Fluids in micropores. V. Effects of thermal motion in the walls of a slit-micropore

Journal Article · Wed May 01 04:00:00 EDT 1996 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.471345· OSTI ID:283348

Diestler, D J ^[1]; Schoen, M ^[2]

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1. Department of Agronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68583-0915 (United States)
2. Institut fuer Theoretische Physik, Technische Universitaet Berlin, Hardenbergstr. 36, 10623 Berlin (Germany)

Previous articles in this series have concerned the prototypal slit-pore with {ital rigid} walls, in which a Lennard-Jones (12,6) monatomic film is constrained between two plane-parallel walls comprising like atoms fixed in the face-centered-cubic (fcc) (100) configuration. The behavior of molecularly thin films in the rigid-wall prototype is governed by the template effect, whereby solid films can form epitaxially when the walls are properly aligned in the lateral directions. In this article the influence of thermal motion of the wall atoms on the template effect is investigated. The walls are treated as Einstein solids, the atoms moving independently in harmonic potentials centered on rigidly fixed equilibrium positions in the fcc (100) configuration. The force constant {ital f}{sub {ital c}} is a measure of the stiffness of the walls, the rigid-wall limit being {ital f}{sub {ital c}}={infinity}. Formal thermodynamic and statistical mechanical analyses of the system are carried out. The results of grand canonical ensemble Monte Carlo simulations indicate that for values of {ital f}{sub {ital c}} characteristic of a soft (e.g., noble-gas) crystal dynamic coupling between wall and film has a substantial influence on such equilibrium properties as normal stress (load) and interfacial tensions. In general, the softer the walls (i.e., the smaller the value of {ital f}{sub {ital c}}), the weaker the template effect and hence the softer and more disordered the confined film. {copyright} {ital 1996 American Institute of Physics.}

• DOE Contract Number: FG02-85ER60310
• OSTI ID: 283348
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 17 Vol. 104; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
COUPLING
EQUILIBRIUM
FLUIDS
HARMONIC POTENTIAL
LENNARD-JONES POTENTIAL
MICROSPORES
MONTE CARLO METHOD
MOTION
SIMULATION
THERMAL ANALYSIS
THIN FILMS
WALLS