Synthesis and characterization of dibenzothiophene imprinted polymers on the surface of iniferter-modified carbon microspheres

Abstract

Molecularly imprinted polymers (MIPs) on the surface of iniferter-modified carbon microspheres (CMSs) were synthesized by using dibenzothiophene (DBT) as the template molecule, methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the crosslinker. The influencing factors of monomer-grafting process were investigated. The characterizations of structure and morphology suggest that a thin layer of MIPs was grafted on the surface of CMSs under the optimized conditions. The adsorption results show MIPs-CMSs possessed higher binding capacity and selectivity than non-imprinted polymers on CMSs (NIPs-CMSs), and exhibited a good competitive adsorption capacity for DBT. The maximum adsorption capacity of MIPs-CMSs towards DBT reached 88.83 mg g−1. In addition, the adsorption of DBT on MIPs-CMSs follows Langergren pseudo second order model and Langmuir–Freundlich isotherm. Negative values of the Gibbs free energy, positive values of standard enthalpy and entropy reveal that the adsorption was a spontaneous, endothermic and entropically driven process during 288–318 K. From the regeneration experiments and adsorption results in the real oil, it is concluded that the MIPs-CMSs could be used in deep desulfurization of fuel oils.