High-Performance Cellulose Nanofibers/Carbon Nanotubes Composite for Constructing Multifunctional Sensors and Wearable Electronics

Abstract

The green preparation of highly dispersed carbon nanotube (CNT) conductive inks remains a critical challenge in the field of flexible electronics. Herein, a waterborne CNT dispersion approach mediated by carboxylated cellulose nanofibers (C-CNFs) was proposed. CNFs, special biomass materials with excellent nanostructures and abundant active surface groups, are used as green dispersants. During the dispersion process, benefiting from chemical charge and dimensional matching, C-CNF/CNT wicking-driven stable composite structures (CCNTs) were co-assembled via hydrogen bonding, electrostatic stabilization and π–π stacking between the interfaces, generating controlled orientational structures and promoting stable dispersion and conductivity of CNTs, which were demonstrated via molecular dynamics simulations combined with a variety of physicochemical characterization methods. The dispersion concentration of CNTs in a CCNT slurry can reach 80 wt%, and the obtained CCNT slurry has a low zeta potential (less than − 60 mV) and good stability. Due to the film-forming properties of CNFs and in-plane oriented self-assembly of CCNT, the composite self-supporting films were fabricated with high electrical conductivity (67 S cm⁻¹) and mechanical performance (tensile strength of 153 MPa). In addition, the resulting biobased CCNT ink is compatible with a variety of printing processes and adaptable to various substrates. Moreover, this ink can be used to construct multifunctional advanced sensors with electrochemical, electrothermal, and deformation/piezoresistive responses, which demonstrate excellent performance in monitoring human health.

Graphical Abstract