  The ultra-low intershell shear strength in carbon nanotubes (CNTs) has been
the primary obstacle to applications of CNTs as mechanical reinforcements. In
this paper we propose a new CNT-system composed of comprising of coaxial
cylindrical shells of sp2-bonded carbons with condensed intershell spacings.
Our atomistic calculations show that such condensed multiwalled carbon
nanotubes (CMWNTs) can greatly enhance intershell shear strengths by several
orders, and can simultaneously generate higher tensile strengths and moduli
respectively than those of ordinary CNTs. It has further shown that CMWNTs can
maintain thermally stable up to 2,000 K. By taking advantage of the primary
enhancement mechanism of CMWNTs, a method of producing CMWNTs is therefore
proposed tentatively. It is believed that CMWNTs featured with those properties
can be taken as excellent candidates of super fibers for creating space
elevators.
