抄録
We used scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetry (TG) to examine the physical properties of tussah silk fibroin (TSF) nanofibers prepared from the Antheraea pernyi silkworm by using an electrospinning procedure. TSF nanofibers spun from TSF trifluoroacetic acid (TFA) solution possessed an α-helix and random coil conformations and did not take on a β-sheet structure. The TSF nanofibers showed specific FTIR absorption bands at 1199, 1175, 1135, and 1049 cm-1, presumably because of the trace of TFA present in the sample nanofibers at a molecular level. TSF nanofibers showed no clear molecular structural changes upon heat treatment at about 160 °C for 1 h. However, methanol/water vapor annealing crystallized the TSF nanofibers, which clearly changed from randomly coiled conformation to a β-sheet structure. A minor endothermic peak at about 172 °C on the DSC curve of the TSF nanofibers was attributable to removal of TFA from the nanofibers; this peak disappeared after heat treatment at 160 °C for 1 h.
