Influence of alkylpyridinium cation length on the sorption properties of template-containing mesoporous molecular sieves

Mesoporous MSM-41 molecular materials containing alkylpyridinium templates are shown to have the properties of microporous sorbents. Characteristic energy of the sorption in micropores of these materials decreases as the surfactant hydrocarbon radical lengthens, irrespective of a sorbate type. The sorption volume of the pores of template-containing MSM-41 sieves accessible to water and methanol vapors decreases with the lengthening of the hydrophobic radical of a template. This dependence has an extremal pattern for the sorption of propanol-2 and hexane vapors. A conclusion is drawn that, under the chosen synthesis conditions of the mesophase materials, the packing density of surfactant molecules in encapsulated micelles increases with the lengthening of the alkyl radical. It is assumed that the differences in the packing densities of surfactant molecules substantially explain the characteristic sorption properties and the perfection of the hexagonal structure of prepared MSM-41 mesophase materials.