Multiwalled carbon nanotubes coated with twin-strengthened copper

Abstract

This work reports a facile method to fabricate copper-coated CNTs containing lamellar twins that deliver improved mechanical properties. The coating process is carried out via a wet chemical reduction method with molecular level mixing technique. Detailed optimization experiments reveal the effect of the reduction speed of the precursor on the morphology of the copper-based nanostructures and their efficacy in achieving uniform coating on the CNTs. The origin of the different nanostructures is studied via crystallographic simulation and supported by the LaMer mechanism. The prepared nanocomposites exhibit improved mechanical properties compared to pure Cu as well as other Cu-CNT based materials reported in the literature. The dependence of mechanical properties on the particle morphology of the precursor nanostructures is also examined. This improvement is due to the strong interfacial bonding between Cu and CNTs and the presence of lamellar twins in Cu, as observed from TEM analysis. The measured elastic modulus values of the nanocomposites are in good agreement with the values predicted by Halpin-Tsai and Shear-lag models.