Canonical Monte Carlo simulation of adsorption of O2 and N2 mixture on single walled carbon nanotube at different temperatures and pressures

Adsorption of pure and mixtures of O2 and N2 on isolated single-walled carbon nanotube (SWCNT) have been investigated at the subcritical (77 K) and different supercritical (273, 293, and 313K) temperatures for the pressure range between 1 and 31 MPa using (N,V,T) Monte Carlo simulation. Both O2 and N2 gravimetric storage capacity exhibit similar behaviors, gas adsorption is higher on outer surface of tube, compared to the inner surface. Results are consistent with the experimental adsorption measurements. All adsorption isotherms for pure and mixture of O2 and N2 are characterized by type I (Langmuir shape), indicating enhanced solid-fluid interactions. Comparative studies reveal that, under identical conditions, O2 adsorption is higher than N2 adsorption, due to the adsorbate structure. Excess amount of O2 and N2 adsorption reach to a maximum at each temperature and specified pressure which can be suggested an optimum pressure for O2 and N2 storage. In addition, adsorptions of O2 and N2 mixtures have been investigated in two different compositions: (i) an equimolar gas mixture and (ii) air composition. Also, selectivity of nanotube to adsorption of O2 and N2 gases has been calculated for air composition at ambient condition. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010

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Original source : http://dx.doi.org/10.1002%2Fjcc.21428...