Chromatographic separation performance of silica microspheres surface-modified with triazine-containing imine-linked covalent organic frameworks

In this work, 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (TAPT) and 1,3,5-tris(4-formylphenyl)benzene (TFPB) were used as monomers to construct a triazine-containing imine-linked covalent organic framework (COF), which was then bonded onto the surface of aldehydized silica (SiO 2 –CHO), and finally a COF@silica composite material (TAPT-TFPB COF@SiO 2 ) was successfully prepared. The chromatographic separation performance of SiO 2 –CHO, TAPT-TFPB COF@SiO 2 and TAPT-TFPB COF@SiO 2 /SiO 2 –CHO (80/20, mass ratio) was evaluated and compared. It was found that separation efficiency was obviously enhanced by adding an appropriate amount of SiO 2 –CHO into TAPT-TFPB COF@SiO 2 . The obtained TAPT-TFPB COF@SiO 2 /SiO 2 –CHO showed more favorable separation ability than SiO 2 –CHO and TAPT-TFPB COF@SiO 2 . Various aromatic compounds including alkylbenzenes , polycyclic aromatic hydrocarbons , environmental endocrine disruptors , foodborne stimulants and phenyl ketones were effectively separated on the TAPT-TFPB COF@SiO 2 /SiO 2 –CHO column in reversed phase chromatography mode. The silica microspheres surface-modified with triazine-containing imine-linked COFs proved to be a new type of promising chromatographic packing materials.