Double walled carbon nanotubes (DWCNTs) are considered an ideal model for studying the coupling interactions between different concentric shells in multi-walled CNTs. Due to their intrinsic coaxial structures they are mechanically, thermally, and structurally more stable than single walled CNTs. Geometrically, owing to the buffer-like function of the outer tubes in DWCNTs, the inner tubes exhibit exciting transport and optical properties that lend them promise in the fabrication of field-effect transistors, stable field emitters, and lithium ion batteries. In addition, by utilizing the outer tube chemistry, DWCNTs can be useful for anchoring semiconducting quantum dots and also as effective multifunctional fillers in producing tough, conductive transparent polymer films. The inner tubes meanwhile preserve their excitonic transitions. This article reviews the synthesis of DWCNTs, their electronic structure, transport, and mechanical properties, and their potential uses.
1. Introduction 2. Synthesis of Catalytically Grown High Purity DWCNTs 3. Fabrication of Thin, Flexible, and Tough DWCNT Buckypaper 4. Raman and X-ray Diffraction Characterizations 5. Thermal Stability of DWCNTs 6. Pore Structure and Oxidative Stability of the Bundled DWCNTs 7. Strong and Stable Photoluminescence from the Semiconducting Inner Tubes within Double Walled Carbon Nanotubes 8. Outer Tube Chemistry 10. Superconducting Behavior of the Bundled DWCNTs 11. Promising Applications of DWCNTs 12. Conclusions Acknowledgements References
