The importance of carbon nanotube wire density, structural uniformity, and purity for fabricating homogeneous carbon nanotube-copper wire composites by copper electrodeposition

摘要

We present the influence of density, structural regularity, and purity of carbon nanotube wires (CNTWs) used as Cu electrodeposition templates on fabricating homogeneous high-electrical performance CNT-Cu wires lighter than Cu. We show that low-density CNTWs (0.6 g/cm(3) for multiwall nanotube wires) with regular macro-and microstructures and high CNT content (90wt %) are essential for making homogeneous CNT-Cu wires. These homogeneous CNT-Cu wires show a continuous Cu matrix with evenly mixed nanotubes of high volume fractions (similar to 45 vol %) throughout the wire-length. Consequently, the composite wires show densities similar to 5.1 g/cm(3) (33% lower than Cu) and electrical conductivities similar to 6.1 x 10(4) S/cm ( 100 x CNTW conductivity). However, composite wires from templates with higher densities or structural inconsistencies are non-uniform with discontinuous Cu matrices and poor CNT/Cu mixing. These non-uniform CNT-Cu wires show conductivities 2-6 times lower than the homogeneous composite wires. (C) 2018 The Japan Society of Applied Physics.