Chemical Bond Formation between Vertically Aligned Carbon Nanotubes and Metal Substrates at Low Temperatures

Chaminda P Nawarathne,Chethani K Ruhunage,Noe T Alvarez,Abdul Hoque,Connor E Rahm

doi:10.3390/app11209529

Chaminda P Nawarathne, Chethani K Ruhunage + Show 3 more

Open Access

https://doi.org/10.3390/app11209529

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Journal: Applied sciences	Publication Date: Oct 14, 2021
Citations: 5	License type: CC BY 4.0

Affiliation: University of Cincinnati

Abstract

The exceptional physical properties of carbon nanotubes (CNTs) have the potential to transform materials science and various industrial applications. However, to exploit their unique properties in carbon-based electronics, CNTs regularly need to be chemically interfaced with metals. Although CNTs can be directly synthesized on metal substrates, this process typically requires temperatures above 350 °C, which is not compatible for many applications. Additionally, the CNTs employed here were highly densified, making them suitable as interconnecting materials for electronic applications. This paper reports a method for the chemical bonding of vertically aligned CNTs onto metal substrates that avoids the need for high temperatures and can be performed at temperatures as low as 80 °C. Open-ended CNTs were directly bonded onto Cu and Pt substrates that had been functionalized using diazonium radical reactive species, thus allowing bond formation with the open-ended CNTs. Careful control during grafting of the organic species onto the metal substrates resulted in functional group uniformity, as demonstrated by FT-IR analysis. Scanning electron microscopy images confirmed the formation of direct connections between the vertically aligned CNTs and the metal substrates. Furthermore, electrochemical characterization and application as a sensor revealed the nature of the bonding between the CNTs and the metal substrates.

Highlights

Carbon nanotubes (CNTs) are macromolecules whose discovery, arguably attributable to Professor Sumio Iijima [1,2], has provided heretofore unimagined potential for engineering applications
This paper reports a method for chemically joining open-ended CNTs to metal substrates (Cu or Pt)
Microtomed high-density CNTs (HD-CNTs) from the same fiber were functionalized at their open ends

Summary

Introduction

Carbon nanotubes (CNTs) are macromolecules whose discovery, arguably attributable to Professor Sumio Iijima [1,2], has provided heretofore unimagined potential for engineering applications. CNTs have garnered immense research interest because of their unique structure and physical properties [3,4,5]. Single-walled CNTs have been shown to have a Young’s modulus of greater than 1 TPa [9], with an electrical resistivity as low as 3 × 10−7 Ω m [10] and a thermal conductivity as high as 3000 Wm K−1 [11,12]. Several researchers have attempted to prepare CNT/Cu composites with varying degrees of success [15,16,17], but in order to take advantage of CNTs’ physical properties, significant efforts have been devoted to growing CNTs on metal substrates in order to achieve chemical bonding [18,19,20]

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