posted on 2022-11-18, 04:33authored byYuanqi Gui, Jing Zeng, Lujun Wang, Wenwen Long, Mingyue You, Xueping Tao, Yike Huang, Zhining Xia, Li Rao, Qifeng Fu
Metal–organic
frameworks (MOFs) have exhibited
tremendous
potential in the area of separation science. However, most of the
developed MOF-based stationary phases contained only microporous structures
and suffer from limited separation performance. Herein, homomesoporous
MOFs with excellent mass transfer capability and strong thermodynamic
interactions are first explored as the novel stationary phase for
high-performance capillary electrochromatographic separations. As
a proof of concept, noninterpenetrated mesoMOF-1 with uniform mesopore
sizes (22.5 × 26.1 Å) and good stability was facilely grown
on the inner surface of capillaries and applied as a homomesoporous
MOF coating-based stationary phase for high-efficiency electrochromatographic
separation. Seven types of analytes with different molecular dimensions
were all baseline separated on a mesoMOF-1 coated column with high
theoretical plate numbers and excellent repeatability, exhibiting
significantly improved separation selectivity and column efficiency
in comparison to a microporous HKUST-1 coated column. The maximum
column efficiencies of the mesoMOF-1 coated column for substituted
benzenes and halobenzenes reached up to 1.4 × 105 plates/m,
and its mass loadability was also much higher than that of the HKUST-1
coated column. In addition, based on the analysis of adsorption kinetics
and chromatographic retention behaviors, the interaction and retention
mechanisms of different molecular-weight analytes on mesoMOF-1 coated
stationary phases were systematically explored and disclosed in detail.
These results indicate that the homomesoporous MOF-based stationary
phase can effectively balance the kinetic diffusion (mass transfer
capability) and thermodynamic interactions (the strength of adsorption
interaction), having great potential for high-performance chromatographic
separation.