Hyperbranched molecularly imprinted covalent organic framework (COF) microcapsules for highly specific adsorption of flavonoids

Microcapsule materials with selective mass transfer and mechanical stability are considered one of the potential adsorbents in the field of natural active molecules separation. Herein, a new kind of porous boronic acid affinity imprinted covalent organic framework (COFs) microcapsules (DR-MC@PDA@MIPs) via W/O type Pickering emulsion interface polymerization were fabricated for adsorption of naringin (NRG). During the emulsion interface assembly process, the dopamine-modified COF particles (BTCA-COFs@PDA) were stabilized at the water/oil phase interface, followed by the catalytic growth of COFs shell layers via multi-phase emulsion interface. For improve the specific adsorption amounts, the dendritic initiator (Y-Shape-(Br) 2 ) were modified onto the surface of COFs based MC. Ultimately, the DR-MC@PDA@MIPs were fabricated through atom transfer radical polymerization (ATRP). The prepared DR-MC@PDA@MIPs exhibited high enrichment amounts and good NRG selectivity under neutral conditions, with a rapid adsorption equilibrium rate (120 min) and an adsorption capacity for NRG (72.32 μmol/g). Furthermore, DR-MC@PDA@MIPs showed a higher imprinting factor (3.126) compared to non-imprinted adsorbents (DR-MC@PDA@NIPs). After seven separation cycles, the obtained DR-MC@PDA@MIPs exhibited good reusability, with an adsorption capacity of 92.38% of the first adsorption-elution cycle. The DR-MC@PDA@MIPs selectively purified crude NRG products to 94.51%. Therefore, this work provides a new boronic acid affinity COFs MC imprinted MC in the specific separation of targeted flavonoid molecules, overcoming some limitations of traditional microcapsule adsorbents and advancing further research and applications in the selective separation field.