posted on 2018-07-11, 14:32authored byS. Hadi Madani, Francisco Rodríguez-Reinoso, Mark J. Biggs, Phillip Pendleton
High-resolution,
multiple temperature adsorption isotherms of ten
adsorptives classified into highly polar (1.7 ± 0.1 D) and nonpolar
(0 D) probes with increasing kinetic diameters were measured on a
well-characterized poly(furfuryl alcohol)-based microporous carbon.
The Clausius–Clapeyron equation was applied to each, resulting
in isosteric heats of adsorption. Fluid–fluid interactions,
nonspecific fluid–solid interactions, and specific fluid–high
energy site interactions were identified and discussed as variables
contributing to the total isosteric heat of adsorption. Each isosteric
heat was compared against its position relative to adsorption heat
by a flat surface, twice this heat, and adsorptive latent heat of
condensation. The shape of each curve was analyzed via the contribution
of each interaction to the total across the fractional filing range,
leading to identification of fillings as Zero Coverage, Low Coverage,
and High Coverage. This systematic investigation provided a detailed
analysis of the influences of adsorptive size, its conformation, and
polarity effects on micropore filling, and tabulation of the analyses
gave a clear and comprehensive insight into the adsorption mechanisms.