Surface Imprinted Core-Shell Nanorod with Ultrathin Water-Compatible Polymer Brushes for Specific Recognition and Adsorption of Sulfamethazine in Water Medium

摘要

A surface imprinted core-shell nanorod with water-compatible property was first prepared, using a two-step "living" polymerization technique, with magnetic attapulgite (MATP) as core, and it was applicable in the enhanced selective removal of sulfamethazine residue from pure water environments. MATP was synthesized by an impregnation and pyrolysis method, and polymerable group was subsequently attached onto the surface. The imprinted polymer nanoshell (13 nm) with the "living" fragments was formed via a reverse atom transfer radical precipitation polymerization, avoiding the tedious graft of initiator and providing the easyaccessible imprinted sites. Ultrathin hydrophilic polymer brushes (2.0 nm) were surface-grafted to improve their water-compatibility. The nanoadsorbent exhibited good thermal stability, magnetism, and hydrophilicity through characterization. The nanoadsorbent showed large adsorption capacity toward sulfamethazine from water, which increased with the increase of contact temperature. Langmuir isotherm fitted the equilibrium data better, and the kinetic data (within 45 min) were well-analyzed by the pseudo-secondorder kinetic model. Also, the specific adsorption property of the nanoadsorbent was greatly improved through the surface-grafting, which exhibited excellent selectivity to sulfamethazine compared with other reference antibiotics. Efficient magnetic separation and good reuse of the nanoadsorbent provided the potential possibility for selective recognition and fast removal of antibiotic pollutions from water environments.