Synthesis of magnetic molecularly imprinted polymer particles for selective adsorption and separation of dibenzothiophene

We report on the synthesis of magnetic molecularly imprinted polymers (m-MIPs) for the selective adsorption and separation of dibenzothiophene (DBT) from oil solution. The m-MIPs were characterized by Fourier transform infrared analysis, transmission electron microscopy, surface area and porosity analysis, and vibrating sample magnetometry. Batch mode adsorption studies were carried out to investigate the adsorption kinetics, adsorption isotherms and selective recognition. The adsorption kinetics were modeled with the pseudo-first-order and pseudo-second-order kinetics, and the adsorption isotherms were fitted with Langmuir and Freundlich models. The m-MIPs can selectively recognize DBT over similar compounds. Static adsorption experiments showed that the m-MIPs display excellent recognition capacity, selective affinity for DBT, and superparamagnetism in presence of an external magnetic field. TEM images of the Fe 3 O 4 (A), Fe 3 O 4 @SiO 2 (B), Fe 3 O 4 @SiO 2 @MIPs (C) and (D). The morphology of Fe 3 O 4 , Fe 3 O 4 @SiO 2 , Fe 3 O 4 @SiO 2 @MIPs was observed by TEM. As can be observed in Fig. 2, the Fe 3 O 4 magnetic nanoparticles (Fig. 2a) had a diameter in the range of 8–16 nm, which indicated the prepared magnetic nanoparticles were superparamagnetic. It could be found from Fig. 2b and c, 2D that all samples displayed spherical shape before and after being encapsulated by silica and MIP. There are significant layers present on the surface of Fe 3 O 4 @SiO 2 , which indicated MIP has been successfully prepared.