Wide-Range Tunable Dynamic Property of Carbon Nanotube-Based Fibers

TL;DR

This paper investigates the dynamic damping properties of carbon nanotube fibers, demonstrating how their structure and treatments can be tuned to achieve a wide range of energy dissipation characteristics for advanced material applications.

Contribution

It reveals how assembly structure and densification methods influence CNT fiber damping, enabling tunable dynamic properties comparable to traditional fibers.

Findings

Entangled CNT fibers have higher loss tangents than aligned CNT fibers.

Liquid densification and polymer infiltration reduce damping by increasing packing density.

Multi-ply CNT yarns can have their damping properties widely tuned.

Abstract

Carbon nanotube (CNT) fiber is formed by assembling millions of individual tubes. The assembly feature provides the fiber with rich interface structures and thus various ways of energy dissipation, as reflected by the non-zero loss tangent (>0.028--0.045) at low vibration frequencies. A fiber containing entangled CNTs possesses higher loss tangents than a fiber spun from aligned CNTs. Liquid densification and polymer infiltration, the two common ways to increase the interfacial friction and thus the fiber's tensile strength and modulus, are found to efficiently reduce the damping coefficient. This is because the sliding tendency between CNT bundles can also be well suppressed by the high packing density and the formation of covalent polymer cross-links within the fiber. The CNT/bismaleimide composite fiber exhibited the smallest loss tangent, nearly as the same as that of carbon fibers. At a higher level of the assembly structure, namely a multi-ply CNT yarn, the inter-fiber friction and sliding tendency obviously influence the yarn's damping performance, and the loss tangent can be tuned within a wide range, as similar to carbon fibers, nylon yarns, or cotton yarns. The wide-range tunable dynamic properties allow new applications ranging from high quality factor materials to dissipative systems.