(Digital Presentation) Modification of Physicochemical Properties of Carbon Nanotubes By Chemical Functionalization

Abstract

Carbon nanotubes (CNTs) are still one of the most promising nanocarbon materials despite being researched for over 30 years so far. CNTs have magnificent physical and chemical properties such as appreciable tensile strength, high electrical and thermal conductivity, tunable surface character, and chemical activity. However, the amount of structural defects can strongly impact these properties. Nevertheless, from a chemical point of view, these structural damages are often necessary to integrate CNTs with different materials. One of the most popular functionalization strategies is oxidization, which increases the hydrophilicity of the material at the expense of electrical conductivity.In our research we focused on analysis, how different reduction parameters influence changes in properties of the material. We used modified Hummers method was used to oxidize single-walled carbon nanotubes (SWCNTs) and later reduction was conducted with use of hydrogen in elevated temperature in tube furnace. The process was monitored with Raman spectroscopy, Scanning Electron Microscopy and X-ray photoelectron spectroscopy to track ongoing changes. All materials, obtained in successful synthesis, were characterized to determinate the following properties: water contact angle (WCA), electrical and thermal conductivity and Seebeck coefficient. It was observed that due to reduction Seebeck coefficient increased from 24 μV/K for oxidized material to 39 μV/K after reduction, while WCA changed from 24° to 39°. This method has potential for future modeling of their properties and improved modification process can lead to new field of applications in thermoelectric of carbon nanomaterials.