NEXAFS study of multi-walled carbon nanotubes functionalization with sulfonated poly(ether ether ketone) chains

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Multi-walled carbon nanotubes (MWNTs) possess unique properties but require surface functionalization for improved compatibility and performance in composite materials.
• Sulfonated poly (ether ether ketone) (SPEEK) is a high-performance polymer with desirable chemical and thermal properties.

Purpose of the Study:

• To investigate the direct attachment reaction for functionalizing MWNT surfaces with SPEEK chains.
• To develop a method for covalently linking SPEEK to MWNTs to create novel hybrid materials.

Main Methods:

• A two-step functionalization process involving nitric acid oxidation of MWNTs to introduce carboxyl groups.
• Grafting of SPEEK onto oxidized MWNTs using hexane diamine as an interlinking molecule.
• Characterization using Transmission Electron Microscopy (TEM), Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy, and X-ray Photoelectron Spectroscopy (XPS).

Main Results:

• TEM confirmed the successful wrapping of MWNTs by SPEEK polymer chains.
• NEXAFS and XPS provided evidence of covalent bonding between the SPEEK macromolecules and the MWNT surfaces.
• The direct attachment reaction effectively functionalized the MWNTs with SPEEK.

Conclusions:

• The study successfully demonstrated a covalent functionalization method for MWNTs using SPEEK.
• The resulting SPEEK-functionalized MWNTs show potential for applications requiring enhanced interfacial adhesion and tailored properties.
• This approach offers a pathway for developing advanced nanocomposite materials with improved performance.