An ion-imprinted composite membrane using microporous polypropylene An ion-imprinted composite membrane, with microporous polypropylene membrane (MPPM) as support, was prepared by a modified UV-induced graft copolymerization. In the graft strategy, photoinitiators were immobilized on the surface of MPPM by combining the physical entrapment and UV-induced covalent immobilization methods. The effects of preparation conditions on grafting amount of ion-imprinted polymer were discussed. The distributions of ion-imprinted polymer on the surface and cross-sectional of the composite membrane were analyzed by field emission scanning electron microscopy-energy dispersive X-ray spectroscopy (FESEM-EDX). Static water contact angle and pure water flux measurements were also conducted. Results show that the imprinted composite membranes have satisfactory surface hydrophilicity and penetrability, and the pure water flux is up to 2077  77 L/m2h. The regeneration experiments indicate that, the ion-imprinted composite membranes have favorable regeneration performances. After ten adsorption-desorption cycles, adsorption capacity and selectivity coefficients of the ion-imprinted composite membranes can maintain more than 90% and 80%, respectively.