Does confining the hard-sphere fluid between hard walls change its average properties?

@article{truskett07a, abstract = {We use grand canonical transition-matrix Monte Carlo and discontinuous molecular dynamics simulations to generate precise thermodynamic and kinetic data for the equilibrium hard-sphere fluid confined between smooth hard walls. These simulations show that the pronounced inhomogeneous structuring of the fluid normal to the confining walls, often the primary focus of density functional theory studies, has a negligible effect on many of its average properties over a surprisingly broad range of conditions. We present one consequence of this insensitivity to confinement: a simple analytical equation relating the average density of the confined fluid to that of the bulk fluid with equal activity. Nontrivial implications of confinement for average fluid properties do emerge in this system, but only when the fluid is both (i) dense and (ii) confined to a gap smaller than approximately three particle diameters. For this limited set of conditions, we find that “in-phase” oscillatory deviations in excess entropy and self-diffusivity (relative to the behavior of the bulk fluid at the same average density) occur as a function of gap size. These paired thermodynamic/kinetic deviations from bulk behavior appear to reflect the geometric packing frustration that arises when the confined space cannot naturally accommodate an integer number of particle layers. {\copyright}2007 American Institute of Physics}, author = {Mittal, Jeetain and Errington, Jeffrey R. and Truskett, Thomas M. }, citeulike-article-id = {1838165}, doi = {10.1063/1.2748045}, journal = {The Journal of Chemical Physics}, keywords = {confinement, hard-sphere, theory}, number = {24}, pages = {244708}, posted-at = {2007-10-30 01:06:41}, priority = {4}, publisher = {AIP}, title = {Does confining the hard-sphere fluid between hard walls change its average properties?}, url = {http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal\&id=JCPSA6000126000024244708000001\&idtype=cvips\&gifs=yes}, volume = {126}, year = {2007} }

TY - JOUR ID - truskett07a L3 - citeulike-article-id:1838165 TI - Does confining the hard-sphere fluid between hard walls change its average properties? JF - The Journal of Chemical Physics VL - 126 IS - 24 SP - 244708 EP - 244708 PB - AIP N2 - We use grand canonical transition-matrix Monte Carlo and discontinuous molecular dynamics simulations to generate precise thermodynamic and kinetic data for the equilibrium hard-sphere fluid confined between smooth hard walls. These simulations show that the pronounced inhomogeneous structuring of the fluid normal to the confining walls, often the primary focus of density functional theory studies, has a negligible effect on many of its average properties over a surprisingly broad range of conditions. We present one consequence of this insensitivity to confinement: a simple analytical equation relating the average density of the confined fluid to that of the bulk fluid with equal activity. Nontrivial implications of confinement for average fluid properties do emerge in this system, but only when the fluid is both (i) dense and (ii) confined to a gap smaller than approximately three particle diameters. For this limited set of conditions, we find that “in-phase” oscillatory deviations in excess entropy and self-diffusivity (relative to the behavior of the bulk fluid at the same average density) occur as a function of gap size. These paired thermodynamic/kinetic deviations from bulk behavior appear to reflect the geometric packing frustration that arises when the confined space cannot naturally accommodate an integer number of particle layers. ©2007 American Institute of Physics KW - confinement KW - hard-sphere KW - theory AU - Mittal, Jeetain AU - Errington, Jeffrey AU - Truskett, Thomas PY - 2007/// UR - http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JCPSA6000126000024244708000001&idtype=cvips&gifs=yes ER -