Molecular Simulation And Adsorption Mechanism Of Carbamazepine Imprinted Adsorbent

Molecular simulation can provide valuable theoretical guidance for rapid selection of functional monomers in imprinted adsorbents. The recognition systems were constructed , which consisted of targeted pollutant carbamazepine (CBZ) as template molecule and 14 functional monomers respectively. The low-energy conformations of template-monomer interaction system were searched by simulated quenching method. This method overcame the shortcoming of the existing searching method by which the conformations were prone to fall into local potential wells. Molecular simulation indicated that the binding capacity of itaconic acid (IA) as monomer to CBZ was the strongest. Adsorption experiments showed that IA-prepared imprinted adsorbent (IA-MIP) performed better than the adsorbent prepared by traditional monomer methylacrylic acid. The adsorption capacity of IA-MIP could reach 9. 28 mg/g in aqueous solution. IA-MIP also showed high selectivity to carbamazepine in filtration effluent. After 10 reuses , the adsorption capacity decreased by only 1. 3% . The ultraviolet spectra of the imprinted system were calculated theoretically and measured. The experimental results confirmed that a new interaction system was formed between IA and CBZ. Molecular simulation could predict the ultraviolet spectra of IA and CBZ in aqueous solution very well. However, the prediction of the ultraviolet spectra of the interaction system was not ideal, which suggested that there existed a variety of interaction conformations during the specific adsorption process. Energy calculation and hydrogen bond analysis demonstrated that van der Waals and electrostatic force played a major role in the recognition process. Infrared analysis confirmed the existence of hydrogen bond in the system, and the recognition site was located between the carboxylic group of IA and carbamazepine amide , which was consistent with the results of molecular simulation.