Quantum Molecular Sieving Effects of H 2 and D 2 on Bundled and Nonbundled Single-Walled Carbon Nanotubes

The quantum molecular sieving effects of pore-structure-controlled single-walled carbon nanotubes (SWCNTs) for H 2 and D 2 were evaluated at 20, 40, and 77 K. The adsorption amounts of D 2 were larger than those of H 2 . The lower the adsorption temperature, the greater the difference between the D 2 and H 2 adsorption amounts. Bundled SWCNTs with interstitial pores of diameter 0.6 nm gave the greatest adsorption difference between D 2 and H 2 per unit pore volume. Diffusion-dominated behavior was observed in the low-pressure region at 20 and 40 K as a result of lower mobility. Bundled SWCNTs with only interstitial pores provided a significant quantum molecular sieving as a result of strongly interacting potential wells.