| 초록 |
Carbon nanotubes (CNTs) have raised considerable interests globally since their first reports in 1991 [1], due to their superior physical properties and unique nanostructure. The prominent performances of CNTs bombarded with papers (~120,000) was enough to expect that they would be novel essential materials in diverse fields including electronics, energy as well as composite materials. However, their applications are still limited although there have been numerous studies for last two decades. In this talk, I will reinterpret the structure of CNTs based on my last 10 years study including high-resolution transmission electron microscope (HRTEM), energy calculation [2,3], simulations of Raman and electronic properties as well as Raman measurements [4]. I will share evidence of a graphene helix [3,4] and an AA’ stacked graphite helix structure [2,5] for single-wall and multi-wall CNTs respectively, which may explain the reasons of the delay or failure of their applications. I will discuss some misinterpretation for commercial SWNTs, their underestimated diameters of 0.8~1.5 nm (generally measured to be ~2 nm by HRTEM observation) and measured semiconducting features (intrinsically metallic). I will also discuss ways of utilizing the one dimensional materials and their potential applications. References 1. Iijima, S., Helical microtubules of graphitic carbon, Nature 354, 56 (1991). 2. J.-K. Lee et al., Structure of multi-wall carbon nanotubes: AA’ graphene helices, Appl. Phys. Lett. 102, 161911 (2013). 3. J.-K. Lee et al., Structure of single-wall carbon nanotubes: A graphene helices, Small 10, 3283 (2014). 4. Park et al., Reinterpretation of single-wall carbon nanotubes by Raman spectroscopy, J. Phys. Chem. C. DOI: 10.1021/acs.jpcc.9b02174 (2019). 5. J.-K. Lee et al., The nature of metastable AA’ graphite: Low dimensional nano- and single-crystalline Forms. Sci. Rep. 6, 39624 (2017). |
