Double walled nanotube

Double-walled carbon nanotubes (DWNTs) form a special class of nanotubes because their morphology and properties are similar to those of SWNTs but their resistance to chemicals is significantly improved. This is especially important when functionalization is required (this means grafting of chemical functions at the surface of the nanotubes) to add new properties to the CNT. In the case of SWNTs, covalent functionalization will break some C=C double bonds, leaving "holes" in the structure on the nanotube and, thus, modifying both its mechanical and electrical properties. In the case of DWNTs, only the outer wall is modified. DWNT synthesis on the gram-scale was first proposed in 2003[8] by the CCVD technique, from the selective reduction of oxide solutions in methane and hydrogen.

  • Energy Flow in the Nano Range

    Energy transport in biomimetic nanotubes (left) and a three-dimensional spectrum (right). Bjoern Kriete (l.) / Stefan Mueller (r.)

    It is crucial for photovoltaics and other technical applications, how efficiently energy spreads in a small volume. With new methods, the path of energy in the nanometer range can now be followed precisely. Plants and bacteria lead the way: They can capture the energy of sunlight with light-harvesting antennas and transfer it to a reaction centre. Transporting energy efficiently and in a targeted fashion in a minimum of space – this is also of interest to mankind. If scientists were to master it perfectly, they could significantly improve photovoltaics and optoelectronics.