Preparation and structure of porous silk sericin materials

Porous materials of Bombyx mori silk sericin were prepared by freeze-drying. The effects of concentration of the sericin solution and that of freezing temperature on the structure and properties of materials were investigated. The results indicated that porous sericin materials, with average pore radius between 60 and 90 mu m and porosity between 75 and 85%, could be prepared by freeze-drying. Thicker solution and lower freezing temperature resulted in smaller pore radius and porosity and moreover, bigger pore density. The condensed structure of interior sericin was mainly amorphous, and contained some crystal structure. Compared to the non-crosslinked porous sericin materials, the content of the beta-sheet structure of the sericin materials, cross-linked by poly(ethylene glycol) diglycidyl ether, increased to some extent.