A New Topological Index for Molecular Probes Used in Inverse Gas Chromatography for the Surface Nanorugosity Evaluation

✍ Scribed by Eric Brendlé; Eugène Papirer

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 174 KB
• Volume: 194
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.1997.5104

✦ Synopsis

Several methods are recommended for the determination Inverse gas chromatography is currently used for the determinaof adsorption isotherms: static methods such as volumetry tion of the surface properties of divided solids by probing the or gravimetry, but also dynamic methods such as inverse gas surface with alkanes or polar molecules of known properties. This chromatography (IGC). We privileged this latter because it paper suggests the use of a new topological index for the descripreadily gives access to the desorption isotherms in a large tion of the probe's (alkanes) geometry and hence of their accessirange of temperatures and for a variety of adsorbates. Furbility to the solid's surface. The proposed index (x T ) derives from thermore, it permits the precise evaluation of the initial part the well known Wiener index. The application of x T for the deterof the isotherm: the one corresponding to the adsorption on mination of the dispersive component of the surface energy of the most energetic adsorption sites, i.e., those we are interpyrogenic silica, but also for the evaluation of the geometric heterogeneity of lamellar silica, is described. Further, goethite and zirco-ested in for the description of surface heterogeneity. nia samples were submitted to similar analysis.