Hollow imprinted polymer nanorods with a tunable shell using halloysite nanotubes as a sacrificial template for selective recognition and separation of chloramphenicol

The wide use of antibiotics in human therapy and veterinary practice has resulted in the presence of residual antibiotic compounds in water environments, which are harmful to ecology and health. In this work, novel hollow molecularly imprinted nanorods (HMINs) with uniform and controllable thickness of the polymer shell were successfully prepared via a combination of in situ surface precipitation polymerization and halloysite nanotubes sacrificial template method, and were used as an advanced selective nanoadsorbent to remove chloramphenicol (CAP). The physicochemical properties of HMINs were well characterized by FE-SEM, TEM, FT-IR and TG/DTA. HMINs with a shell thickness of 62 nm (HMINs-2) displayed excellent adsorption capacity and fast kinetics. The experimental adsorption equilibrium and kinetic data were best described by the Freundlich isotherm model and the pseudo-second-order rate equation, respectively. Furthermore, HMINs-2 possessed highly specific recognition to CAP in aqueous solutions, as compared with other reference antibiotics. Meanwhile, HMINs-2 also had excellent dispersibility, regeneration properties and thermal stability for the promising potential application in wastewater treatment.