Selective Properties of Carbon Adsorbent Modified by Mixed Adsorption Layer of the "Liquid Crystals – β-Cyclodextrin" Modifier Under Gas Adsorption Chromatography Conditions

Supramolecular Planar Liquid Crystal Systems on Carbon Surface as Universal Isomer-Selective Adsorbents

“…The initial CpY adsorbentcarrier was successively modified with a monolayer of supramolecular LC from a chloroform solution, and then with β-CD from an aqueous-ammonia solution. It has been established that modification of CpY with polar HEOCAB and β-CD leads to formation of mixed adsorption layer due to the solvation of components, which prevents the formation of «host − guest» inclusion complexes during adsorption from gas phase [19]. For two other adsorbents (CpY/HPOFAB/β-CD and CpY/8OCB/β-CD [20]), the layer-by-layer assembly was used to obtain bilayer structures with alternating LC and macrocycle monolayers on CpY surfaces with an approximate calculated bilayer thickness of 13−20 Å, depending on the orientation of β-CD molecules relatively to the planar premonolayer of the LC orientant.…”

Isomer-Selective Properties of Carbon Adsorbent Modified by "4-n-octyloxy-4'-cyanobiphenyl – β-Cyclodextrin" under Gas-Adsorption Chromatography Conditions

“…Earlier, in the [12] work we studied selective properties of the carbon graphite-like adsorbent Carbopack Y (CpY) modified with a mixed adsorption layer of the associate (supramolecular) mesogen 4-(2hydroxyethyloxy)-4'-cyanoazoxybenzene (HEOCAB) and unsubstituted β-cyclodextrin (β-CD). It has been discovered that this adsorbent selectively adsorbs structural isomers and enantiomers of polar compounds from the gas phase, while the selectivity to the low polarity enantiomers is practically absent.…”