Interaction of Gases on Single-Wall Carbon Nanotubes
Abstract
This project is a continuation of the earlier study on Interaction of water and methanol with single wall carbon nanotubes. The objective of the project was to supplement previous work by considering (1) more than one molecule in the interaction, (2) extending the previous work by examining interactions with bundles of carbon nanotubes rather than a single nanotube, (3) comparing interactions within and between nanotubes, and "4" examining effects of nanotube deformation on the interaction. This study is to support the experimental work done using Raman spectroscopy by Prof. Maher Amar of Wright State University in association with Dr. John F. Maguire of the Air Force Research Laboratory.In general the interaction energies of H2O and CH3OH molecules on a "10,10" SWCNT, C60 and a graphene sheet are quite small "a few tens of meV" and it is weakly dependent on the orientation of the molecules. This is presumably due to the large HOMO-LUMO gap "6.2 and 5.58 eV "GGA" for water and methanol, respectively". The electronic structures "gap" of graphene, nanotubes and C60 differ and this could contribute to the differences. For "10,10" nanotube the interaction energy is more favorable outside "39 meV" the nanotube for water. This energy is significantly lower than the cohesive energy of water and therefore water is suggested to wet the nanotube because two molecules outside a nanotube form a dimer. The interaction energy for a dimer "see table below" also increases as compared to a single molecule. On the other hand for methanol the interaction energy for the two cases, outside as well as inside, is nearly the same, though the value remains small "40 meV". It is predicted that the competition between the molecules and molecule-nanotube wall could lead to interesting ordering in the nanotube which could depend on the size of the nanotube.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 18, 2006
- Accession Number
- ADA473070
Entities
People
- Vijay Kumar