A solvothermal process was developed to in situ prepare epoxy (EP)/TiO2 hybrid precursors. The chemical structure of samples was confirmed by X-ray and Fourier transformed infrared spectroscopy. Field emission scanning electron microscope micrographs of cured EP/TiO2 hybrid composites showed that well-dispersed TiO2 nanoparticles were successfully in situ formed in epoxy matrix through the solvothermal process. The thermogravimetic analysis, DSC, and gel content measurements showed that EP/TiO2 hybrid precursors were fully cured with the glass transition temperature decreasing gradually. The effect of TiO2 contents on optical and surface properties was investigated in detail. The results indicated that epoxy/TiO2 nanocomposites exhibited excellent UV shielding effect and high visible light transparency. The contact angle of EP/TiO2 nanocomposites, when the content of silane-coupling agent (KH560) was 5 g and the content of tetrabutyl titanate (TBT) was 3 g, can reach as high as 101 degrees, which was 36 degrees higher than that of pure EP, representing for the increase of hydrophobicity. (c) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012