Inverse gas chromatography for determining the dispersive surface energy of porous silica

Inverse gas chromatography (IGC) is a modern technique for the characterization of porous materials, which provides thermodynamic parameters of the solids. Porous glass beads, silica gels and ordered mesoporous materials were used as model systems to study correlations between the dispersive part of the surface energy and the surface chemistry of porous materials. The surface chemistry of silica was controlled via thermal treatment and reaction with 1,1,1,3,3,3-hexamethyldisilazane (HMDS) or 3-amino-propyltriethoxysilane (3-APTS). The dependency of the surface energy on the various modifications was investigated in this study. Furthermore, the impact of microstructure on the dispersive surface energy was determined by a comparative study of the ordered mesoporous materials MCM-41, SBA-15 and SBA-16.