Systematic regulation of pore microenvironments: Thermodynamics and mass transfer kinetics of functionalized UiO-66 chromatographic stationary phases

A uniformly functionalized UiO-66 capillary column with a continuous flow process was prepared. • The hydrophobic pore channel microenvironment (−2CH 3 ) significantly reduces the mass transfer resistance of non-polar molecules. • The polar group (−2SH) triggers specific adsorption of noble gases within the confined pores. • The GCMC simulation quantitatively revealed the thermodynamic essence of the functional group control over adsorption heat. • A structure-activity relationship was established, mapping from functional group design to chromatographic performance. To address the challenges posed by the ill-defined regulatory mechanisms of pore microenvironments in metal-organic framework (MOF) chromatographic stationary phases, this study employs continuous flow synthesis to fabricate a series of functionalized UiO-66 wall-coated open-tubular column with precisely controlled thicknesses. This approach aims to decouple physical morphological interference and systematically elucidate intrinsic separation principles. In the thermodynamic dimension, the retention of aromatic compounds is synergistically governed by framework shape selectivity and π–π interactions. Conversely, for permanent gases where size-sieving is restricted, thiol functionalization achieves successful baseline separation through physical confinement and the induction of specific dipole-quadrupole interactions. Grand Canonical Monte Carlo (GCMC) simulations quantitatively confirm a significant elevation in the isosteric heat of adsorption at the molecular scale, which corroborates the macroscopic chromatographic performance. Long-term stability tests (RSD < 0.28 %) further validate the physicochemical robustness endowed by the synergy between Zr-O coordination bonds and covalent modification groups. This work provides a definitive methodological basis for the theoretical customization and engineering-scale fabrication of high-performance MOF stationary phases.