However, CNT yarns prepared commercially in the bulk have only half the tensile strength of conventional high-performance carbon fibers. Theoretical studies show that CNT yarns can exhibit more than ten times the tensile strength of current carbon fibers. There are several methods to grow, align, and fabricate yarns of CNTs. Because of the difficulties in dispersing pristine CNTs in polymers, the assembly of CNTs into macroscopic fibers, with the tubes aligned parallel along the CNT yarn axis, has been focused on. Although many investigations have been carried out with these materials, it still remains a challenge to assemble CNTs in materials on the macroscopic scale.
Keywords: carbon nanotube yarns crosslinking electron beam graftingĭue to their exceptional mechanical, thermal, and electrical properties (Young’s modulus of 1 TPa, tensile strength above 100 GPa), carbon nanotubes (CNTs) are promising materials for various advanced technologies, including CNT-reinforced polymer composites. CNT yarn treatment with AA enhanced the strength (444.5 ± 68.4 MPa) by more than 75% and the modulus (21.5 ± 0.6 GPa) by more than 144% as compared to untreated CNT yarn (strength 251 ± 26.5 MPa and modulus 8.8 ± 1.2 GPa). The best improvement in mechanical properties was achieved on a sample treated with an aqueous solution of AA and subsequent irradiation. The chemical modification of CNT yarns was confirmed by X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and scanning electron microscopy (SEM). To this end, CNT yarns were simultaneously functionalized and crosslinked using acrylic acid (AA) and acrylonitrile (AN) in an e-beam irradiation process. Electron beam (e-beam) irradiation was employed for in a single-step surface modification of CNTs to improve the mechanical properties of this material. Carbon nanotube (CNT) yarns exhibit low tensile strength compared to conventional high-performance carbon fibers due to the facile sliding of CNTs past one another.