Influence of the Functional Groups of Modifying Chelates on the Adsorption of Aromatic Hydrocarbons by the Silica Surface

Adsorbents based on Silipore 200 silica noncovalently modified with complex compounds of nickel(II) with acetylacetone, benzoylacetone, and ethyl acetoacetate were obtained. The interaction of the vapors of aromatic compounds with the silica surface was studied by gas chromatography: the Henry constants were calculated, the thermodynamic characteristics of adsorption of the class of compounds under study were determined based on chromatographic data, and the contributions of modifying additives to the retention of adsorbates were calculated. The effects of the ligand functional groups in the chelate complex on the differential molar heat of adsorption and the change in the adsorption entropy were studied. The possibility of using the sorbents for gas chromatographic separation of complex mixtures of organic compounds was shown.