Adsorption and capillarity of nitrogen in aggregated multi-walled carbon nanotubes

Pores in aggregated multi-walled carbon nanotubes (MWNTs) can be mainly div ided into inner hollow cavities of smaller diameter (narrowly distributed, mainly 3.0-4.0 nm) and aggregated pores (widely distributed, 20-40 nn), for med by the interaction of isolated MWNTs. The two types of pores shall, res pectively, determine nitrogen cryogenic capillarity process under different pressures. It is worth to note that ultra-strong nitrogen capillarity in t he aggregated pores (590 mg N-2/g) contributes to the 78.5% of the total ad sorption amount (up to 750 mg/g near to the ambient pressure), showing that the aggregated pores of the MWNTs are much more important than their inner cavities for adsorption and capillarity in some cases. (C) 2001 Elsevier S cience B.V. All rights reserved.