Silk fibroin (SF) thin film was prepared via colloid chemical routes (CC) and by pulsed laser deposition (PLD).
Secondary structure of the CC film, as examined by FT-IR, was random coil. By a post treatment with methanol, it
transforms to b-sheet. As for PLD films, the b-sheet structure of SF powder was mostly preserved as deposited. This
suggests that the post treatment is effective to restore the original b-sheet structure in the thin films. Transformation from
random coil to b-sheet is easier in the film on the substrate of polyethylene than Si(1 0 0) due to weaker affinity to silk
secondary structure , Silk fibroin (SF) , Post treatment , b-sheet