Early stage spreading: Mechanisms of rapid contact line advance

Edmund B. Webb, Baiou Shi

Research output: Contribution to journalReview article

8 Citations (Scopus)

Abstract

Inertial spreading occurs at the onset of a droplet wetting a solid; for low viscosity, highly wetting liquids, very high contact line velocities have been observed during this regime. Initial wetting kinetics are so rapid that careful experimental exploration of this phenomenon has only occurred over the past ~. 10. years. Herein, we review recent experimental and computational investigations into inertial spreading. We highlight results and discussion from literature that bear out an initially surprising conclusion: even nanometer scale drops exhibit a regime of early stage wetting kinetics that are well described as inertia dominated. Given this, some focus is placed on reviewing results from atomic scale simulations of inertial wetting and how they can be used to battle the lack of understanding regarding fundamental mechanisms of rapid contact line advancement. To bolster this discussion, new results are also presented from molecular dynamics simulations exploring inertial wetting in metallic systems. It is demonstrated that atomic scale simulations can reveal nanoscale size effects on inertial wetting and that, after accounting for these nanoscale effects, inertial regime spreading data for nanodrops are fully explained by otherwise continuum fluid mechanics theory. Data obtained are thus used to explore the role of order in liquid films near solid surfaces in controlling contact line advancement. In exploring the structure of an ordered liquid layer adjacent to the solid surface that undergoes significant slip during inertial spreading, it is demonstrated that a tensile strain gradient manifests in the layer as the film edge is approached.

Original languageEnglish (US)
Pages (from-to)255-265
Number of pages11
JournalCurrent Opinion in Colloid and Interface Science
Volume19
Issue number4
DOIs
StatePublished - Aug 1 2014

Fingerprint

wetting
Wetting
solid surfaces
Contacts (fluid mechanics)
liquids
continuum mechanics
Kinetics
Continuum mechanics
simulation
fluid mechanics
reviewing
Tensile strain
Fluid mechanics
kinetics
Liquid films
Liquids
bears
inertia
Molecular dynamics
slip

All Science Journal Classification (ASJC) codes

  • Surfaces and Interfaces
  • Physical and Theoretical Chemistry
  • Polymers and Plastics
  • Colloid and Surface Chemistry

Cite this

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abstract = "Inertial spreading occurs at the onset of a droplet wetting a solid; for low viscosity, highly wetting liquids, very high contact line velocities have been observed during this regime. Initial wetting kinetics are so rapid that careful experimental exploration of this phenomenon has only occurred over the past ~. 10. years. Herein, we review recent experimental and computational investigations into inertial spreading. We highlight results and discussion from literature that bear out an initially surprising conclusion: even nanometer scale drops exhibit a regime of early stage wetting kinetics that are well described as inertia dominated. Given this, some focus is placed on reviewing results from atomic scale simulations of inertial wetting and how they can be used to battle the lack of understanding regarding fundamental mechanisms of rapid contact line advancement. To bolster this discussion, new results are also presented from molecular dynamics simulations exploring inertial wetting in metallic systems. It is demonstrated that atomic scale simulations can reveal nanoscale size effects on inertial wetting and that, after accounting for these nanoscale effects, inertial regime spreading data for nanodrops are fully explained by otherwise continuum fluid mechanics theory. Data obtained are thus used to explore the role of order in liquid films near solid surfaces in controlling contact line advancement. In exploring the structure of an ordered liquid layer adjacent to the solid surface that undergoes significant slip during inertial spreading, it is demonstrated that a tensile strain gradient manifests in the layer as the film edge is approached.",
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Early stage spreading : Mechanisms of rapid contact line advance. / Webb, Edmund B.; Shi, Baiou.

In: Current Opinion in Colloid and Interface Science, Vol. 19, No. 4, 01.08.2014, p. 255-265.

Research output: Contribution to journalReview article

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AU - Shi, Baiou

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