(3cr) Transport of Molecules and Ions Along the Exterior of Individual Carbon Nanotubes

Carbon nanotubes (CNTs) have a one-dimensional (1D) tubular structure with both the interior and exterior available for the transport of ions and various molecular species. Recent studies have largely focused on interior transport through nanotubes, whereas the exterior transport has been largely overlooked. The exterior channel of CNTs is unique for investigating the transport phenomenon at the nanoscale owing to their π-electron-rich surfaces, atomically smooth surfaces, entire surface chemistry, and greater compatibility with ambient conditions than the interior channel. My research demonstrates the first experimental evidence of preferential migration of cations along the exterior of CNTs. The smooth and π-electron-rich surface of CNTs enables the transport of charged species over a milliliter length at the orders of magnitude lower than that of an electric field in other relevant systems. The cation-preferring 1D nanochannels have broad implications for charge-specific chemistry, single molecular transport and detection, and energy storage devices. The hygroscopic micro/nanolenses of various alkali metal halides were reported to be arranged as parallel 1D arrays using the ion channels of CNTs as a template for forming the salt lenses. These lenses are promising for use in the optical visualization and spectroscopy of underlying nanomaterials and for detecting trace amounts of surface-bound or soluble molecular species that are not easily detectable using existing approaches. These salt micro/nanolenses, which are robust and nondestructively removable, will have applications in optical or spectroscopic studies in 1D space, including electrokinetic separation of molecules, chemical reactions, and molecular detection in highly saline environments. My research interests include the development of novel carbon nanomaterials such as graphene nanoribbons and carbon nanomaterial intramolecular junctions, and electronic and optoelectronic applications based on carbon nanomaterials.