Highly selective removal of 2,4-dinitrophenol by a surface imprinted sol-gel polymer

摘要

In this work, 2,4-dinitrophenol (2,4-DNP), a new molecularly imprinted polymer (MIP) with excellent performance was synthesized in ethanol by the sol-gel method using 3-aminopropyltriethoxysilane as functional monomer on the surface of silica particles. The structure and morphology of MIP were characterized via scanning electron microscopy, nitrogen adsorption-desorption analysis, infrared spectra, and thermogravimetry analysis. Results demonstrated that MIP had excellent selectivity toward the template molecule (2,4-DNP) with an imprinting factor of 9.55 and a maximum static adsorption capacity of 114.7 mg g(-1). Data obtained from the adsorption isotherm of 2,4-DNP were fitted well with the Freundlich isotherm model, and the adsorption process can be described by the pseudo-second-order model. The investigation of adsorption mechanism revealed that the specific recognition process of MIP toward 2,4-DNP was dominated by the hydrogen bond and molecular structure. By employing as a sorbent, the as-prepared MIP was applied to recognize and remove 2,4-DNP in poster paper, nonwoven fabric and brown curtain with recoveries in the range from 85.74 to 100.00%. However, the MIP can effectively remove 2,4-DNP after five cycles.