Interfacial forces and Marangoni flow on a nematic drop retracting in an isotropic fluid

Pengtao Yue, James J. Feng, Chun Liu, Jie Shen

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

Nematic-isotropic interfaces exhibit novel dynamics due to anchoring of the liquid crystal molecules on the interface. The objective of this study is to demonstrate the consequences of such dynamics in the flow field created by an elongated nematic drop retracting in an isotropic matrix. This is accomplished by two-dimensional flow simulations using a diffuse-interface model. By exploring the coupling among bulk liquid crystal orientation, surface anchoring and the flow field, we show that the anchoring energy plays a fundamental role in the interfacial dynamics of nematic liquids. In particular, it gives rise to a dynamic interfacial tension that depends on the bulk orientation. Tangential gradient of the interfacial tension drives a Marangoni flow near the nematic-isotropic interface. Besides, the anchoring energy produces an additional normal force on the interface that, together with the interfacial tension, determines the movement of the interface. Consequently, a nematic drop with planar anchoring retracts more slowly than a Newtonian drop, while one with homeotropic anchoring retracts faster than a Newtonian drop. The numerical results are consistent with prior theories for interfacial rheology and experimental observations.

Original languageEnglish (US)
Pages (from-to)281-288
Number of pages8
JournalJournal of Colloid And Interface Science
Volume290
Issue number1
DOIs
StatePublished - Oct 1 2005

Fingerprint

Surface tension
Liquid Crystals
Fluids
Liquid crystals
Flow fields
Flow simulation
Rheology
Crystal orientation
Molecules
Liquids

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Surfaces, Coatings and Films
  • Colloid and Surface Chemistry

Cite this

@article{31df286886124208bb3d402527f5d3d9,
title = "Interfacial forces and Marangoni flow on a nematic drop retracting in an isotropic fluid",
abstract = "Nematic-isotropic interfaces exhibit novel dynamics due to anchoring of the liquid crystal molecules on the interface. The objective of this study is to demonstrate the consequences of such dynamics in the flow field created by an elongated nematic drop retracting in an isotropic matrix. This is accomplished by two-dimensional flow simulations using a diffuse-interface model. By exploring the coupling among bulk liquid crystal orientation, surface anchoring and the flow field, we show that the anchoring energy plays a fundamental role in the interfacial dynamics of nematic liquids. In particular, it gives rise to a dynamic interfacial tension that depends on the bulk orientation. Tangential gradient of the interfacial tension drives a Marangoni flow near the nematic-isotropic interface. Besides, the anchoring energy produces an additional normal force on the interface that, together with the interfacial tension, determines the movement of the interface. Consequently, a nematic drop with planar anchoring retracts more slowly than a Newtonian drop, while one with homeotropic anchoring retracts faster than a Newtonian drop. The numerical results are consistent with prior theories for interfacial rheology and experimental observations.",
author = "Pengtao Yue and Feng, {James J.} and Chun Liu and Jie Shen",
year = "2005",
month = "10",
day = "1",
doi = "10.1016/j.jcis.2005.04.018",
language = "English (US)",
volume = "290",
pages = "281--288",
journal = "Journal of Colloid and Interface Science",
issn = "0021-9797",
publisher = "Academic Press Inc.",
number = "1",

}

Interfacial forces and Marangoni flow on a nematic drop retracting in an isotropic fluid. / Yue, Pengtao; Feng, James J.; Liu, Chun; Shen, Jie.

In: Journal of Colloid And Interface Science, Vol. 290, No. 1, 01.10.2005, p. 281-288.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Interfacial forces and Marangoni flow on a nematic drop retracting in an isotropic fluid

AU - Yue, Pengtao

AU - Feng, James J.

AU - Liu, Chun

AU - Shen, Jie

PY - 2005/10/1

Y1 - 2005/10/1

N2 - Nematic-isotropic interfaces exhibit novel dynamics due to anchoring of the liquid crystal molecules on the interface. The objective of this study is to demonstrate the consequences of such dynamics in the flow field created by an elongated nematic drop retracting in an isotropic matrix. This is accomplished by two-dimensional flow simulations using a diffuse-interface model. By exploring the coupling among bulk liquid crystal orientation, surface anchoring and the flow field, we show that the anchoring energy plays a fundamental role in the interfacial dynamics of nematic liquids. In particular, it gives rise to a dynamic interfacial tension that depends on the bulk orientation. Tangential gradient of the interfacial tension drives a Marangoni flow near the nematic-isotropic interface. Besides, the anchoring energy produces an additional normal force on the interface that, together with the interfacial tension, determines the movement of the interface. Consequently, a nematic drop with planar anchoring retracts more slowly than a Newtonian drop, while one with homeotropic anchoring retracts faster than a Newtonian drop. The numerical results are consistent with prior theories for interfacial rheology and experimental observations.

AB - Nematic-isotropic interfaces exhibit novel dynamics due to anchoring of the liquid crystal molecules on the interface. The objective of this study is to demonstrate the consequences of such dynamics in the flow field created by an elongated nematic drop retracting in an isotropic matrix. This is accomplished by two-dimensional flow simulations using a diffuse-interface model. By exploring the coupling among bulk liquid crystal orientation, surface anchoring and the flow field, we show that the anchoring energy plays a fundamental role in the interfacial dynamics of nematic liquids. In particular, it gives rise to a dynamic interfacial tension that depends on the bulk orientation. Tangential gradient of the interfacial tension drives a Marangoni flow near the nematic-isotropic interface. Besides, the anchoring energy produces an additional normal force on the interface that, together with the interfacial tension, determines the movement of the interface. Consequently, a nematic drop with planar anchoring retracts more slowly than a Newtonian drop, while one with homeotropic anchoring retracts faster than a Newtonian drop. The numerical results are consistent with prior theories for interfacial rheology and experimental observations.

UR - http://www.scopus.com/inward/record.url?scp=23944437416&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=23944437416&partnerID=8YFLogxK

U2 - 10.1016/j.jcis.2005.04.018

DO - 10.1016/j.jcis.2005.04.018

M3 - Article

C2 - 16122548

AN - SCOPUS:23944437416

VL - 290

SP - 281

EP - 288

JO - Journal of Colloid and Interface Science

JF - Journal of Colloid and Interface Science

SN - 0021-9797

IS - 1

ER -