Controlled Iodine Phase Transfer of Covalent Organic Framework Membranes for Instant but Sustained Disinfection

Freestanding membranes of CuCl2-implanted TpPa covalent organic frameworks (COFs) were mechanochemically produced. The resulting membrane had a high I2 adsorption capacity (566.78 g·mol–1) in cyclohexane, which corresponds to 2.2I2 per unit cell with 1.3I2 immobilized on 3Cl– ions (60%) and 0.9 on 3N atoms (40%). Upon being placed in aqueous media, the membrane released 61.1% of its loaded I2 mainly by its Cl– ions within 10 min and the remaining 38.9% mainly from its N atoms within about 5 h. Thanks to that, the COF membranes loaded with 1.5 mg of I2 could be repetitively utilized to kill about 108 CFU/mL E. coli in 0.5–3 min at least five times, after which the membranes could retain their bactericidal activity for 4 h against 108 CFU/mL E. coli. This highlights the promising application of I2-loaded TpPa-CuCl2 COF membranes for instant and sustained disinfection.