A series of polysiloxane/TiO2 composite films was prepared through in-situ hydrosilylation reaction of vinyl-terminated silicone oil and hydrogen silicone oil in the presence of anatase titanium sol particles or P25 type TiO2 powder particles

in order to achieve a homogeneous dispersion of TiO2 particles in the cross-linked substrate films.The chemical composition

cross-linking structure

morphology

tensile and optical properties of the composite films were characterized by attenuated total reflection Flourier transformed infrared spectroscopy

field emission scanning electron microscopy

transmission electron microscopy

tensile tests

and UV/Vis spectroscopy.The stability of reaction system and the tensile property of the composite films were improved because of the chain extension of silicone oil and the reinforcement of SiO2.Hydrophilic TiO2 powder particles were easy to form macro-aggregates during the process of film formation.The agglomeration of TiO2 powder particles had negative influence on the mechanical and optical properties of the composite films.The surface of titanium sol particles prepared via a sol-gel process displayed lipophilicity as a result of the remaining of organic groups.The lipophilic surface of titanium sol particles improved the compatibility between titanium sol particles and polysiloxane.Titanium sol particles with a lipophilic surface could be uniformly dispersed in toluene and composite films without agglomeration.The resultant polysiloxane/titanium sol composite films showed good tensile properties

strong UV shielding and high transparency.