Molecularly imprinted polymer with photocatalytic activity for ibuprofen adsorption, degradation, and detection in...

The aim of this investigation was to synthesize molecularly imprinted polymers (MIPs) with photocatalytic activity for the treatment of the emerging pollutant ibuprofen (IBU). The MIPs were synthesized by free radical polymerization; two different amounts of TiO₂ were used (25 %w and 5 %w), and the synthesis followed a non-covalent method. IBU was chosen as the target. The functional monomer and the crosslinker were 2-vinyl pyridine and ethylene glycol dimethacrylate, respectively. Non-imprinted polymers were synthesized. All samples were analyzed using high-performance liquid chromatography. Adsorption and photodegradation assays were performed using the photocatalytic MIP. TiO₂ does not affect the IBU adsorption capacity at concentrations below 20 ppm, however, the retention percentage is reduced at higher concentrations of TiO₂. The pseudo-second-order model best describes the adsorption kinetics. The Freundlich model fits the adsorption process for all materials; K_F is bigger for materials with 25 % TiO₂. In laboratory assays, complete degradation of IBU was achieved within 2.5 min using a MIP with 25 % of TiO₂. The presence of a possible degradation product is discussed. MIP/25 %TiO₂ was chosen to be tested with real samples; a concentration of 709 μg/L of IBU was found, and a degradation time of 10 min.