Small angle X-ray scattering studies on carbons derived from polyfurfuryl alcohol and polyfurfuryl alcohol-ferrocene copolymers

Abstract

Small angle X-ray scattering techniques have been used to characterize the porous nature of glassy carbons derived from polyfurfuryl alcohol (PFA) and from PFA-ferrocene derivative copolymers. Samples were prepared under controlled heating conditions within the temperature range 970–2500°C. For carbons produced only from PFA it is shown that each contains micropores of a narrow size distribution. As heat treatment temperature increases there is a progressive development of both pore structure and of order within the carbon matrix. A comparison is made of specific surface area results for PF'A carbons as measured by small angle X-ray procedures and by CO 2 at −78°C. The small angle X-ray results for the materials produced from the iron-containing precursors indicate the presence of two distinct regions of heterogeneity in the carbon matrix. One is microporous and the other is of larger pores of a much wider size distribution. It is also suggested that these larger pores account for these carbons having lower tensile strength and higher electrical resistivity than a corresponding PFA carbon.