Preparation of Silk Fibroin/Pearl Powder Blend Films

Abstract

Silk fibroin (SF) / pearl powder (PP) blend films with glycerol as a crosslinker were prepared by adding PP into SF solution and casting the SF solution onto the polystyrene disks at room temperature. The effects of amount of PP on surface morphology, structure, mechanical properties and water-solubility of films were investigated in this study. The surface morphology was observed with scanning electron microscope. The structure of films was investigated by X-ray diffraction. The dissolution rates of SF in films were measured by ultraviolet spectroscopy and mass loss percentages of the films were examined by weighing method. The elongation at break and the tensile strength of the films were measured on a universal testing machine. The results showed that surface of films without PP was smooth, particles rose increasingly obviously on the surface of films with PP with the increase of amount of PP. The condensed structure of SF in the films without PP was mainly silk I crystals. When the addition of PP was more than 5%, it had obvious effects on the crystal formation of SF in the films. Apart from silk I crystals, silk II crystals formed in the condensed structure of SF containing PP. The mass loss rate of films decreased with the increase of PP and the corresponding dissolution rate of SF was between 0.29% and 0.48% when the proportion of PP was in the range of 0% to 15%. The elongation at break was significantly affected by the addition of PP, but there were no significant effects on the tensile strength. When the proportion of PP was more than 5%, the elongation at break of the films dropped significantly.