
Session U25 - Focus Session: Carbon Nanotubes: Gas Adsorption and Transport.
FOCUS session, Thursday afternoon, March 21
205, Indiana Convention Center
We have studied pure ^4He desorption and ^4He - H_2 codesorption from single-walled carbon nanotube bundles. It is observed that the presence of H_2 suppresses ^4He adsorption while H_2 adsorption is not effected by the presence of ^4He. This suggests that the adsorption of Hydrogen occurs primarily on the outer grooves of the nanotube bundles [1], or that the Hydrogen binding energy is higher than Helium in the interstitial sites of the bundles, in agreement with recent theoretical expectations [2]. We expect to report on further experiments on Helium codesorption with other inert atoms as results are available.
[1] G. Stan, M.J. Bojan, S. Curtarolo, S.M. Gatica, and M.W. Cole, Phys. Rev. B 62, 2173 (2000). [2] M.M. Calbi, F. Toigo, and M.W. Cole, Phys. Rev. Lett. 86, 5062 (2001).