A novel high yield method for dry functionalization of carbon nanotubes

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Carbon nanotubes (CNTs) possess unique properties but often require surface modification to enhance their utility.
• Traditional functionalization methods can be complex or inefficient, necessitating the development of improved techniques.

Purpose of the Study:

• To report a novel, high-yield dry functionalization method for multi-walled carbon nanotubes (MWCNTs).
• To investigate the effects of hydrothermal treatment on CNT surface structure and properties.

Main Methods:

• A dry functionalization technique utilizing a hydrothermal method with a specific acid and peroxide mixture (HNO3, H2SO4, H2O2 in 1:3:2 vol. ratio).
• Reactions were conducted at temperatures ranging from 120 to 200°C for 24 hours, with CNTs kept separate from direct solution contact.
• Characterization was performed using Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), and X-ray Photoelectron Spectroscopy (XPS).

Main Results:

• High functionalization yield (>80%) was achieved.
• Optimal functionalization occurred above 180°C, confirmed by FTIR.
• FESEM revealed structural changes including open ends, granular surfaces, and aggregation, indicating graphite structure modification.
• XPS confirmed successful functionalization through shifts in C 1s peaks, increased O 1s intensity, and the appearance of an N 1s peak.

Conclusions:

• The developed hydrothermal dry functionalization method is effective and high-yielding for CNTs.
• The treatment significantly alters CNT surface morphology and chemical composition, increasing reactivity.
• This method offers a promising approach for tailoring CNT properties for advanced applications.