Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CC 16, Sucursal 4 (1900) La Plata, Argentina.
Langmuir. 2012 Jan 24;28(3):1824-32. doi: 10.1021/la204314a. Epub 2012 Jan 9.
We present the results of Monte Carlo simulations of the adsorption of single-component ethane and ethylene and of equimolar mixtures of these two gases on bundles of closed, single-walled carbon nanotubes. Two types of nanotube bundles were used in the simulations: homogeneous (i.e., those in which all the nanotubes have identical diameters) and heterogeneous (those in which nanotubes of different diameters are allowed). We found that at the same pressure and temperature more ethane than ethylene adsorbs on the bundles over the entire range of pressures and temperatures explored. The simulation results for the equimolar mixtures show that the pressure at which maximum separation is attained is a very sensitive function of the diameter of the nanotubes present in the bundles. Simulations using heterogeneous bundles yield better agreement with single-component experimental data for isotherms and isosteric heats than those obtained from simulations using homogeneous bundles. Possible applications of nanotubes in gas separation are discussed. We explored the effect of the diameter of the nanotubes on the separation ability of these sorbents, both for the internal and for the external sites. We found that substrate selectivity is a decreasing function of temperature.
我们呈现了单组分乙烷和乙烯以及这两种气体等摩尔混合物在封闭的单壁碳纳米管束上吸附的蒙特卡罗模拟结果。在模拟中使用了两种类型的纳米管束：均匀的（即所有纳米管具有相同直径的纳米管束）和非均匀的（即允许不同直径的纳米管存在的纳米管束）。我们发现，在相同的压力和温度下，在整个压力和温度范围内，束上吸附的乙烷比乙烯多。对于等摩尔混合物的模拟结果表明，达到最大分离的压力是存在于束中的纳米管直径的非常敏感的函数。使用非均匀束进行的模拟比使用均匀束进行的模拟更能与单组分实验等温线和等比热数据吻合。讨论了纳米管在气体分离中的可能应用。我们研究了纳米管直径对这些吸附剂分离能力的影响，包括内部和外部位点。我们发现，基体质选择性是温度的递减函数。
