Preparation of MWCNTs-Graphene-Cellulose Fiber with Ionic Liquids

Abstract

The conductive multiwalled carbon nanotubes (MWCNTs)-graphene sheets (rGOs)-cellulose fiber was prepared with an eco-friendly wet-spinning method in which ionic liquid (IL) was used as both green solvent and dispersant. It was found that the selected IL 1-ethyl-3-methylimidazolium diethyl phosphate (EmimDep) shows remarkable capacities for dissolving cellulose and dispersing MWCNTs, and the synergistic effect of MWCNTs, rGOs, and cellulose results in a high electrical conductivity of 1195 S/m of MWCNTs-rGOs-cellulose fibers. Macropores and the double-layer structure of MWCNTs and rGOs can be observed by SEM in the studied fibers, and the number of macropores decreased with increasing rGOs amount, which is consistent with the result of the specific surface area. In addition, the prepared MWCNTs-rGOs-cellulose fibers present a nearly perfect electrical double-layer structure. The MWCNTs-rGOs-cellulose fiber with a mass ratio of 2:3:1 shows the best performance as the electrode candidate, with an electrical conductivity of 1195 S/m, specific capacitance of 597 mF/cm2, and specific surface area of 91 m2/g. Furthermore, the results from the molecular dynamics (MD) simulation evidenced that EmimDep can disperse CNTs effectively at 363.15 K, 1 atm compared to rGOs; the synergy effect of CNT and rGO exhibit great potential to enhance the dispersion than each individual component.