Adsorption of Organic Substances on Carbon Blacks, Modified by Monolayers of Polar Anisometric Molecules

Abstract
Thermodynamic characteristics of adsorption of organic compounds on carbon adsorbent Carbopack Y (CpY) before and after drawing a monomolecular layer of tetrakis(dodecanoyloxy)hydroquinone (TDHQ) on its surface are measured by gas chromatographic method. Adsorption properties of CpY / TDHQ and graphitized thermal carbon black modified by nematic crown-ether are compared. It is shown that drawing of monolayers of polar modifiers on a carbon substrate leads to occurrence of specific intermolecular interactions «polar adsorbat – adsorbent». Isomeric xylens are selectively adsorbed on the considered modified adsorbents. The sequence, in which Henry's constants increase (meta- → para- → ortho-), testifies that molecules of the modifiers form orientation ordered monolayers on carbon substrates.

Keywords: gas-solid chromatography, modified carbon adsorbents, "adsorbat – adsorbent" interactions