The present research line is led by Dr. Gerard Tobias and focuses on the development of carbon and inorganic based functional nanomaterials. Special emphasis is paid to exploit the synergies of both types of materials by tailored preparation of “nanocomposites” with novel or enhanced properties. Current research interests are grouped into the following interlinked topics:
Carbon nanomaterials
Design and applications of filled carbon nanotubes
One of our main research interests is directed towards exploring the applications that the encapsulation of materials inside carbon nanotubes (“carbon nanocapsules”) might have in different areas. Using this approach we have recently shown that radionuclide filled carbon nanotubes allow ultrasensitive imaging and a complete redirected biodistribution of the encapsulated radionuclides. Surface functionalisation of these nanocapsules offers versatility towards modulation of the in vivo fate of the radioemitting crystals in a manner determined by the nanocapsule that delivers them (Nature Materials 2010. 9, 485; see also "News and Views": Nature Materials 2010, 9, 467; Nature Chemisty 2010, 604, 2; Nano Today 2010, 5, 245).
These filled carbon nanotubes also offer great potential as drug delivery systems. In this case a controlled release of the encapsulated payload is desired. To this end we have developed pH-sensitive "nano-corks" that allow a triggered release of the encapsulated compounds by lowering the pH of the aqueous media (Carbon 2010, 48, 1912; Chem. Commun. 2008, 2164).
Chemistry of carbon nanomaterials
Research under the broad heading of "Chemistry of carbon nanomaterials" focuses on different aspects that are essential for the processing and application of these nanomaterials (mainly carbon nanotubes and graphene), ranging from their purification to the formation of composite materials, going through their functionalisation with both organic and inorganic compounds.
We have shown that purification of as-prepared carbon nanotubes can be achieved by using steam as a mild oxidizing agent. The resulting purified samples have a low degree of catalyst contents, amorphous carbon, defects, and functional groups (Small 2008, 4, 1501). The absence of amorphous carbon allows an efficient sidewall covalent functionalisation of CNTs (Chem. Commun. 2007, 5090; Adv. Mater. 2007, 19, 883). In the area of sidewall functionalisation, we have demonstrated that rational design of organic molecules containing heavy element tags (iodide) allows direct detection by electron microscopy techniques in the subnanometer scale (J. Am. Chem. Soc. 2007, 129, 10966) and are currently developing protocols that allow direct sidewall covalent functionalisation whilst minimizing the formation of structural defects (J. Mater. Chem. 2011, 21, 19080).
