ISSN:
1089-7690
Quelle:
AIP Digital Archive
Thema:
Physik
,
Chemie und Pharmazie
Notizen:
The local structure of a Lennard-Jones fluid confined to a mesoscopic slit-pore with structureless (i.e., "smooth") walls is investigated by computing the local density ρ(z) in grand canonical ensemble Monte Carlo (GCEMC) simulations. For noncritical thermodynamic states of a corresponding bulk fluid, a homogeneous core region exists in the pore characterized by the bulk density ρbulk. Sufficiently close to the bulk critical point, however, the core is depleted, that is its local density ρcore(z) is less than ρbulk. Along a bulk near-critical isotherm T*=1.36(similar, equals)Tc,bulk* GCEMC data are analyzed in terms of the equations of state μbulk=μ(ρbulk,Tc,bulk) and μcore=μ(ρ¯mid,Tc,bulk), respectively, where ρ¯mid is the average midpoint density of the core fluid. At densities sufficiently above and below the bulk critical density thermodynamic states of core and bulk are the same, i.e. μbulk=μcore. However, if depletion is observed the density dependence of μbulk and μcore is generally different. By applying a mean-field theory to μbulk and μcore depletion is related to a reduced degree of criticality of the core fluid compared with the bulk phase in a self-contained way. © 1997 American Institute of Physics.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1063/1.474707
