The nanocomposite particles (NPs) with inorganic silica as core and fluorinated polymer shell have been in situ synthesized via emulsion polymerization. The chemical composition and core-shell structure were characterized by Fourier-transform infrared spectrometry and transmission electron microscopy. The results showed that silica nanoparticles were encapsulated in latex particles, with single- and multicore morphologies coexisting. Thermal gravimetric analysis also suggested the successful encapsulation of silica into NPs with enhanced thermal stability. The surface properties of the latex films produced from the core-shell particles were also investigated by contact angle method and water absorption measurement. Both fluorinated polymer and silica contributed to less water absorption ratio and lower surface-free energy, which was composed of larger polar component and smaller disperse component, just reversed as usual. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115:3500-3507, 2010