Porous graphite as stationary phase for the chromatographic separation of polymer additives - determination of adsorption capability by Raman spectroscopy and physisorption

Thermodynamic Characteristics and Selectivity of the Liquid-Phase Adsorption of Aromatic Compounds on Hypercrosslinked Polystyrene Networks with Ultimate-High Crosslinking Densities by Data of Liquid Chromatography

“…According to the obtained data, liquid-phase adsorption on HPSNs is a Benzothiophene Table 3. Structural formulae of the studied aromatic compounds (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18) 4 presents the Henry adsorption constants K1,c and standard molar Gibbs energies ΔaG* of the adsorption of the studied aromatic compounds (1-18) from a MeCN-H2O (60:40 v/v) solution on the HPSs with different crosslinking degrees X at a temperature of 323 K. Herein, the thermodynamic characteristics of liquid-phase adsorption of the studied aromatic compounds on the HPS samples with X = 100, 200% are reported for the first time and compared with values previously measured by us for polymers with X = 300-500% [31]. According to the obtained data, liquid-phase adsorption on HPSNs is a 4 presents the Henry adsorption constants K1,c and standard molar Gibbs energies ΔaG* of the adsorption of the studied aromatic compounds (1-18) from a MeCN-H2O (60:40 v/v) solution on the HPSs with different crosslinking degrees X at a temperature of 323 K. Herein, the thermodynamic characteristics of liquid-phase adsorption of the studied aromatic compounds on the HPS samples with X = 100, 200% are reported for the first time and compared with values previously measured by us for polymers with X = 300-500% [31].…”

“…The proposed hypothesis is an attempt to shed light on the fact that the HPSNs with the odd crosslinking degrees exhibit elevated values of thermodynamic characteristics of adsorption compared with polymers crosslinked up to even crosslinking degrees. 6 shows the Henry adsorption constants K 1,c and standard molar Gibbs energies ∆ a G* of the adsorption of the studied different aromatic compounds (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18) from solutions of varying MeCN-H 2 O compositions (v/v) onto the HPS sample with a crosslinking degree of X = 300% at a temperature of 323 K. The Henry constants of adsorption become notably high when tricyclic aromatic compounds are adsorbed from the MeCN-H 2 O mixture with the highest water content. This is because, in addition to dispersive van der Waals forces and ππ-interaction, hydrophobic expulsion manifests during adsorption from this polar medium onto the nonpolar HPS interface [42].…”

“…In addition to conventionally employed chemically modified silica gels [6] and infrequently utilized porous graphitic carbon [7], contemporary research focuses on state-ofthe-art nanoporous three-dimensional adsorbing materials, proposed as HPLC stationary phases, such as metal-organic coordination polymers [8] and hypercrosslinked polymers [9]. Hypercrosslinked polystyrene networks (HPSNs) are considered to be prominent among the latter.…”