The influence of geometric heterogeneity of closed carbon nanotube bundles on benzene adsorption from the gaseous phase-Monte Carlo simulations

摘要

Benzene adsorption from the gaseous phase at 298 K and the thermodynamics of this process using Monte Carlo methods is studied. A series of closed single-walled carbon nanotube (SWCNT) bundles (triangular packing arrangement) with various distance between nanotubes is investigated. Isolated closed nanotube is treated as the reference system. Benzene is considered as a model compound to represent aromatics. Simulation results show the significant effect of the geometric heterogeneity on benzene adsorption as well as the enthalpy and entropy at low surface coverages. For insignificantly separated nanotubes and at low benzene uptakes, the entropy of the adsorbed phase is close to the entropy of solid benzene. Therefore, C6H6 molecules strongly interacting with walls are ordered in quasi-solid structures. At higher surface coverages, the ordering and packing of benzene molecules is liquid-like. The geometry of bundles (mutual position of SWCNTs) significantly influences the position and orientation of adsorbed molecules against the wall.