Vibration Damping of Carbon Nanotube Assembly Materials

Abstract

Vibration reduction is of great importance in various engineering applications, and a material that exhibits good vibration damping along with high strength and modulus has become more and more vital. Owing to the superior mechanical property of carbon nanotube (CNT), new types of vibration damping material can be developed. This paper presents recent advancements, including our progresses, in the development of highdamping macroscopic CNT assembly materials, such as forests, gels, films, and fibers. In these assemblies, structural deformation of CNTs, zipping and unzipping at CNT connection nodes, strengthening and welding of the nodes, and sliding between CNTs or CNT bundles are playing important roles in determining the viscoelasticity, and elasticity as well. Towards the damping enhancement, strategies for micro-structure and interface design are also discussed.

Understanding the Mechanical and Conductive Properties of Carbon Nanotube Fibers for Smart Electronics

“…In the first period, three fiber spinning methods were developed, which are solution spinning, spinning from a presynthesized vertically aligned CNT forest, and direct spinning from an entangled CNT aerogel while being formed in a high‐temperature reactor . In the following several years, the attention was turned to the mechanisms behind the coagulation process in solution spinning to achieve high electrical performance, structure control and continuous production of aerogel‐spun fibers, and forest‐spun fibers with improved strength and electrical conductivity, as well as advanced dynamic mechanical properties . Meanwhile, potential applications of CNT fibers have been developed, including wearable energy storage and harvesting devices, lightweight wires, and actuators .…”

“…The two reference lines represent E ″ = E ′ tan δ = 0.6 and 20 GPa, respectively. Reproduced with permission . Copyright 2018, Wiley‐VCH.…”

“…Therefore, by modifying the intertube properties, a wide‐range tunable dynamic property of CNT‐spun fiber and film materials can be designed and fabricated . The strategies include the densification, infiltration of viscous polymers, introduction of CNT entanglement, multiplying, and so forth, all are strongly related to the strengthening methods as described above.…”

“…Therefore, by modifying the intertube properties, a wide‐range tunable dynamic property of CNT‐spun fiber and film materials can be designed and fabricated . The strategies include the densification, infiltration of viscous polymers, introduction of CNT entanglement, multiplying, and so forth, all are strongly related to the strengthening methods as described above. Considering the high stiffness of CNT fiber, film, and composites, bifunctional mechanical materials can be developed, that is, a high loss tangent can be realized at a high storage modulus (Figure c) .…”

“…The strategies include the densification, infiltration of viscous polymers, introduction of CNT entanglement, multiplying, and so forth, all are strongly related to the strengthening methods as described above. Considering the high stiffness of CNT fiber, film, and composites, bifunctional mechanical materials can be developed, that is, a high loss tangent can be realized at a high storage modulus (Figure c) . For most materials, E ″ = E ′tan δ is less than 0.6 GPa, while for CNT assemblies, the upper limit of E ′ tan δ could be about 20 GPa.…”