DESORPTION BEHAVIOR OF GASEOUS MOLECULES ON SINGLE-WALLED CARBON NANOTUBE BUNDLES
B.Y. Wei1, H.M. Lin1, Y.S. Yang2,
H.J. Lai3 and S.H. Chien1
1 Department of Materials Engineering, Tatung University, 40 ChungShan N. Rd.,
Sec. 3, Taipei 104, Taiwan
2 Institute of Chemistry, Academia Sinica, Taipei 11529, Taiwan
3 Materials Research Laboratories, Industrial Technology Research Institute,
Hsinchu 310, Taiwan
Temperature programmed desorption (TPD) technology was used to examine desorption
activation energies (Ed) of O2, N2 and
Ar on single-walled carbon nanotube (SWCNT) bundles.
The SWCNT bundles obtained from Carbon Nanotechnologies Inc. were prepared by high-pressure
CO (HiPco) disproportionation process, and had diameters of approximately 0.8 nm. The results
show that the temperatures at which the maximum desorption rates of O2, N2 and Ar on SWCNTs
are all below 200 °C, and the corresponding Ed values are 209, 192 and 188 meV, respectively.
The Ed values are very close to the isosteric heat of adsorption (qst) obtained from our
previous studies, implying that these gases are physisorbed onto SWCNTs.
full paper (pdf, 224 Kb)