Effect of graphene oxide on the solution rheology and the film structure and properties of cellulose carbamate

Highly ordered, homogeneous and reinforced cellulose carbamate (CC)/graphene oxide (GO) composite films were prepared using an easy, aqueous and solution-mixing method. The dynamic rheology measurement showed that the addition of 2 wt.% GO decreased the complex viscosity of CC solution and significantly prolonged the valid spinning time of CC solution. X-ray diffraction characterization revealed that GO promoted the transition of crystalline structure of CC from cellulose I to II, and the addition of 2 wt.% GO improved the orientation and crystallinity of the CC molecules. Scanning electron microscope images indicated that the GO layers were aligned parallel to the surface of the composite films. The incorporation of GO also showed profound effects on the macroscopic properties of the CC film. Compared to the pure CC, the composite showed a 280% increase in Young's modulus and 180% increase in tensile strength by the addition of 2 wt.% of GO. Moreover, the carbon yields of all the composite films were higher than that of pure CC film.