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.

This study delves into the thermodynamics of liquid-phase adsorption on hypercrosslinked polystyrene networks (HPSNs), widely recognized for their distinct structure and properties. Despite the considerable progress in HPSN synthesis and characterization, gaps persist regarding the chromatographic retention mechanism, thermodynamics of adsorption, and their impact on the adsorption selectivity, especially in the case of networks with ultra-high crosslinking densities (up to 500%). Utilizing high-performance liquid chromatography (HPLC), we have explored, for the first time, the thermodynamic intricacies of liquid-phase adsorption onto HPSNs crosslinked in the entire range of the crosslinking degree from 100 to 500%.

Understanding the Working Mechanism of the Novel HKUST-1@BPS Composite Materials as Stationary Phases for Liquid Chromatography.

Composite materials have been used based on coordination polymers or microporous metal-organic frameworks (MOFs) combined with mesoporous matrices for adsorption-related techniques, which enable outflanking some adverse phenomena manifested during pristine components operation and enhance the performance and selectivity of the resulting materials. In this work, for the first time, the novel HKUST-1@BPS composites synthesized by the microwave-assisted (MW) technique starting from microporous HKUST-1 (Cu(btc)) MOF and biporous silica matrix (BPS) with bimodal mesopore size distribution were comparatively studied as materials for liquid-phase adsorption techniques utilizing the high-performance liquid chromatography (HPLC) method and benzene as a model adsorbate. It was established that the studied HKUST-1@BPS composites can function as stationary phases for HPLC, unlike the pristine HKUST-1 and bare BPS materials, due to the synergetic effect of both components based on the preliminary enhanced adsorbate mass transfer throughout the silica mesopores and, subsequently, its penetrating into HKUST-1 micropores.

Impact of the Preparation Procedure on the Performance of the Microporous HKUST-1 Metal-Organic Framework in the Liquid-Phase Separation of Aromatic Compounds.

To date, metal-organic frameworks (MOFs) have been recognized as promising solid phases in high-performance liquid chromatography (HPLC). This research aimed to elucidate the role of the physico-chemical characteristics of the microporous HKUST-1 metal-organic framework in its operation as a selective adsorbent in HPLC. For this, the HKUST-1 samples were prepared by microwave-assisted synthesis and a solvothermal procedure.