Fabrication of CNT/Cu Composite Yarn via Single-Step Electrodeposition

Abstract

Carbon nanotube (CNT)/Cu composite yarns were formed via a single-step electrodeposition process. A twisted CNT yarn composed of multiwalled CNTs (MWCNTs) was used. Copper was directly electrodeposited onto the CNT yarn under galvanostatic conditions using copper sulfate baths with and without additives. Four additives (polyethylene glycol (PEG), chloride anion (Cl−), bis(3-sulfopropyl)disulfide (SPS), and Janus green B (JGB)) that are well known as “via-filling additives” were used together. The surface and cross-sectional microstructures of the copper-deposited CNT yarns were analyzed. Copper was electrodeposited only onto the surface of the CNT yarn from the bath without additives, resulting in a copper-coated CNT yarn. By contrast, copper was deposited not only onto the surface but also into the interior of the CNT yarn from the bath with the additives. The amount of copper deposited into the CNT yarn tended to increase with increasing PEG and Cl− concentrations. The current density also affected the size and location of the deposited copper particles. When the electrodeposition conditions were optimized, copper was relatively homogeneously deposited into the interior of the CNT yarn, resulting in a CNT/Cu composite yarn.