Glycine interaction with carbon nanotubes: an ab initio study

Area of Science:

• Computational Chemistry
• Materials Science
• Nanotechnology

Background:

• Single-walled carbon nanotubes (SWCNTs) are versatile nanomaterials with unique electronic and mechanical properties.
• Understanding molecular interactions on SWCNT surfaces is crucial for designing novel functionalized materials.
• Glycine radicals are reactive intermediates with potential applications in various chemical processes.

Purpose of the Study:

• To investigate the interaction of glycine radicals with armchair and zigzag single-walled carbon nanotubes.
• To determine the binding energies and stability of these interactions using theoretical methods.
• To compare the behavior of N-centered versus C-centered glycine radicals on SWCNT surfaces.

Main Methods:

• Density Functional Theory (DFT) calculations were employed to model the interactions.
• Potential energy surfaces were analyzed to identify stable adsorption configurations.
• Binding energies were calculated to quantify the strength of the interactions.

Main Results:

• The N-centered glycine radical forms stable complexes with both armchair and zigzag SWCNTs.
• Binding energies for the N-centered radical were found to be 16.9 kcal/mol (armchair) and 20.2 kcal/mol (zigzag).
• The C-centered glycine radical, despite being energetically more favorable in isolation, does not form stable complexes with either nanotube type.

Conclusions:

• The N-centered glycine radical exhibits favorable interactions with SWCNTs, suggesting potential for functionalization.
• The C-centered glycine radical's lack of stable complex formation indicates specific orientation or electronic requirements for interaction.
• These findings provide insights into the surface chemistry of carbon nanotubes with amino acid radicals.