Mechanically interlocked derivatives of carbon nanotubes: synthesis and potential applications

Single-walled carbon nanotubes (SWNTs) present one of the most interesting collections of properties among nanomaterials. Some sort of chemical modification of SWNTs is often used as a strategy to make the most of their intrinsic properties. In the last few years, the mechanical bond has been added to the chemistry toolbox for SWNT modification. In this Tutorial Review, we first discuss the characteristics of the mechanical bond that make it appealing for materials science in general and SWNTs in particular. We then describe the potential advantages of making mechanically-interlocked derivatives of SWNTs (MINTs), as compared to covalent or classic supramolecular derivatives of SWNTs. We go on to explain the different methods of synthesis of MINTs, highlighting their common features as an indication towards possible future synthetic strategies. Finally, we illustrate with examples how the making of MINTs can contribute to modifying the surface properties of SWNTs, modulating their electronic properties, and linking them to functional molecular fragments. The overall objective of this Review is to introduce the reader to the application of the chemistry of the mechanical bond to SWNTs: why it is relevant, how it is done in practice, what it has shown already as potential contributions towards applications, and what could be done in the future.