The Monte-Carlo molecular modeling of non-rigid organic molecules for prediction their retention properties

Abstract

The Monte-Carlo molecular modeling of adsorption of organic molecules on Graphitized Thermal
Carbon Black (GTCB) is provided in this work. Only that conditions are considered, where Henry’s law is
applicable. Modified GAFF (General Amber Force Field) force field and simplified model of molecule with
rigid bond lengths and angles are used. Crowell’s approach for efficient calculation of potential energy of
interactions between organic molecule and graphitic layer is applied. Good agreement with experiment is
demonstrated for many organic molecules: alkanes (CH4-C12H26), chloroalkanes, alkylbenzenes, ethers. Satisfactory
correlation between experimental and calculated data is achieved. New approach is compared with
molecular statistical method, which is used to calculate characteristics of adsorption on GTCB. Advantage of
this approach is shown. Influence of adsorption on graphitic surface at conformation of molecule is discussed.
Possible effect of systematic error in experimental data is shown. All calculations are perfomed with
self-written software.