Core-shell MOFs-based composites of defect-functionalized for mixed-mode chromatographic separation.

Area of Science:

• Materials Science
• Analytical Chemistry
• Nanotechnology

Background:

• Traditional metal-organic frameworks (MOFs) possess micropores limiting diffusion and transport control.
• Hierarchical porous materials offer advantages in controlling diffusion and transport processes.

Purpose of the Study:

• To develop a novel hierarchical porous material by incorporating L-Cysteine into MOFs via defect-loading.
• To create advanced mixed-mode stationary phases for enhanced chromatographic separations.
• To investigate the role of MOF defects and L-Cysteine functionality in separation mechanisms.

Main Methods:

• Preparation of hierarchical porous MOFs with functional defects through L-Cysteine incorporation.
• Modification of silica microspheres with these MOF composites to form core-shell structures.
• Application of the developed core-shell composites as mixed-mode stationary phases in chromatography.

Main Results:

• The novel MOF-based stationary phase demonstrated superior efficiency and selectivity compared to traditional MOFs.
• Effective separation of hydrophobic compounds, hydrophilic analytes, carbohydrates, and sulfonamides was achieved.
• Excellent chromatographic reproducibility and stability were observed, with preparation repeatability below 1.81% RSD.

Conclusions:

• Defect engineering in MOFs, combined with L-Cysteine functionalization, creates highly effective stationary phases.
• The developed material provides deep insights into separation mechanisms for MOF-based composites.
• This strategy stimulates the broad application of defective MOFs in separation science and analytical chemistry.