title: Analysis of Adsorbate-Adsorbate and Adsorbate-Adsorbent Interactions to Decode Isosteric Heats of Gas Adsorption.
abstract: A qualitative interpretation is proposed to interpret isosteric heats of adsorption by considering contributions from three general classes of interaction energy: fluid-fluid heat, fluid-solid heat, and fluid-high-energy site (HES) heat. Multiple temperature adsorption isotherms are defined for nitrogen, T=(75, 77, 79) K, argon at T=(85, 87, 89) K, and for water and methanol at T=(278, 288, 298) K on a well-characterized polymer-based, activated carbon. Nitrogen and argon are subjected to isosteric heat analyses; their zero filling isosteric heats of adsorption are consistent with slit-pore, adsorption energy enhancement modelling. Water adsorbs entirely via specific interactions, offering decreasing isosteric heat at low pore filling followed by a constant heat slightly in excess of water condensation enthalpy, demonstrating the effects of micropores. Methanol offers both specific adsorption via the alcohol group and non-specific interactions via its methyl group; the isosteric heat increases at low pore filling, indicating the predominance of non-specific interactions.
authors.affiliation: Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA, 5095, Australia), Tel: +61 (0)8 8302 2188.
authors.forename: S Hadi
authors.initials: SH
authors.lastname: Madani
authors.affiliation: School of Chemical Engineering, University of Adelaide, Adelaide, SA, 5005, Australia.
authors.forename: Saeid
authors.initials: S
authors.lastname: Sedghi
authors.affiliation: School of Chemical Engineering, University of Adelaide, Adelaide, SA, 5005, Australia.|School of Science, Loughborough University, LE11 3TU, Leicestershire, UK.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Biggs
authors.affiliation: Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA, 5095, Australia), Tel: +61 (0)8 8302 2188. Phillip.Pendleton@unisa.edu.au.|Sansom Institute, University of South Australia, Adelaide, SA, 5001, Australia. Phillip.Pendleton@unisa.edu.au.
authors.forename: Phillip
authors.identifier: http://orcid.org/0000-0003-1031-8170
authors.initials: P
authors.lastname: Pendleton
keywords: condensation heat; gas adsorption; isosteric heat of adsorption; non-specific interactions; specific interactions