Theoretical calculation guided molecularly imprinted polymer for selective adsorption of phloroglucinol

Effective adsorption of phloroglucinol (PG) is a method that kills two birds with one stone, which can not only reduce the harm of phenolic wastewater to the environment but also bring considerable economic benefits. In this work, the optimal functional monomer N-Vinyl imidazole (VIM) that possesses the strongest affinity with PG among 11 phenolic monomers was quantitatively selected by DFT calculation. The key factors that influence the adsorption capacity (Qe) and imprinting effect (& alpha;) were systematically researched. And the physicochemical property and morphology of the obtained VIM-MIP with the best adsorption performance were explored by a series of characterization methods. The adsorption tests were carried out, indicating that the VIM-MIP exhibited a large adsorption capability (Qe = 81.34 mg/g), which exceeded 78.97 % of the existing optimal absorbents for PG. What's more, the adsorption data for PG fit in with the Freundlich model (R2 > 0.99). More notably, the excellent PG selectivity of the VIM-MIP was confirmed by competitive adsorption experiments under binary systems (relative selectivity coefficient, 2.014), which was attributed to the existence of imprinted cavities. The molecular simulation, X-ray photoelectron spectroscopy (XPS) analysis, and Zeta potential analysis were employed to reveal the adsorption mechanism, indicating the hydrogen bond was the main driving force.

Automated summary

In this study, the optimal functional monomer VIM was quantitatively selected by DFT calculation, which exhibited the strongest affinity for PG among 11 phenolic monomers. The physicochemical property and morphology of the obtained VIM-MIP with the best adsorption performance were explored, and the adsorption mechanism was revealed to be driven by hydrogen bonding. The VIM-MIP showed a large adsorption capability for PG and excellent selectivity in binary systems.