Copper-CNT interfacing with Cu-doped polydopamine in CNT carpet: copper nucleation and resistance decrease upon soft...

Area of Science:

• Materials Science
• Nanotechnology
• Composite Materials

Background:

• Copper-carbon nanotube (Cu-CNT) composites offer superior properties compared to pure copper, including higher ampacity and lower thermal resistance.
• Fabricating efficient Cu-CNT composites is challenging due to the inherent cuprophobicity of carbon nanotubes (CNTs).

Purpose of the Study:

• To enhance chemical interactions between copper (Cu) and CNTs by employing a Cu-doped polydopamine (PDA) coating as an interfacial layer.
• To investigate the nucleation and growth of copper particles on PDA-coated multi-walled carbon nanotubes (MWCNTs) after annealing.

Main Methods:

• Coating MWCNTs with Cu-doped PDA.
• Annealing the coated MWCNTs in an inert atmosphere at temperatures of 573 K, 673 K, and 773 K.
• Characterizing the resulting Cu-CNT composites, including sheet resistance measurements and analysis of copper particle morphology.

Main Results:

• The PDA coating effectively reduces Cu ions to metallic copper during annealing.
• Sheet resistance of CNT carpets decreased by up to 37.6% after annealing at 773 K.
• The reduction in sheet resistance is attributed to the formation of pyridinic nitrogen in the PDA structure at temperatures of 673 K and above.
• All fabricated Cu-CNT carpets exhibited a negative temperature coefficient of resistance.

Conclusions:

• Cu-doped PDA serves as an effective interfacial layer for fabricating high-performance Cu-CNT composites.
• Annealing promotes copper nucleation and significantly improves the electrical conductivity of CNT carpets.
• The observed properties suggest potential applications in advanced electronics and thermal management systems.