Dependence of Single-Walled Carbon Nanotube Adsorption Kinetics on Temperature and Binding Energy

• Published in: Langmuir Vol. 24; no. 23; pp. 13465 - 13469
• Main Authors: Rawat, D. S, Krungleviciute, V, Heroux, L, Bulut, M, Calbi, M. M, Migone, A. D
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 02.12.2008
• Subjects: Adsorption; Binding Sites; Chemistry; Colloidal state and disperse state; Exact sciences and technology; Fluorocarbons - chemistry; General and physical chemistry; Hydrogen - chemistry; Interfaces: Adsorption, Reactions, Films, Forces; Kinetics; Methane - chemistry; Nanotubes, Carbon - chemistry; Surface physical chemistry; Surface Properties; Temperature; Thermodynamics; Time Factors; Methane; Singlewalled nanotube; Adsorption; Computer simulation; Hydrogen; Binding energy; Prediction; Kinetics; Carbon; Equilibrium
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la8022002

We present results for the isothermal adsorption kinetics of methane, hydrogen, and tetrafluoromethane on closed-ended single-walled carbon nanotubes. In these experiments, we monitor the pressure decrease as a function of time as equilibrium is approached, after a dose of gas is added to the cell containing the nanotubes. The measurements were performed at different fractional coverages limited to the first layer. The results indicate that, for a given coverage and temperature, the equilibration time is an increasing function of E/(k B T), where E is the binding energy of the adsorbate and k B T is the thermal energy. These findings are consistent with recent theoretical predictions and computer simulations results that we use to interpret the experimental measurements.