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Density fluctuations of hard-sphere fluids in narrow confinement

Nygård, Kim; Sarman, Sten; Hyltegren, Kristin LU ; Chodankar, Shirish; Perret, Edith; Buitenhuis, Johan; van der Veen, J Friso and Kjellander, Roland (2016) In Physical Review X 6(1).
Abstract

Spatial confinement induces microscopic ordering of fluids, which in turn alters many of their dynamic and thermodynamic properties. However, the isothermal compressibility has hitherto been largely overlooked in the literature, despite its obvious connection to the underlying microscopic structure and density fluctuations in confined geometries. Here, we address this issue by probing density profiles and structure factors of hard-sphere fluids in various narrow slits, using x-ray scattering from colloid-filled nanofluidic containers and integral-equation-based statistical mechanics at the level of pair distributions for inhomogeneous fluids. Most importantly, we demonstrate that density fluctuations and isothermal compressibilities in... (More)

Spatial confinement induces microscopic ordering of fluids, which in turn alters many of their dynamic and thermodynamic properties. However, the isothermal compressibility has hitherto been largely overlooked in the literature, despite its obvious connection to the underlying microscopic structure and density fluctuations in confined geometries. Here, we address this issue by probing density profiles and structure factors of hard-sphere fluids in various narrow slits, using x-ray scattering from colloid-filled nanofluidic containers and integral-equation-based statistical mechanics at the level of pair distributions for inhomogeneous fluids. Most importantly, we demonstrate that density fluctuations and isothermal compressibilities in confined fluids can be obtained experimentally from the long-wavelength limit of the structure factor, providing a formally exact and experimentally accessible connection between microscopic structure and macroscopic, thermodynamic properties. Our approach will thus, for example, allow direct experimental verification of theoretically predicted enhanced density fluctuations in liquids near solvophobic interfaces.

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Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review X
volume
6
issue
1
publisher
American Physical Society
external identifiers
  • scopus:84984876814
  • wos:000370248600002
ISSN
2160-3308
DOI
10.1103/PhysRevX.6.011014
language
English
LU publication?
yes
id
2dbfdc26-7505-41f2-86ce-98c01918959b
date added to LUP
2017-02-07 12:03:22
date last changed
2017-11-05 05:13:18
@article{2dbfdc26-7505-41f2-86ce-98c01918959b,
  abstract     = {<p>Spatial confinement induces microscopic ordering of fluids, which in turn alters many of their dynamic and thermodynamic properties. However, the isothermal compressibility has hitherto been largely overlooked in the literature, despite its obvious connection to the underlying microscopic structure and density fluctuations in confined geometries. Here, we address this issue by probing density profiles and structure factors of hard-sphere fluids in various narrow slits, using x-ray scattering from colloid-filled nanofluidic containers and integral-equation-based statistical mechanics at the level of pair distributions for inhomogeneous fluids. Most importantly, we demonstrate that density fluctuations and isothermal compressibilities in confined fluids can be obtained experimentally from the long-wavelength limit of the structure factor, providing a formally exact and experimentally accessible connection between microscopic structure and macroscopic, thermodynamic properties. Our approach will thus, for example, allow direct experimental verification of theoretically predicted enhanced density fluctuations in liquids near solvophobic interfaces.</p>},
  articleno    = {011014},
  author       = {Nygård, Kim and Sarman, Sten and Hyltegren, Kristin and Chodankar, Shirish and Perret, Edith and Buitenhuis, Johan and van der Veen, J Friso and Kjellander, Roland},
  issn         = {2160-3308},
  language     = {eng},
  number       = {1},
  publisher    = {American Physical Society},
  series       = {Physical Review X},
  title        = {Density fluctuations of hard-sphere fluids in narrow confinement},
  url          = {http://dx.doi.org/10.1103/PhysRevX.6.011014},
  volume       = {6},
  year         = {2016},
}