Effect of cross-linkable bacterial cellulose nanocrystals on the physicochemical properties of silk sericin films

Abstract

The manufacture of eco-friendly cocoon silk-derived sericin films increases the availability of sericulture resources and the interest in expanding the range of the potential applications of sericin-based materials. However, the brittleness and weak tensile properties of sericin and its vulnerability to moist environments have limited its use. To overcome these two shortcomings of sericin, a functionalized bacterial cellulose-derived nanocrystal (average diameter: 25.4 nm) capable of physical strengthening and chemical crosslinking on existing sericin films was prepared. The improvement of the optical, physicochemical, and mechanical properties of the sericin film was observed through the dialdehyde bacterial cellulose nanocrystals (D-CNCs) incorporated into the silk sericin (SS) matrix. The physical reinforcing effect of the D-CNCs on the SS films enhances the mechanical properties of the films. Simultaneously, the chemical crosslinking reaction of D-CNCs develops the ultraviolet-blocking, water-resistant, and antioxidant properties of the films. The simultaneous fabrication, physical reinforcement, and chemical crosslinking of the SS/D-CNCs biocomposite film produced using an aqueous solution will provide information on the functionalization and performance improvement of water-soluble biopolymeric materials, especially hydrophilic protein resources.