Scheme: University Research Fellowship
Organisation: University of Nottingham
Dates: Oct 2010-Sep 2013
Summary: For over 600 years scientists have been using laboratory glassware (test tubes, retorts, flasks, beakers) to discover and test the properties of chemical elements. Recently we have demonstrated that carbon nanotubes – cylinders of carbon 10,000,000 times thinner than laboratory test tubes and possessing zeptolitre volumes, can accommodate tiny samples of 50-60 atoms of individual elements. The high chemical and thermal stabilities of nanotubes make them ideal nanoscale containers for a wide range of elements which can be studied at the level of individual atoms using high-resolution transmission electron microscopy (HRTEM). The structure and dynamic behaviour of the elements from different groups and periods of the Periodic Table confined inside SWNT reveal chemical traits that only become apparent when examined at the nanoscale.
Confinement of a series of metals in nanoscale test tubes provides a new way to study the properties of the chemical elements. A rich tapestry of different dynamic and chemical behaviours of nanometre sized clusters of transition metals is observed in carbon nanotubes and offers the possibility to study the mechanisms of chemical reactions in direct space at the atomic level by means of HRTEM. This technique can be utilised to complement or in the long term even replace conventional spectroscopy methods which study reactions of large number of atoms or molecules (c.a. 10,000,000,000,000,000) and therefore only observe chemical properties averaged over a large ensemble of species. As an understanding of the properties of individual atoms is becoming increasingly more important for the development of nanoelectronics, nanocatalysis, nanomedicine and other areas of nanotechnology, measurements and interpretation of chemistry happening at the atomic level is opening up a new chapter of the chemistry of the elements.
Dates: Oct 2005-Sep 2010
Summary: All living creatures are based on carbon. The diversity of life shows the great structural versatility of carbon as a chemical element. In my research I utilise carbon as a construction material for nano-sized vesicles (fullerenes) and tubes (nanotubes). Despite their ultra-small size (nanotube, for example, is 80,000 times thinner than a human hair), these carbon nanostructures are very strong mechanically and possess a whole range of useful physical properties.
I utilise the internal void of nanotubes and fullerenes to store atoms and molecules. For example, erbium (Er) atoms that can interact with light and are already used for telecommunications have been incarcerated within the carbon cages of fullerenes (forming so-called “endohedral fullerenes”). The exterior of the carbon cages was modified to make them stick onto metallic surfaces. This technique allowed us to assemble very large 2D arrays of these fullerenes, each bearing three Er atoms inside. This opens new avenues for incorporation of these unique optically active molecules into nano-electronic functional devices.
Carbon nanotubes are used as extremely small test tubes in my research. In the past I showed that we can put many different types of molecules into nanotubes that can line up along the nanotube axis and form interesting structures that do not exist outside nanotubes. Recently, using state of the art electron microscopy I demonstrated that we can initiate and to watch a chemical reaction inside nanotube in real time at the atomic scale! For the first time we were able to watch individual atoms within the molecules colliding with each other and forming new molecules (you may like to watch the movie on www.nottingham.ac.uk/nanocarbon/TEM ). Nanotubes have been utilised as ultra-small chemical reactors fulfilling a dream of many chemists to monitor atoms in real space as they react with each other.