Facile synthesis and immobilization of functionalized covalent organic framework-1 for electrochromatographic separation

Inspired by the outstanding functions of 3-aminopropyltriethoxysilane (APTES), which can be used for functionalization of both covalent organic frameworks (COFs) and substrate surfaces, herein, a proof-of concept demonstration was carried out by one-step synthesis and immobilization of COF-1 in capillary. COF-1 was grown on the inner wall of capillary using APTES, which played a triple role of catalyst, stabilizer, and connecting arm during the process. The immobilization of COF-1 on silicon surface was confirmed by scanning electron microscopy. Moreover, COF-1 modified capillary (COF-1@capillary) column exhibited excellent performance in the electrochromatographic separation of amino acids. High resolution and separation efficiency (225,378 plates/m for 4-methylbiphenyl) were successfully achieved. Separation of methylbenzene, styrene, ethylbenzene, chlorobenzene, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene, 4methylbiphenyl, naphthalene, and 4-vinylbipheny in the electro-driven mode confirmed the successful growth of COF-1 on the inner wall of capillary. The developed facile method for the immobilization of COF-1 may pave the way for further application prospects of boron-based COFs. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

This study successfully demonstrated the one-step synthesis and immobilization of COF-1 in a capillary using APTES, showing excellent performance in the electrochromatographic separation of amino acids. The modified capillary column exhibited high resolution and separation efficiency, paving the way for further application prospects of boron-based COFs.