Thin layer molecularly imprinted composite membranes for selective separation of erythromycin from water

Abstract

Molecularly imprinted composite membranes for selective binding of erythromycin were synthesized by UV initiated photo-copolymerization using polysulfone ultrafiltration (PSF) membranes as porous supports. The thin imprinted layers deposited on the surface of the support membranes were formed by copolymerization of acrylic acid (AA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as cross-linker in the presence of erythromycin as template molecule in acetonitrile solution. Fourier transform infrared spectroscopy (FT-IR) was used to study the binding mechanism between the imprinted sites and the template. Scanning electron microscope (SEM) was utilized to visualize surface and cross-sections of membranes to gain better understanding in the analysis of imprinted layers deposited on PSF support membranes. The modification degrees for imprinted and nonimprinted membranes are 2.04 and 2.15 mg/cm2, respectively. Static equilibrium binding and recognition properties of the imprinted and nonimprinted membranes to erythromycin (EM) and its analogue roxithromycin (RM) in aqueous system were tested. The results showed that saturated binding capacity of imprinted membranes to erythromycin was about 0.185 mg/cm2, nearly eight times that of nonimprinted ones, and the selectivity factor of αEM/RM was 3.24. The results of this study implied that the synthesized molecularly imprinted composite membranes could be used as selective separation materials for erythromycin enrichment from water.