Preparation of a Hydrophobic Fluorine-Containing Covalent Organic Framework and Its Interfacial Applications

Hydrophobic porous materials are of significant interest due to their potential for various large-scale industrial applications. In this study, we introduce the synthesis of a hydrophobic fluorine-containing covalent organic framework (F-COF), TAPB-TFA, using a low-temperature method, along with its applications in liquid marbles and oil/water separation. By a scandium(III) trifluoromethanesulfonate-catalyzed Schiff-base reaction, uniform spherical TAPB-TFA particles at the nanoscale are successfully synthesized. Results show that TAPB-TFA exhibits high crystallinity, excellent thermal and chemical stability, as well as superoleophilic/hydrophobic properties. The hydrophobic TAPB-TFA particles can be utilized to create various liquid marbles that exhibit excellent shape reconfigurability. Experiments confirm the outstanding performance of TAPB-TFA in separating oil/water mixtures and water-in-oil emulsions, achieving a separation efficiency of over 98.5%. The analysis concludes that the exceptional separation performance of TAPB-TFA is attributed to the synergistic effects of surface wetting-induced aggregation and size-sieving. TAPB-TFA demonstrates significant potential for applications in the environmental and energy sectors.