Preparation and characterization of cellulose nanocrystal-carbon nanotube/ polyvinyl alcohol composite conductive membranes with oriented fibers by electrospinning

Carbon nanotubes (CNTs) which were carried by cellulose nanocrystals (CNCs) were used to form the uniform CNCs-CNTs conductive complexes in the aqueous phase. The homogeneous spinning solution was prepared by dispersing CNCs-CNTs complexes evenly in polyvinyl alcohol (PVA) matrix. The CNCs-CNTs/PVA conductive composite membranes which consisted of oriented fibers were prepared by electrospinning. The results indicate that CNCs-CNTs complexes can efficiently enhance the thermodynamic properties of the fiber membrane and endow it with conductive function. The orientation of the fibers can significantly improve the mechanical properties of the membrane. With the increasing of CNTs content, the conductivity and viscosity of the spinning solution are increasing while the fiber diameter is decreasing. When the mass ratio of CNCs and CNTs to PVA are 8.0% and 1.0%, the fiber diameter, tensile strength and the conductivity are 182 nm±35 nm, 15.99 MPa±1.25 MPa and 0.12 S/m±0.01 S/m, respectively, for CNCs-CNTs/PVA membranes. The specific capacitance can reach 127.1 F/g at the current density of 0.2 A/g, and it can maintain 83.14% of its initial capacity after 1 500 constant-current charge/discharge cycles. Based on its excellent mechanical strength, thermostability and electrical conductivity, the as-prepared CNCs-CNTs/PVA conductive membrane is expected to be used as foldable supercapacitors, flexible sensors and electrode materials. © 2018, Editorial Office of Acta Materiae Compositae Sinica. All right reserved.