Fabrication of copper/carbon nanotube composite thin films by periodic pulse reverse electroplating using nanodiamond as a dispersing agent

• Nano-diamond particles prevent aggregation of carbon nanotubes (CNTs) in electrodeposition.
• Direct current electrodeposition yields high deposition rates.
• Reverse pulse electrodeposition provides higher CNT percentage in copper/CNT composites.

A method for forming a carbon nanotube (CNT) reinforced copper (Cu) composite by an electrodeposition process has been developed. Nanoscale diamond particles were introduced as a dispersing agent to prevent aggregation of carbon nanotubes while performing electrodeposition, or what is commonly referred to as electroplating. The technique involves co-deposition of Cu and CNTs in an electroplating process that uses both direct current and a sequence of forward and reverse pulses. Reverse pulse times were varied in order to examine parameters for dispersion of carbon nanotubes in the resultant composite material. Electrical resistivity, surface morphology, and composite structure were investigated using a probe station, scanning electron microscopy, and x-ray diffraction, respectively. Experimental results show carbon nanotubes can be dispersed uniformly in a Cu/CNT composite due to the role played by the nanodiamond particles in CNT de-aggregation. Direct current electrodeposition yields high deposition rates while reverse pulse electrodeposition is a slower process although necessary for providing a higher percentage of CNTs integrated into the composite.