Chitin/graphene oxide composite films with enhanced mechanical properties prepared in NaOH/urea aqueous solution

Chitin/graphene oxide (GO) composite films with excellent mechanical properties were prepared in NaOH/urea solution using a freezing/thawing method. The structure, thermal stability and mechanical properties of the composite films were investigated. Use of an atomic force microscope and transmission electron microscopy indicated that GO was successfully exfoliated to a single layer by ultrasonication. The results revealed that GO nanosheets were homogeneously dispersed and embedded in the chitin matrix. Due to the strong interactions between GO and the chitin matrix, the tensile strength and elongation at break of the composite film possessing 1.64 wt% GO were significantly improved by 98.7 and 114.5 %, respectively, compared with pure chitin film.