Enhancing Mechanical Properties of Flexible Graphene/ Cellulose Conductive Paper by Chemically Modifying Cellulose Fibers.

In recent years, conductive paper made of graphene and cellulose fibers has triggered a great deal of attention due to its scalable fabrication process, low cost, and environmentally friendliness. However, poor mechanical properties limit its commercial applications. In this study, conductive graphene/cellulose paper with improved elastic modulus and desirable conductivity was achieved by chemically modifying the surface properties of natural cellulose fibers using aqueous 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidation system. The effect of the carboxyl content on the mechanical properties and conductivity of graphene/cellulose paper was studied in detail. The results showed that the carboxyl content of cellulose had a significant impact on the mechanical properties of graphene/cellulose paper. At low carboxyl content (0.42 mmol/g), the elastic modulus of the graphene/oxidized-cellulose conductive paper achieved the value of 1572 MPa, which was 27.4% larger than that of cellulose/graphene conductive paper. Meanwhile, the as-prepared paper exhibited excellent conductive properties, and its sheet resistance was only 78.57 Ω/sq.