Preparation and characterization of transparent silk fibroin/cellulose blend films

Both silk fibroin (SF) and cellulose are considered as potential substitutes of synthetic polymers because of the problems for the exhaustion of fossil resources and the pollution of environment. In order to obtain a material that exhibits both the advantages of SF and cellulose, ionic liquid (IL) was introduced to prepare blend films of SF and cellulose in the present work. We found that by our new fabricate method, i.e. coagulating SF/cellulose IL mixture solution by vapored methanol and cold pressing during vacuum dry, the resulted SF/cellulose blend films were transparent owing to the significant compatibility between cellulose and SF. The mechanical properties of the blend films in dry state is better than other reported counterparts, while those in wet state is good enough for further applications. Our results also confirms that the miscibility of SF and cellulose was induced by the intermolecular interactions between the components in the same blend system but with different fabricating methods in the literature. In addition, mouse fibroblast L929 cells was found to show the significant adhesion and proliferation on the blend film, which suggested that the treatment of IL and methanol may not affect the biocompatibility of SF/cellulose blend films. (C) 2013 Elsevier Ltd. All rights reserved.