Thermodynamics of a fluid confined to a slit pore with structured walls

D. J. Diestler, Martin Schoen, Joan E Curry, John H. Cushman

Research output: Contribution to journalArticle

48 Citations (Scopus)

Abstract

In this article we extend our previous thermodynamic analysis of films confined to slit pores with smooth walls (i.e., plane-parallel solid surfaces without molecular structure) to the situation in which the walls themselves possess structure. Structured-wall models are frequently employed to interpret experiments performed with the surface forces apparatus (SFA), in which thin films (1-10 molecular diameters thick) are subjected to shear stress by moving the walls laterally over one another at constant temperature, chemical potential, and normal stress or load. The periodic structure of the walls is reflected in a periodic variation of the shear stress with the lateral alignment (i.e., shear strain) of the walls. We demonstrate by means of a solvable two-dimensional model that the molecular length scale imposed by the structure of the walls precludes the derivation of a simple mechanical expression for the grand potential analogous to that which holds in the smooth-wall case. This conclusion is borne out by the results of a grand-canonical Monte Carlo simulation of the three-dimensional prototypal model consisting of a Leonard-Jones (12,6) fluid confined between fcc (100) walls. Criteria for the thermodynamic stability of thin films confined by structured walls are derived and applied to the SFA.

Original languageEnglish (US)
Pages (from-to)9140-9146
Number of pages7
JournalThe Journal of Chemical Physics
Volume100
Issue number12
StatePublished - 1994
Externally publishedYes

Fingerprint

slits
Thermodynamics
porosity
thermodynamics
Fluids
Shear stress
fluids
Thin films
Chemical potential
Periodic structures
Shear strain
Molecular structure
Loads (forces)
Thermodynamic stability
shear stress
Experiments
shear strain
three dimensional models
Temperature
thin films

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this

Diestler, D. J., Schoen, M., Curry, J. E., & Cushman, J. H. (1994). Thermodynamics of a fluid confined to a slit pore with structured walls. The Journal of Chemical Physics, 100(12), 9140-9146.

Thermodynamics of a fluid confined to a slit pore with structured walls. / Diestler, D. J.; Schoen, Martin; Curry, Joan E; Cushman, John H.

In: The Journal of Chemical Physics, Vol. 100, No. 12, 1994, p. 9140-9146.

Research output: Contribution to journalArticle

Diestler, DJ, Schoen, M, Curry, JE & Cushman, JH 1994, 'Thermodynamics of a fluid confined to a slit pore with structured walls', The Journal of Chemical Physics, vol. 100, no. 12, pp. 9140-9146.
Diestler, D. J. ; Schoen, Martin ; Curry, Joan E ; Cushman, John H. / Thermodynamics of a fluid confined to a slit pore with structured walls. In: The Journal of Chemical Physics. 1994 ; Vol. 100, No. 12. pp. 9140-9146.
@article{277b9f720369496fac19f6b6f6fd1b0d,
title = "Thermodynamics of a fluid confined to a slit pore with structured walls",
abstract = "In this article we extend our previous thermodynamic analysis of films confined to slit pores with smooth walls (i.e., plane-parallel solid surfaces without molecular structure) to the situation in which the walls themselves possess structure. Structured-wall models are frequently employed to interpret experiments performed with the surface forces apparatus (SFA), in which thin films (1-10 molecular diameters thick) are subjected to shear stress by moving the walls laterally over one another at constant temperature, chemical potential, and normal stress or load. The periodic structure of the walls is reflected in a periodic variation of the shear stress with the lateral alignment (i.e., shear strain) of the walls. We demonstrate by means of a solvable two-dimensional model that the molecular length scale imposed by the structure of the walls precludes the derivation of a simple mechanical expression for the grand potential analogous to that which holds in the smooth-wall case. This conclusion is borne out by the results of a grand-canonical Monte Carlo simulation of the three-dimensional prototypal model consisting of a Leonard-Jones (12,6) fluid confined between fcc (100) walls. Criteria for the thermodynamic stability of thin films confined by structured walls are derived and applied to the SFA.",
author = "Diestler, {D. J.} and Martin Schoen and Curry, {Joan E} and Cushman, {John H.}",
year = "1994",
language = "English (US)",
volume = "100",
pages = "9140--9146",
journal = "Journal of Chemical Physics",
issn = "0021-9606",
publisher = "American Institute of Physics Publising LLC",
number = "12",

}

TY - JOUR

T1 - Thermodynamics of a fluid confined to a slit pore with structured walls

AU - Diestler, D. J.

AU - Schoen, Martin

AU - Curry, Joan E

AU - Cushman, John H.

PY - 1994

Y1 - 1994

N2 - In this article we extend our previous thermodynamic analysis of films confined to slit pores with smooth walls (i.e., plane-parallel solid surfaces without molecular structure) to the situation in which the walls themselves possess structure. Structured-wall models are frequently employed to interpret experiments performed with the surface forces apparatus (SFA), in which thin films (1-10 molecular diameters thick) are subjected to shear stress by moving the walls laterally over one another at constant temperature, chemical potential, and normal stress or load. The periodic structure of the walls is reflected in a periodic variation of the shear stress with the lateral alignment (i.e., shear strain) of the walls. We demonstrate by means of a solvable two-dimensional model that the molecular length scale imposed by the structure of the walls precludes the derivation of a simple mechanical expression for the grand potential analogous to that which holds in the smooth-wall case. This conclusion is borne out by the results of a grand-canonical Monte Carlo simulation of the three-dimensional prototypal model consisting of a Leonard-Jones (12,6) fluid confined between fcc (100) walls. Criteria for the thermodynamic stability of thin films confined by structured walls are derived and applied to the SFA.

AB - In this article we extend our previous thermodynamic analysis of films confined to slit pores with smooth walls (i.e., plane-parallel solid surfaces without molecular structure) to the situation in which the walls themselves possess structure. Structured-wall models are frequently employed to interpret experiments performed with the surface forces apparatus (SFA), in which thin films (1-10 molecular diameters thick) are subjected to shear stress by moving the walls laterally over one another at constant temperature, chemical potential, and normal stress or load. The periodic structure of the walls is reflected in a periodic variation of the shear stress with the lateral alignment (i.e., shear strain) of the walls. We demonstrate by means of a solvable two-dimensional model that the molecular length scale imposed by the structure of the walls precludes the derivation of a simple mechanical expression for the grand potential analogous to that which holds in the smooth-wall case. This conclusion is borne out by the results of a grand-canonical Monte Carlo simulation of the three-dimensional prototypal model consisting of a Leonard-Jones (12,6) fluid confined between fcc (100) walls. Criteria for the thermodynamic stability of thin films confined by structured walls are derived and applied to the SFA.

UR - http://www.scopus.com/inward/record.url?scp=36449000756&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=36449000756&partnerID=8YFLogxK

M3 - Article

VL - 100

SP - 9140

EP - 9146

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 12

ER -