The growth of single wall carbon nanotubes (SWCNT) inside host SWCNTs remains a compelling alternative to the conventional catalyst induced growth processes. It not only provides a catalyst free process but the ability to control the constituents of the inner tube if appropriate starting molecules are used. We report herein the growth of inner SWCNTs from $^{13}$C labeled toluene and natural carbon C$_{60}$. The latter molecule is essentially a stopper which acts to retain the smaller toluene. The Raman spectrum of the inner nanotubes is anomalous as it contains a highly isotope shifted "tail", which cannot be explained by assuming a homogeneous distribution of the isotopes. {\color{black}Semi-empirical} calculations of the Raman modes indicate that this unsual effect is explicable if small clusters of $^{13}$C are assumed. This indicates the absence of carbon diffusion during the inner tube growth. When combined with appropriate molecular recognition, this may enable a molecular engineering of the atomic and isotope composition of the inner tubes.
Quantum-mechanical treatment of $^{1}$H$^{+}$ / $^{2}$H$^{+}$ / $^{3}$H$^{+}$ ion dynamics in carbon nanotubes
研究了$^{1}$ H $^{+}$ / $^{2}$ H $^{+}$ / $^{3}$ H $^{+}$离子穿过碳纳米管（CNT）时的量子动力学性质。调查的重点是基于Fortran的程序模拟氢离子通过碳纳米管。我们的工作包括测试模拟的收敛性，理解氢同位素的动力学行为，并研究应用H $^{+}$ + CNT势能曲线。
Water confinement inside a carbon nanotube (CNT) has been one of the most exciting subjects of both experimental and theoretical interest. Most of the previous studies, however, considered CNT structures with simple cylindrical shapes. In this paper, we report a classical molecular dynamics study of the equilibrium structural arrangement of water molecules confined in a multiply connected carbon nanotube (MCCNT) containing two Y-junctions. We investigate the structural arrangement of the water molecules in the MCCNT in terms of the density of water molecules and the average number of hydrogen …
When continued device scaling reaches the ultimate limit imposed by atoms, technology based on atomically precise structures is expected to emerge. Device fabrication will then require building blocks with identified atomic arrangements and assembly of the components without contamination. Here we report on a versatile dry transfer technique for deterministic placement of optical-quality carbon nanotubes. Single-crystalline anthracene is used as a medium which readily sublimes by mild heating, leaving behind clean nanotubes and thus enabling bright photoluminescence. We are able to position na…
Nanoporous materials have the potential to be used as \emph{molecular sieves} to separate chemical substances in a mixture via selective adsorption and kinetic sieving. The separation of isotopologues is also possible via the so-called \emph{quantum sieving} effect: the different effective size of isotopologues due to their different ZPE. Here we compare the diffusion rates of Hydrogen and Deuterium in (8,0) Single Walled Carbon Nanotubes obtained through quantum dynamics methods. The diffusion channels obtained present important contributions from resonances connecting the potential wells. Th…
The attachment of well-defined charge transfer agents to the surface of nanomaterials is an efficient strategy to control their charge density and also to tune their optical, electrical, and physicochemical properties. Particularly interesting are charge transfer agents that either donate or withdraw electrons depending on the arrangements of their building units and that promise a non-destructive attachment to delicate nanomaterials like sp$^2$ compounds. In this work, we rationally synthesize molecular moieties with versatile functionalities. A reactive anchor group allows to attach them to …
