Effect of cellulose solubility on the thermal and mechanical properties of regenerated cellulose/graphene nanocomposites based on ionic liquid 1-allyl-3-methylimidazoliun chloride

Regenerated cellulose/ionic liquids (ILs)-reduced graphene oxide (IRGO) nanocomposites have been prepared via a simple and green method based on 1-allyl-3-methylimidazoliun chloride (AmimCl). To one's surprise, it is found that the presence of a small amount of IRGO sheets can largely decelerate the dissolution of cellulose in AmimCl, and thus the thermal and mechanical properties of resultant cellulose/IRGO nanocomposites could be controlled simply by changing the dissolution time. Our results suggest that the residual cellulose fibrils with micrometre size are beneficial to the thermal stabilities of regenerated cellulose/IRGO films when short dissolution time is used. However, for obtaining cellulose/IRGO nanocomposites with improved mechanical properties, full dissolution and mixture of cellulose in IRGO/AmimCl solution with prolonged time are required. Compared with the regenerated pure cellulose film, our cellulose/IRGO nanocomposite prepared with dissolution time of 4 h exhibits about 23 degrees C increase in decomposition temperature, and 10.7% increase in tensile strength and remarkably 387.5% increase in strain at break, respectively.