Mechanical Strength Improvements of Carbon Nanotube Threads through Epoxy Cross-Linking

Abstract

Individual Carbon Nanotubes (CNTs) have a great mechanical strength that needs to be transferred into macroscopic fiber assemblies. One approach to improve the mechanical strength of the CNT assemblies is by creating covalent bonding among their individual CNT building blocks. Chemical cross-linking of multiwall CNTs (MWCNTs) within the fiber has significantly improved the strength of MWCNT thread. Results reported in this work show that the cross-linked thread had a tensile strength six times greater than the strength of its control counterpart, a pristine MWCNT thread (1192 MPa and 194 MPa, respectively). Additionally, electrical conductivity changes were observed, revealing 2123.40 S·cm−1 for cross-linked thread, and 3984.26 S·cm−1 for pristine CNT thread. Characterization suggests that the obtained high tensile strength is due to the cross-linking reaction of amine groups from ethylenediamine plasma-functionalized CNT with the epoxy groups of the cross-linking agent, 4,4-methylenebis(N,N-diglycidylaniline).

Fabrication and study of supercapacitor electrodes based on oxygen plasma functionalized carbon nanotube fibers

“…Since the plasma flux attenuates when penetrating the fiber, its core remains unchanged. This is in agreement with previous work from our group [66] which proved that the plasma functionalization decayed radially in cylindrical objects such as our fibers with diameters greater than 10 μm. For our fibers with approximate diameters of 55 μm, the effect of the plasma was most pronounced in the outer layer of the fibers and not in its core.…”

Grafting of the carbon allotropes and polypyrrole via a Kevlar-type organic linker: the correlation of carbon structure/morphology with electrochemistry of the composite electrode

“…Figure 5 represents the TGA curves for all composites in the range from 25 to 650°C. According to literature, grafted carbons decompose in this temperature regime (excluding water loss) starting from the detachment of the carbon-amide linker, followed by the degradation of polymer-linker, and the degradation of polypyrrole at higher temperatures [56,57]. The corresponding transitions are projected in Fig.…”

A review of recent research on materials used in polymer–matrix composites for body armor application

“…A very effective method for this is plasma functionalization, this technique modifies the surface morphology of CNTs by introducing some defects and functional groups, hence improves their dispersion and their agglomerations breaking-up. 20…”