Synthesis, formation and characterization of micron-sized glassy carbon spheres of controlled pore structure

Abstract

A method of producing uniform-sized solid or hollow glassy carbon spheres with sizes from a few to 200 μm in times from seconds to minutes has been developed. The spheres are obtained by atomizing polymers of furfuryl alcohol containing pore forming agents in the form of either dissolved high boiling organics or dispersed carbon black. These agents were added to control the porosity, the pore size distribution and the surface areas of the chars. Heat treatment and/or partial oxidation in the range of 800 to 1600 K were then used to vary the porosity (6–50%) and surface area (2–800 m²/g), and to produce pore size distributions that include both micro and transitional pores. As the temperature rises, the size and the volume of the micropores increase at the expense of the skeletal volume and then their size distribution becomes more narrow. Partial oxidation at elevated temperatures opens and enlarges existing porosity and catalyzes multiphase graphitization of many of the mixed-polymer chars.

Additional details