title: Pore anisotropy and microporosity in nanostructured mesoporous solids.
abstract: In this study, we carried out an investigation related to the determination of the anisotropy (b) of pores as well as the extent of microporosity (mic%) in various groups of nanostructured mesoporous materials. The mesoporous materials examined were fifteen samples belonging to the following groups of solids: MCM-48s, SBA-15s, SBA-16s, and mesoporous TiO(2) anatases. The porosities of those materials were modified either during preparation or afterward by the addition of Cu(II) species and/or 3(5)-(2-pyridinyl) pyrazole (PyPzH) into the pores. The modification of porosity in each group took place to make possible the internal comparison of the b and mic% values within each group. The estimation of both the b and mic% parameters took place from the corresponding nitrogen adsorption-desorption isotherms. The new proposed method is able to detect a percentage of microporosity as low as a few percent, which is impossible by any of the methods used currently, without the use of any reference sample or standard isotherms. A meaningful inverse relationship is apparent between the b and mic% values, indicating that large values of b correspond to small values of mic%.
authors.affiliation: School of Chemistry, University of Reading, Whiteknights, Reading RG6 6BD, Great Britain.
authors.forename: John
authors.initials: J
authors.lastname: Knowles
authors.forename: Gerasimos
authors.initials: G
authors.lastname: Armatas
authors.forename: Michael
authors.initials: M
authors.lastname: Hudson
authors.forename: Philippos
authors.initials: P
authors.lastname: Pomonis