A deep insight for TBBPA imprinting on PVP-assisted separation membrane: Elucidation of detailed chemical transition in membrane preparation and imprinting process

Given that the widespread existence of Tetrabromobisphenol A (TBBPA) in water can cause severe hazard to human health and the eco-environment, it is imperative to develop an eco-friendly functional material with precise capture and separation capacity towards TBBPA. Herein, we found a feasible route to achieve above purpose by preparing TBBPA-molecularly imprinted membranes (TB-MIMs). Polyvinylpyrrolidone (PVP) with different amounts were firstly blended into the membrane substrate to adjust the pore size and endow the membrane surface with convertible functional groups and hydrophilicity, followed by the modification via gallic acid and VTMOS. Subsequently, the click chemistry was finally employed to engineer the imprinting sites of TBBPA. The membrane incorporated with 7 wt% of PVP exhibited significantly enhanced water flux (196 L m^-2h⁻¹), water contact angle (78.6 ± 2.2°) and porosity (75.4%) than that of other membranes with different additive amounts of PVP, which was appropriate for the follow-up imprinting process. TB-MIMs exhibited comparable permeation selectivity containing interferents (3.72 for BPA, 3.86 for BP, 3.92 for BBPA), which was far superior to the TB-NIMs. The chemical transition and structural evolution over preparation and adsorption process were systematically investigated through in situ FTIR spectra and DFT, which proven the feasibility of strategy. It is worth noting that the resulting TB-MIMs showed a remarkable stability in various chemical environments and long-term stability in continuous operation process, which showed great promise in practical application.