A new template membrane, acrylic acid grafted microporous polypropylene (PP) membrane, was prepared using the supercritical (SC) CO2 as a solvent. Then zinc ions were anchored in the membrane by forming a monodentate complex with the carboxyl groups in the template membrane. Subsequent treatment with Na2S aqueous solution led to the formation of ZnS nanoparticles within the PP matrix, resulting in ZnS/PP nanocomposite. UV-Vis and Fourier Transform Infrared (FTIR) spectra, and energy-dispersive X-ray analysis (EDS) confirmed the existence of ZnS in the grafted membrane. Field emission scanning electronic microscopy (FE-SEM) and transmission electron microscopy (TEM) images showed that the ZnS nanoparticles distributed uniformly in the composite. (C) 2003 Elsevier B.V. All rights reserved.