Highly efficient removal of Aflatoxin B1 employing a flower-like covalent organic framework-based fiber membrane

Mycotoxin pollutants removal using adsorbents has been studied extensively in recent years, although the development of low-cost, recyclable, and highly efficient adsorbents remains a challenge to date. Covalent Organic Frameworks (COFs) represent a novel kind of porous crystalline material, which have been applied widely. In this work, a flower-like COF fiber membrane (PAN@COF FM) for adsorbing Aflatoxin B1 was fabricated using a simple approach. The COF was grown on the surface of polyacrylonitrile (PAN) skeleton using the in situ growth method. Then, the AFB1 adsorption performance of the prepared membrane and the underlying adsorption mechanism were studied. The results revealed that the activated PAN@COF FM reached adsorption equilibrium within 30 min. The used membranes were regenerated by washing with an alkaline solution and then tested for adsorption efficiency again. The PAN@COF FM could adsorb above 98% Aflatoxin B1 after 10 cycles, indicating its good reusability. The well adsorption performance of the membrane was attributed to the rr-rr stacking, hydrogen bonding, and hydrophobic interactions between PAN@COF FM and Aflatoxin B1. In summary, the as-prepared PAN@COF FM possesses the advantage of high reusability and good adsorption performance, and has the promising application in pollutant removal.