Carbon-nanotube-templated carbon nanofibers with improved mechanical performance

The carbon nanotube (CNT) is a compelling and promising material for industrial applications requiring high strength and rigidity. For a multi-walled CNT (MWCNT), the nominal tensile strength and Young's modulus (considering the whole cross-sectional area of the specimen) are key mechanical factors for the practical application of macroscopic fibers and composites. However, the nominal tensile strength and Young's modulus of MWCNTs are much lower than their effective tensile strength and Young's modulus (considering the fracture cross-sectional area) because the outermost graphite layer always fractures first due to the low cross-link between graphite layers. In this paper, we fabricated the carbon nanofibers (CNFs) by epitaxial growth on super-aligned MWCNT film template and conducted in situ uniaxial tensile tests on individual carbon-nanotube-templated CNFs. The individual CNFs show improved nominal mechanical performance than previously reported MWCNTs. The nominal mechanical properties enhancement of the CNFs is attributed to the effective control on load transfer between interwalls.