Fast and facile sonochemical fabrication of covalent organic frameworks in water for the adsorption of flavonoids: Adsorption behaviors and mechanisms

Solvothermal synthesis of covalent organic frameworks (COFs) typically requires high temperatures exceeding 120 degrees C, large amounts of toxic organic reagents, and reaction durations spanning 3-7 days. In contrast, a new COF (TFPPy-AD) was rapidly synthesized by the sonochemical method at room temperature within just 60 min, eliminating the need for toxic reagents. The characterization of the material showed that TFPPy-AD was successfully synthesized with notable features such as a large pore size, high crystallinity, and good thermal stability. Subsequent adsorption experiments highlighted the material's exceptional adsorption capacity and selectivity for flavonoids. The adsorption mechanism of flavonoids onto TFPPy-AD likely involves a combination of sieve interactions, hydrogen bonding interactions, hydrophobic interactions, and it-it interactions. This sonochemically synthesized COF exhibits promising attributes including high adsorption capacity, selectivity, and rapid adsorption rate for flavonoids, suggesting potential applications in the separation and purification of flavonoids in natural medicines.