With the sol-gel method, the regenerated SF (silk fibroin)/nano-TiO₂ composite films were synthesized using different ratios of SF to TiO₂. The experimental results reveal that the nano-TiO₂ particles were well dispersed in the regenerated silk fibroin. The diameter of nano-TiO₂ particles was about 80 nm by UV and AFM. Through FTIR, XRD, EDS, TGA and DTG, the structures and properties of these films were characterized. The XRD measurement indicated that the crystal structures of the composite films were transited from typical Silk I to typical Silk II. However, it was found that the excessive increase in the content of nano-TiO₂ led to the breakage of the crystal structures of the composite films. The FTIR and EDS analysis showed that new bonds were formed between the nano-TiO₂ particles and the silk fibroin. Through TGA and DTG, it was demonstrated that the heat transition temperature of composite films was also enhanced.

Key words: silk fibroin, nano-TiO₂, crystal form, heat transition