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The thermally stable zirconium-based MOF, UiO-66, was employed for the preparation of bonded porous-layer open-tubular (PLOT) GC columns. The synthesis included the in situ growth of the UiO-66 film on the inner wall of the capillary through a one-step solvothermal procedure. SEM–EDX analysis revealed the formation of a thin, continuous, uniform, and compact layer of UiO-66 polycrystals on the functionalized inner wall of the column. The average polarity (ΔIav = 700) and the McReynolds constants reflected the polar nature of the UiO-66 stationary phase. Several mixtures of small organic compounds and real samples were used to evaluate the separation performance of the fabricated columns. Linear alkanes from n-pentane to n-decane were baseline separated within 1.35 min. Also, a series of six n-alkylbenzenes (C3–C8) were separated within 3 min with a minimum resolution of 3.09, whereas monohalobenzene mixtures were separated at 220 °C within 14s. UiO-66 PLOT columns are ideally suited for the isothermal separation of chlorobenzene structural isomers at 210 °C within 45 s with Rs ≥ 1.37. The prepared column featured outstanding thermal stability (up to 450 °C) without any observed bleeding or significant impact on its performance. This feature enabled the analysis of various petroleum-based samples. [ABSTRACT FROM AUTHOR]

In this work, an innovative ionic liquid functionalized star-shaped polymer is synthesized by coupling star-polycaprolactone with benzimidazolium (star-PCL-Bim), and statically coated into a capillary column for gas chromatographic (GC) separations. The fabricated star-PCL-Bim capillary column with moderate-polar nature reveals a high column efficiency of 3598 plates/m for n-dodecane at 120 °C, and advantageous distinguishing ability (R > 1.5) for 9 aromatic isomer mixtures and 12 cis-/trans-isomers. Its excellent resolving capacity can be credited to the architecture of star-PCL-Bim, the PCL arms, and π-electron-rich benzimidazolium cations, and it results in a quite different retention behavior of star-PCL-Bim from that of star-PCL and commercial HP-35 columns, with "dual-nature" selectivity in separating a mixture including 29 compounds. These favorable chromatographic characteristics demonstrate the great application potential of this material in GC, and provide a prospective strategy to obtain high-performance stationary phases. [ABSTRACT FROM AUTHOR]

The Schiff bases reaction is applied to form various functioned carbon structures using renewable carbon from waste sources, Chitosan, 4-Amino-3-hydroxy-napthalene-1-sulphnic acid, and dimethyl amino benzaldehyde as starting materials. The formed functioned carbons were characterized by TEM, FTIR, XRD, and surface area analysis to assess their morphology, structure, porosity, and surface functional groups. In addition, the chromatographic-based thermodynamic analysis is applied to evaluate the surface energy and thermodynamic parameters during the separation of hydrocarbon species. Results indicated the formation of various carbon structures in convex-like shapes with diameters between 600 nm and 1500 nm, including side-building edges of diameter between 100 nm and 316 nm. The formed functioned carbon surfaces are rich with O-H, N=C, C=C, C=O, and C=S groups, as indicated by the FTIR. The function carbons are named carbon coated with Chitosan-derived covalent organic layer (C@Chitosan-COL) as well as Schiff's base-derived sulfonated carbon (Schiff's-C-S) in relation to the applied starting materials. The chromatographic-based thermodynamic analysis showed that the entropy changes of adsorption (ΔSA) increased with increasing chain length demonstrating less random movement and higher adsorption in both materials. The fabricated C@Chitosan-COL and Schiff's-C-S showed an efficient separation of hydrocarbon mixture including n-Nonane, n-Decane, n-Undecane, and n-Dodecane. [ABSTRACT FROM AUTHOR]