T. Steriotis et al., ON THE STRUCTURE OF AN ASYMMETRIC CARBON MEMBRANE WITH A NOVOLAC RESIN PRECURSOR, Journal of applied polymer science, 64(12), 1997, pp. 2323-2345
An asymmetric tubular carbon membrane, appropriate for gas separation
applications, was made through carbonization at 800 degrees C of a pre
cursor structure containing two phenol-formaldehyde resins, a partiall
y cured novolac resin in 30-60 mu m grains (bulk material), and a reso
le resin (membrane, skin material). A replica of the skin material was
deposited separately on a stainless steel substrate. The samples were
analyzed by nitrogen adsorption, small-angle neutron scattering, and
scanning electron microscopy (SEM). The basic structural entities of b
oth skin and the bulk part were low-aspect-ratio carbon domains with a
characteristic dimension in the 4.0-4.5 nm range. Further, the materi
als were characterized by microporosity in the 0.30-0.50 range with is
otropic pores having a 1.3 nm diameter. The results are discussed with
the help of a systematic survey of possible carbon structures with an
intermediate level of microporosity. (C) 1997 John Wiley & Sons, Inc.