Drops on soft solids: free energy and double transition of contact angles

@article{Lubbers2014DropsOS,
  title={Drops on soft solids: free energy and double transition of contact angles},
  author={L. Alrik Lubbers and Joost H. Weijs and Lorenzo Botto and S Das and Bruno Andreotti and Jacco H. Snoeijer},
  journal={Journal of Fluid Mechanics},
  year={2014},
  volume={747}
}
Abstract The equilibrium shape of liquid drops on elastic substrates is determined by minimizing elastic and capillary free energies, focusing on thick incompressible substrates. The problem is governed by three length scales: the size of the drop $R$ , the molecular size $a$ and the ratio of surface tension to elastic modulus $\gamma /E$ . We show that the contact angles undergo two transitions upon changing the substrate from rigid to soft. The microscopic wetting angles deviate from Young’s… Expand
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  • Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences
  • 2015
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References

SHOWING 1-10 OF 35 REFERENCES
Contact angles on a soft solid: from Young's law to Neumann's law.
TLDR
An elastocapillary model for contact angles on a soft solid is derived by coupling a mean-field model for the molecular interactions to elasticity and it is demonstrated that the limit of a vanishing elastic modulus yields Neumann's law or a variation thereof, depending on the force transmission in the solid surface layer. Expand
Static wetting on deformable substrates, from liquids to soft solids
Young's law fails on soft solid and liquid substrates where there are substantial deformations near the contact line. On liquid substrates, this is captured by Neumann's classic analysis, whichExpand
The contact angle on an elastic substrate. 1. The role of disjoining pressure in the surface mechanics
Abstract Using the correct physical mechanism for the transmission of the surface tension stress of a free liquid interface to the substrate, viz., the disjoining pressure of theExpand
Elasto-capillarity at the nanoscale: on the coupling between elasticity and surface energy in soft solids
The capillary forces exerted by liquid drops and bubbles on a soft solid are directly measured using molecular dynamics simulations. The force on the solid by the liquid near the contact line isExpand
Deformation of an elastic substrate by a three-phase contact line.
TLDR
This work measures surface and bulk deformation of a thin elastic film near a three-phase contact line using fluorescence confocal microscopy and predicts that the deformation profile near the contact line is scale-free and independent of the substrate elastic modulus. Expand
Universal deformation of soft substrates near a contact line and the direct measurement of solid surface stresses.
TLDR
Using confocal microscopy, this work measures the deformation of silicone gel substrates due to glycerol and fluorinated-oil droplets for a range of droplet radii and substrate thicknesses and shows that Young's law fails for small droplets when their radii approach an elastocapillary length scale. Expand
Contact angles of liquids at deformable solid surfaces
Abstract The relation between the contact angles and the interfacial tensions for a liquid droplet resting on a solid surface is examined. Neumann's triangle of forces is valid, in principle, forExpand
Straight contact lines on a soft, incompressible solid
  • L. Limat
  • Physics, Medicine
  • The European physical journal. E, Soft matter
  • 2012
TLDR
The deformation of a soft substrate by a straight contact line is calculated, and the result applied to a static rivulet between two parallel contact lines may have surprising implications for the modelling of hysteresis on systems having both plastic and elastic properties. Expand
Capillary pressure and contact line force on a soft solid.
TLDR
The results reveal the way the liquid pulls on the solid close to the contact line: the capillary force is not oriented along the liquid-air interface, nor perpendicularly to the solid surface, as previously hypothesized, but towards the interior of the liquid. Expand
The influence of solid micro-deformation on contact angle equilibrium
At a triple wetting line, the liquid-fluid tension may produce a wetting ridge in sufficiently soft solids. By employing variational methods, it has been shown that the solid strain combined with theExpand
...
1
2
3
4
...