Investigation of n-alkane adsorption on HKUST-1 and determination of intrinsic interfacial energy contributions

Abstract

The performance of metal-organic frameworks in gas chromatographic separation investigations has been widely study in recent years. However, to use chromatographic methods to determine materials properties of metal-organic frameworks instead of using them just for analyte separations is a field still largely unexplored. The presented study has been conducted to quantify the systematic changes in the interaction of a series of related unbranched aliphatic analytes (C2-C10) with HKUST-1 as the stationary phase not only to obtain information about the MOF analyte interaction strength but also to gain materials parameters characterizing the MOF system, like its response to non-specific interactions. Thermodynamic as well as by kinetic parameters governing the adsorption process were determined using various chromatographic evaluation techniques. The method of inverse chromatography was used to derive the generic susceptibility of HKUST-1 to aliphatic methylene groups and to determine interfacial energy contributions of the intrinsic surface of the porous material.