Friction drag of a spherical particle in a liquid crystal above the isotropic-nematic transition

Junichi Fukuda, Holger Stark, Hiroshi Yokoyama

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

We study the friction drag of a spherical particle in the isotropic phase of a nematic liquid crystal close to the isotropic-nematic transition point. To describe the orientational order in the liquid crystal, the second-rank tensor order parameter Qαβ is employed. We solve the hydrodynamic equations for Qαβ and the fluid velocity υ in order to determine the friction drag. In our discussion of the friction drag, we concentrate on four parameters: the temperature, the surface order parameter, the particle radius, and the Ericksen number Er (characterizing the ratio of the viscous force to the elastic force). The temperature dependence of the friction drag agrees well with experiments that show an increasing friction drag when the isotropic-nematic phase transition is approached from above. Furthermore the friction drag increases with the surface order parameter due to the more pronounced surface nematic layer, and for larger particles it is less affected by this layer. Finally, we observe that in the range of Er we study, the friction drag is almost independent of Er although flow-induced order occurs for sufficiently large Er and surface order parameter.

Original languageEnglish
Article number021701
JournalPhysical Review E - Statistical, Nonlinear, and Soft Matter Physics
Volume72
Issue number2
DOIs
Publication statusPublished - Aug 1 2005
Externally publishedYes

Fingerprint

friction drag
Drag
Liquid Crystal
Friction
liquid crystals
Order Parameter
Tensor Rank
Hydrodynamic Equations
hydrodynamic equations
Nematic Liquid Crystal
transition points
Temperature Dependence
surface layers
Phase Transition
Radius
tensors
Fluid
temperature dependence
radii
fluids

All Science Journal Classification (ASJC) codes

  • Statistical and Nonlinear Physics
  • Statistics and Probability
  • Condensed Matter Physics

Cite this

Friction drag of a spherical particle in a liquid crystal above the isotropic-nematic transition. / Fukuda, Junichi; Stark, Holger; Yokoyama, Hiroshi.

In: Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, Vol. 72, No. 2, 021701, 01.08.2005.

Research output: Contribution to journalArticle

@article{6723d05eb05b420d94ca1dfd4d66bca8,
title = "Friction drag of a spherical particle in a liquid crystal above the isotropic-nematic transition",
abstract = "We study the friction drag of a spherical particle in the isotropic phase of a nematic liquid crystal close to the isotropic-nematic transition point. To describe the orientational order in the liquid crystal, the second-rank tensor order parameter Qαβ is employed. We solve the hydrodynamic equations for Qαβ and the fluid velocity υ in order to determine the friction drag. In our discussion of the friction drag, we concentrate on four parameters: the temperature, the surface order parameter, the particle radius, and the Ericksen number Er (characterizing the ratio of the viscous force to the elastic force). The temperature dependence of the friction drag agrees well with experiments that show an increasing friction drag when the isotropic-nematic phase transition is approached from above. Furthermore the friction drag increases with the surface order parameter due to the more pronounced surface nematic layer, and for larger particles it is less affected by this layer. Finally, we observe that in the range of Er we study, the friction drag is almost independent of Er although flow-induced order occurs for sufficiently large Er and surface order parameter.",
author = "Junichi Fukuda and Holger Stark and Hiroshi Yokoyama",
year = "2005",
month = "8",
day = "1",
doi = "10.1103/PhysRevE.72.021701",
language = "English",
volume = "72",
journal = "Physical Review E",
issn = "2470-0045",
publisher = "American Physical Society",
number = "2",

}

TY - JOUR

T1 - Friction drag of a spherical particle in a liquid crystal above the isotropic-nematic transition

AU - Fukuda, Junichi

AU - Stark, Holger

AU - Yokoyama, Hiroshi

PY - 2005/8/1

Y1 - 2005/8/1

N2 - We study the friction drag of a spherical particle in the isotropic phase of a nematic liquid crystal close to the isotropic-nematic transition point. To describe the orientational order in the liquid crystal, the second-rank tensor order parameter Qαβ is employed. We solve the hydrodynamic equations for Qαβ and the fluid velocity υ in order to determine the friction drag. In our discussion of the friction drag, we concentrate on four parameters: the temperature, the surface order parameter, the particle radius, and the Ericksen number Er (characterizing the ratio of the viscous force to the elastic force). The temperature dependence of the friction drag agrees well with experiments that show an increasing friction drag when the isotropic-nematic phase transition is approached from above. Furthermore the friction drag increases with the surface order parameter due to the more pronounced surface nematic layer, and for larger particles it is less affected by this layer. Finally, we observe that in the range of Er we study, the friction drag is almost independent of Er although flow-induced order occurs for sufficiently large Er and surface order parameter.

AB - We study the friction drag of a spherical particle in the isotropic phase of a nematic liquid crystal close to the isotropic-nematic transition point. To describe the orientational order in the liquid crystal, the second-rank tensor order parameter Qαβ is employed. We solve the hydrodynamic equations for Qαβ and the fluid velocity υ in order to determine the friction drag. In our discussion of the friction drag, we concentrate on four parameters: the temperature, the surface order parameter, the particle radius, and the Ericksen number Er (characterizing the ratio of the viscous force to the elastic force). The temperature dependence of the friction drag agrees well with experiments that show an increasing friction drag when the isotropic-nematic phase transition is approached from above. Furthermore the friction drag increases with the surface order parameter due to the more pronounced surface nematic layer, and for larger particles it is less affected by this layer. Finally, we observe that in the range of Er we study, the friction drag is almost independent of Er although flow-induced order occurs for sufficiently large Er and surface order parameter.

UR - http://www.scopus.com/inward/record.url?scp=27244443714&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=27244443714&partnerID=8YFLogxK

U2 - 10.1103/PhysRevE.72.021701

DO - 10.1103/PhysRevE.72.021701

M3 - Article

VL - 72

JO - Physical Review E

JF - Physical Review E

SN - 2470-0045

IS - 2

M1 - 021701

ER -