Computer Simulations of Benzene Adsorbed on Graphite. 85-298 K

The structural and thermodynamic properties of benzene adsorbed on graphite have been determined by computer simulation. Two surface coverages were treated: a full √7 × √7 commensurate monolayer, and a layer with half this coverage. The temperature range of 85-298 K. included die two-dimensional melting regions. For the half layer, melting occurs sharply at T ≃ 145 K., but this phase transition is continuous over the approximate range 130-150 K. for the complete monolayer. The orientational disordering process occurs continuously for both systems, with considerably more disorder present at a given temperature for the full than for the half layer case. Surface liquid-vapor coexistence was observed for the half layer, beginning at the melting temperature and ending at ~205 K., close to the 2D critical temperature. © 1993, Kodansha Ltd.