SPECCNT · Theoretical Study of NMR and Raman Spectra of Functionalized and Intercalated Nanotubes
6РП — Действия „Мария Кюри“
- Период
- 2004-12-01 → 2005-09-30
- Финансиране от ЕС
- 149 670 €
- Участници
- 1
- Схема
- EIF
Линиите свързват координатора с партньорите.
Накратко на български
Въглеродните нанотръби се анализират теоретично чрез спектроскопия, за да се разбере как диаметърът и структурата им влияят на магнитните им свойства. Това помага за по-точното тълкуване на експерименталните данни и насочва бъдещите изследвания върху тези материали.
Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.
Резултати накратко
Final Activity Report Summary - SPECCNT (Theoretical Study of NMR and Raman Spectra of Functionalized and Intercalated Nanotubes)
The discovery of carbon nanotubes (CNT) in the 1990s by Iijima caused a flurry of experimental and theoretical investigations of this fascinating new form of carbon. CNTs are micrometer-long hollow carbon cylinders and can be seen as graphene sheets (honeycomb two-dimensional carbon lattices), rolled-up like a cigarette with nanometer-scale radii. The tubes have extraordinary mechanical and electronic properties, which make them good candidates for nanostructured multifunctional materials. Very often, the characterisation of CNTs is done using spectroscopic tools. However, this characterisation is generally indirect, i.e. the experimental result is compared to several theoretical models in order to find an agreement. In view of this, it is clear that there is an apparent need in the community for a theoretical description of nanotubes, not only to understand available experimental data, but also to guide future experiments. Therefore, this research project was dedicated to the theoretical and numerical characterisation of intercalated, doped and functionalised carbon nanotubes, using both nuclear magnetic resonance (NMR) and Raman spectroscopies. With this project we took an important step in this direction, by providing benchmark calculations for the magnetic susceptibility and NMR chemical shift of carbon nanotubes, both isolated and in bundles. Both properties exhibited dependence on the diameter D and the chirality of the tube, even though this dependence was stronger for the susceptibility. Moreover, we calculated the chemical shift of a double-wall tube and found a diamagnetic shift of the isotropic lines corresponding to the atoms of the inner tube because of the effect of the outer tube. This shift was in good agreement with recent experiments and could be explained by demagnetising currents circulating the outer tube.
Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз
Цел на проекта
There has been considerable interest in derivatization of carbon nanotubes to modify their electronic, chemical, transport, etc. properties. Some examples are: i) functionalization of nanotubes to facilitate their manipulation, enhance their solubility, an d make them more amenable to composite formation; lithium intercalated carbon nanotubes have attracted considerable interest for energy storage devices; the introduction of donor/acceptor levels through substitutional doping of the material to control the electronic properties; etc. However, from a theoretical prespective little is know about functionalized and intercalated nanotubes. This research project is dedicated to the theoretical/numerical characterization of intercalated and functionalized carbon n anotubes by the interpretation of nuclear magnetic resonance (NMR) and Raman spectroscopic data. These two techniques have an extremely high sensitivity to the local environment of a C bond. In particular, we will provide reference NRM and Raman theoretica l spectra, in the search for clear signatures of the microscopic structure of the nanotubes. The signatures can be used to characterize macroscopic samples of tubes. To achieve these objectives, we will use state-of-the-art ab initio computational methods, due to their predictive power and reliability. This work will be done in close connection to experimental groups. In one hand, input from experiment will help assessing and validating the theoretical models. On the other hand the theory may be helpful to drive further experimental studies.This project will contribute to the building-up of basic knowledge in the strategic and highly impact area of nano-technology. In addition, the multidisciplinarity character of the project and its objectives will help to enhance European scientific excellence.
Оригинален текст от CORDIS (на английски).
Участници
- UNIVERSITE PIERRE ET MARIE CURIE · PARISКоординаторФранция
Връзки
Данни: CORDIS, © Европейски съюз