Homomesoporous Metal-Organic Framework for High-Performance Electrochromatographic Separation

Area of Science:

• Separation science
• Materials science
• Analytical chemistry

Background:

• Metal-organic frameworks (MOFs) show promise for separation science.
• Existing MOF stationary phases with microporous structures have limited separation performance.
• Homomesoporous MOFs offer improved mass transfer and thermodynamic interactions.

Purpose of the Study:

• To explore homomesoporous MOFs as novel stationary phases for high-performance capillary electrochromatographic separations.
• To demonstrate the effectiveness of a specific homomesoporous MOF (mesoMOF-1) as a stationary phase.
• To investigate the separation mechanisms and performance of homomesoporous MOF stationary phases.

Main Methods:

• Facile growth of noninterpenetrated mesoMOF-1 on capillary inner surfaces.
• Application of mesoMOF-1 as a homomesoporous MOF coating-based stationary phase.
• High-performance capillary electrochromatographic separation of seven analytes with varying molecular dimensions.
• Comparison with a microporous HKUST-1 coated column.
• Analysis of adsorption kinetics and chromatographic retention behaviors.

Main Results:

• mesoMOF-1 coated column achieved baseline separation of analytes with high theoretical plate numbers and excellent repeatability.
• Significantly improved separation selectivity and column efficiency compared to microporous HKUST-1.
• Maximum column efficiencies reached 1.4 × 10^5 plates/m for substituted benzenes and halobenzenes.
• Higher mass loadability observed for the mesoMOF-1 coated column.
• Systematic exploration and disclosure of interaction and retention mechanisms.

Conclusions:

• Homomesoporous MOF-based stationary phases effectively balance kinetic diffusion and thermodynamic interactions.
• These novel phases offer great potential for high-performance chromatographic separations.
• mesoMOF-1 represents a promising material for advanced electrochromatographic applications.