide) and two using plasma of the same mole cules. The textural and chemical modifications produced by these treatments were studied by N-2 and CO2 adsorption at 77 and 273 K, respectively, merc ury porosimetry and Fourier Transformed Infrared Spectroscopy (FTIR). In ad dition, the changes in the external surface produced by the treatments were observed by Scanning Electron Microscopy (SEM). Molecular carbon dioxide t reatment opens and creates microporosity. However, plasma treatments mainly produce constrictions at the entrance of the micropores. The effect of the molecular treatments on the external surface is not easily observed, while plasmas treatments produce pits on the surface. The statistical analysis o f these have been obtained in order to establish their evolution. (C) 1999 Elsevier Science Ltd. All rights reserved.