Development of functionalized nanostructured polymeric membranes for water purification

Pharmaceuticals specific molecularly imprinted polymers nanoparticles (MIPNPs) were synthesized and applied onto the polyvinylidene fluoride (PVDF) membranes previously subjected to the plasma treatment. Diclofenac-, metoprolol- and vancomycin-MIPs were applied onto the membranes and scanning electron microscopy was employed to visualize MIPNPs on the membrane. After functionalization of the membranes with target-specific MIPs the molecularly imprinted membranes (MIMs) affinity against their targets was evaluated using solid phase extraction (SPE) technique coupled with high performance liquid chromatography (HPLC). MIMs were used as filters to load the target solutions through employing a vacuum pump to evaluate the amount of pharmaceuticals in filtrate. Moreover, a comparative study was performed by comparing the efficiency of MIMs functionalized either by adsorption or covalent immobilization. The capacity analysis of MIPNPs by SPE–HPLC revealed 100%, 96.3%, and 50.1% uptake of loaded solution of metoprolol, diclofenac and vancomycin, respectively. MIMs showed 99.6% uptake with a capacity of 60.39 ng cm2 for metoprolol; 94.7% uptake with a capacity of 45.09 ng cm2 for diclofenac; and 42.6% uptake with a capacity of 16.9 ng cm2 for vancomycin. HPLC detection limits of targets were found as 3.7, 7.5 and 15 ng mL−1 for diclofenac, metoprolol and vancomycin respectively. A small scale pilot test was also conducted which indicates the promising future applications of the developed MIMs for high volume of filtrates especially in the case of the plasma-treated PVDF membranes prepared by covalent immobilization of the MIPs.