Characterization of Carbon Nanotube Fiber Compressive Properties Using Tensile Recoil Measurement

Abstract

The tensile properties of carbon nanotube (CNT) fibers have been widely studied. However, the knowledge of their compressive properties is still lacking. In this work, the compressive properties of both pure CNT fibers and epoxy infiltrated CNT fibers were studied using the tensile recoil measurement. The compressive strengths were obtained as 416 and 573 MPa for pure CNT fibers and CNT-epoxy composite fibers, respectively. In addition, microscopic analysis of the fiber surface morphologies revealed that the principal recoil compressive failure mode of pure CNT fiber was kinking, while the CNT-epoxy composite fibers exhibited a failure mode in bending with combined tensile and compressive failure morphologies. The effect of resin infiltration on CNT fiber compressive properties, including the compressive strength and the deformation mode, is discussed. This work expands the knowledge base of the overall mechanical properties of CNT fibers, which are essential for their application in multifunctional composites.

A durability study of carbon nanotube fiber based stretchable electronic devices under cyclic deformation

“…This potential was first noticed by Zu et al [14] and Wu et al [15] in the measurement of compressive strength of CNT fibers using a tensile recoil experiment. It turned out that massive buckling took place in the fractured CNT fiber segments.…”

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

“…b) Surface morphologies of a CNT fiber after recoil test at tensile failure stress of 1.48 GPa. Reproduced with permission . Copyright 2012, American Chemical Society.…”

“…For CNT fibers, there have been plenty of studies on the tensile properties for CNT fibers. For the compressive properties, Zu et al designed the single‐fiber tensile recoil test: after a static tensile load is applied, the fiber recoil is initiated by cutting the fiber at the midpoint of the gauge length using ultrafine clipper scissors. Under the assumption of no energy dissipation, the magnitude of the compressive stress wave generated during a specimen recoil is equal in magnitude but of opposite sign to the initial tensile stress.…”

Superstructured Assembly of Nanocarbons: Fullerenes, Nanotubes, and Graphene

“…As suggested by the microscopic analysis of the fiber surface morphologies, kinking was the primary compressive failure mode for pure CNT fibers, while composite fibers with higher brittleness showed the bending failure mode (Figure 11a,b). 217 Later, the same group delivered a successive study on the stress relaxation behavior of the two CNT-based fibers, where stress decay was observed in both pure and CNT/epoxy composite fibers when they were held under constant strain (Figure 11c). The timedependent relaxation behavior in CNT fibers, yet not evidently seen in carbon fibers, was supposed to originate from the sliding between CNT bundles and affected by the initial strain level, strain rate, and gauge length.…”