Abstract: In this work, atrazine functions as a template molecule, and trifluoromethacrylic acid (TFMAA), methacrylic acid (MAA), methyl methacrylate (MMA), and acrylamide (AM) serve as functional monomers, respectively. By using density functional theory (DFT), the computational approach was carried out to simulate the self-assembly system of template and functional monomer. The geometry optimization, action sites, binding energies, and molecular imprinting mechanism of complexes with different functional monomers in different proportions were predicted. The simulation results showed that atrazine and the functional monomers interacted through hydrogen bond. Among the 4 functional monomers, the imprinted complex formed by TFMAA and atrazine with a ratio of (1:6) has the lowest binding energy and the best imprinting effect. Then, the microspheres of molecularly imprinted polymer (MIPs) were prepared by precipitating polymerization using atrazine as the template molecule and TFMAA as the functional monomer. The microspheres were observed by scanning electron microscopy (SEM). The results showed that atrazine MIP microspheres had average particle size of 400 nm, which was greater than the non-imprinted polymeric microspheres (NIPs). Dynamic adsorption experiments of MIPs showed that the adsorption reaction reached balance after 200 min. Analysis of the Scatchard plot revealed that the binding sites of MIPs to atrazine were equal class under the studied concentration range. The dissociation constant (Kd) and apparent maximum adsorption quantity (Qmax) of MIPs were 3.6 x 10-5 mol/L and 4.83 μmol/g, respectively. The study of selective adsorption between atrazine and metribuzin showed that imprinted microspheres had high selectivity for the template molecule atrazine.
Template and target information: atrazine
Author keywords: atrazine, molecular imprinting, Trifluoromethacrylic acid, computer simulation