Stable cellulose/graphene inks mediated by an inorganic base for the fabrication of conductive fibers

Graphene-based conductive fibers with superior mechanical and electrical performance have been highly desirable due to their great application potential in the field of wearable electronic devices. However, achieving a uniform dispersion of graphene in the polymer matrix is still a big challenge, especially under aqueous system conditions. Here, we proposed an inorganic base-mediated strategy to disperse graphene in aqueous cellulose solution by simple mechanical stirring without any surfactants, and prepared stable cellulose/graphene aqueous inks. We demonstrated that the inorganic metal-ions adsorbed on the graphene surface as well as the steric hindrance effect of cellulose chains could effectively prevent the π-π stacking of nanosheets. The obtained inks have shown good stability for several weeks and could be directly used to produce conductive fibers through wet-spinning technology. Experiments and molecular simulations have both revealed that the uniformly dispersed graphene nanosheets could simultaneously improve the strength and toughness of the fibers. Combined with electrical conductivity, the fibers have also shown promising application potential in the fields of respiratory rate monitoring and electromagnetic shielding fabrics. Therefore, this inorganic base-mediated dispersion strategy here may open up a new general path for the low-cost and environmentally friendly aqueous processing of high-performance graphene-based composites. The schematic diagram of the dispersion mechanism of graphene and preparation of conductive fibers.