In this study, poly(vinylidene fluoride-co-chlorotrifluoroethylene)-graft-poly(oxyethylene methacrylate), P(VDF-co-CTFE)-g-POEM, an amphiphilic comb copolymer with hydrophobic P(VDF-co-CTFE) backbone and hydrophilic POEM side chains at 73:27 wt % was synthesized. The POEM side chains were grafted from the P(VDF-co-CTFE) mainchain backbone via atom transfer radical polymerization (ATRP) using direct initiation of the chlorine atoms in CTFE units. Synthesis of microphase-separated P(VDF-co-CTFE)-g-POEM comb copolymer was successful, as confirmed by nuclear magnetic resonance (H-1 NMR), FTIR spectroscopy, and transmission electron microscopy (TEM). Nanocomposite films were prepared using the comb copolymer as a template film and the in situ reduction of AgCF3SO3 precursor to silver nanoparticles under UV irradiation. Silver nanoparticles with 4-8 nn in average size were in situ created in the solid state template film, as revealed by TEM, UV-visible spectroscopy, and wide angle X-ray scattering (WAXS). Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) presented the selective incorporation and the in situ growth of silver nanoparticles within the hydrophilic POEM domains of microphase-separated comb copolymer film.(C) 2008 Wiley Periodicals, Inc.