Property enhancement of graphene fiber by adding small loading of cellulose nanofiber

Herein, a small amount of cellulose nanofiber (CNF) was introduced in graphene oxide (GO) spinning dope to improve the property of graphene fiber. It was found that the one-dimensional CNF could absorb on the GO sheets, and enhance the inter-layer interaction as well as the connection between GO sheets, resulting in an easy formation of lyotropic liquid crystalline structure and a better orientation of the resultant fiber. A large enhancement of tensile strength, modulus, and elongation of GO/CNF hybrid fiber has been achieved. After chemical reduction of GO, the fiber still maintains its original mechanical properties but with high conductivity and improved hydrophilicity. Our work further demonstrates the importance of a stable lyotropic liquid crystalline structure of GO dope in the spinning of graphene fiber and provides a facile way to produce graphene fiber with good performance.