Highly Conductive Ink Based on Self‐Aligned Single‐Walled Carbon Nanotubes through Inter‐Fiber Sliding in Cellulose Fibril Networks

Abstract

AbstractCarbon nanotubes (CNTs), owing to their superior electrical and mechanical properties, are a promising alternative to nonmetallic electrically conducting materials. In practice, cellulose as a low‐cost sustainable matrix has been used to prepare the aqueous dispersion of cellulose‐CNT (C‐CNT) nanocomposites. However, the compatibility with conventional solution‐processing and structural rearrangement for improving conductivity has yet to be determined. Herein, a straightforward route to prepare a conductive composite material from single‐walled CNTs (SWCNTs) and natural pulp is reported. High‐power shaking realizes the self‐alignment of individual SWCNTs in a cellulose matrix, resulting from the structural change in molecular orientations owing to countless collisions of zirconia beads in the aqueous mixture. The structural analysis of the dried C‐CNT films confirms that the entanglement and dispersion of C‐CNT nanowires determine the mechanical and electrical properties. Moreover, the rheological behavior of C‐CNT inks explains their coating and printing characteristics. By controlling shaking time, the electrical conductivity of the C‐CNT films with only 9 wt.% of SWCNTs from 0.9 to 102.4 S cm−1 are adjusted. the optimized C‐CNT ink is highly compatible with the conventional coating and printing processes on diverse substrates, thus finding potential applications in eco‐friendly, highly flexible, and stretchable electrodes is also demonstrated.