MOLECULAR CONFORMATION OF Bombyx mori SILK FIBROIN OBTAINED BY DIFFERENT CASTING CONDITIONS

Abstract

In order to elucidate the molecular conformation and the morphology of silk fibroin obtained by casting from an aqueous silk fibroin solution, infrared spectroscopic and scanning electron microscopic observations were done. The lower the casting speed, the more the silk fibroin molecules gave a beta-rich conformation even if the casting temperature is high. The higher the casting speed, the more the silk fibroin molecules gave a random coil-rich form, indicating that the molecular conformation chiefly depends on the casting temperature and also on the casting speed. The optimum temperature for obtaining the spherulites from the silk fibroin solution (0.4%) was found to be about 25°C.