Preparation and properties of double template molecularly imprinted polymers with phthalate isomers

Abstract:

To efficiently remove phthalates (PAEs) from liquid, di(2-ethyl)hexyl phthalate (DEHP) was used as template molecule, di-n-octyl phthalate (DNOP) as auxiliary template molecule, silicon dioxide modified magnetic nano-ferric tetroxide (Fe₃O₄@SiO₂) as carrier, alpha-methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as crosslinking agent, and azodiisobutyronitrile (AIBN) as lead in this experiment. The bulk thermal initiation polymerization method was used to prepare double template molecularly imprinted polymers (D-MIPs) which had better adsorption performance than traditional single template molecularly imprinted polymers and could adsorb both target substances simultaneously. The specific adsorption, selectivity, and regeneration of D-MIPs were studied in detail. Results show that the introduction of the DNOP auxiliary template molecule could optimize the adsorption performance of DEHP. The unit adsorption capacity of D-MIPs for 10 DEHPs with different concentrations ranged from 0.49 mg/g to 6.16 mg/g, and the unit adsorption capacity and adsorption rate of D-MIPs were both superior to those of DEHP-MIPs. There were multi-site synergies between the two template molecules and the selected monomer, and D-MIPs could reach the optimal adsorption equilibrium state in 30 min. The adsorption capacity at the fifth time was 84.02% more than that at the first time, and it had good regeneration performance. Static adsorption process fitting indicates that the polymer system was more consistent with the single layer specific adsorption Langmuir adsorption model. The adsorption of D-MIPs and DEHP-MIPs on the target molecules was in accordance with the pseudo-second-order kinetics process. FT-IR infrared spectroscopy on the imprinted polymer characterization of the functional groups confirmed that the polymerization effect was good.