It is shown that nanotubes with thicker walls can be grown from strongly bonded multi-layered structures only in accord with some basic crystallographic principles. Either the diameters of such tubes remain large in comparison with the thicknesses of their walls, or new bulk structures are formed.
@article{arxiv.0901.3455,
title = {Structural Restrictions and Inorganic Nanotubular Growth},
author = {Albert Prodan and Herman J. P. van Midden and Erik Zupanic},
journal= {arXiv preprint arXiv:0901.3455},
year = {2009}
}