Filling carbon nanotubes with argon

The specific surface area of multi-walled carbon nanotubes (MWCNT) of different geometry and structures is measured by the method BET. The nanotubes were synthesized by the use of highly effective Fe–Co catalysts through the method of polymerized complex precursors. In some cases, the measured specific surface area considerably exceeds that calculated under the assumption that the Ar adsorption occurs on the outer surface of CNTs. This permits one to conclude that in some cases a part of argon adsorbed fills the internal hollow of nanotubes.