Hostname: page-component-8448b6f56d-gtxcr Total loading time: 0 Render date: 2024-04-18T20:05:23.733Z Has data issue: false hasContentIssue false
  • English
  • Français

Liquid spreading on superhydrophilic micropillar arrays

Published online by Cambridge University Press:  20 June 2011

SEONG JIN KIM ,
MYOUNG-WOON MOON ,
KWANG-RYEOL LEE ,
DAE-YOUNG LEE ,
YOUNG SOO CHANG  and
HO-YOUNG KIM
SEONG JIN KIM
Affiliation:
School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-744, Korea
MYOUNG-WOON MOON
Affiliation:
Korea Institute of Science and Technology, Seoul 136-791, Korea
KWANG-RYEOL LEE
Affiliation:
Korea Institute of Science and Technology, Seoul 136-791, Korea
DAE-YOUNG LEE
Affiliation:
Korea Institute of Science and Technology, Seoul 136-791, Korea
YOUNG SOO CHANG
Affiliation:
Department of Advanced Fermentation Fusion Science and Technology, Kookmin University, Seoul 136-702, Korea
HO-YOUNG KIM*
Affiliation:
School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-744, Korea
*
†Email address for correspondence: hyk@snu.ac.kr
Get access Rights & Permissions [Opens in a new window]

Abstract

When a drop is deposited on a superhydrophilic micropillar array, the upper part of the drop (referred to as the bulk) collapses while the bottom part penetrates into the gaps of the array, forming a fringe film. Here we quantify the early stage dynamics of this process using a combination of experiment and theory. We show that the circular front of the fringe film spreads like t1/2, t being time, when coupled to the bulk flow. However, the film is found to advance like t1/3 through faceted zippering in the absence of the bulk. We then show that the spreading of the bulk and the entire drop footprint follows a power law (t1/4) that is different from Washburn's law. This work can be a starting point to completely understand the spreading of liquids on superhydrophilic surfaces and opens questions specific to superwetting behaviour including the criteria to determine whether the fringe film will expand through lateral zipping or advance radially outwards.

JFM classification

Interfacial Flows (free surface): Capillary flows Micro-/Nano-fluid dynamics: Microfluidics Interfacial Flows (free surface): Thin films
Type
Papers
Information
Journal of Fluid Mechanics , Volume 680 , 10 August 2011 , pp. 477 - 487
Copyright
Copyright © Cambridge University Press 2011

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Biance, A.-L., Clanet, C. & Quéré, D. 2004 First steps in the spreading of a liquid droplet. Phys. Rev. E 69, 016301.Google ScholarPubMed
Brochard-Wyart, F., Debrégeas, G. & de Gennes, P. G. 1996 Spreading of viscous droplets on a non viscous liquid. Colloid Polym. Sci. 274, 70–72.CrossRefGoogle Scholar
Cassie, A. B. D. & Baxter, S. 1944 Wettability of porous surfaces. Trans. Faraday Soc. 40, 546–551.CrossRefGoogle Scholar
Courbin, L., Denieul, E., Dressaire, E., Roper, M., Ajdari, A. & Stone, H. A. 2007 Imbibition by polygonal spreading on microdecorated surfaces. Nature Mater. 6, 660–664.CrossRefGoogle ScholarPubMed
de Gennes, P. G. 1985 Wetting: statics and dynamics. Rev. Mod. Phys. 57, 827–863.CrossRefGoogle Scholar
Ehrhard, P. 1993 Experiments on isothermal and non-isothermal spreading. J. Fluid Mech. 257, 463–483.CrossRefGoogle Scholar
Huppert, H. E. 1982 The propagation of two-dimensional and axisymmetric viscous gravity currents over a rigid horizontal surface. J. Fluid Mech. 121, 43–58.CrossRefGoogle Scholar
Ishino, C., Reyssat, M., Reyssat, E., Okumura, K. & Quéré, D. 2007 Wicking within forests of micropillars. Europhys. Lett. 79, 56005.CrossRefGoogle Scholar
Lopez, J. & Miller, C. A. 1976 Spreading kinetics of liquid drops on solids. J. Colloid Interface Sci. 56 (3), 460–468.CrossRefGoogle Scholar
Maclaine-cross, I. L. & Banks, P. J. 1981 A general theory of wet surface heat exchangers and its application to regenerative evaporative cooling. Trans. ASME J. Heat Transfer 103, 579–585.CrossRefGoogle Scholar
Martinez, A. W., Phillips, S. T. & Whitesides, G. M. 2008 Three-dimensional microfluidic devices fabricated in layered paper and tape. Proc. Natl Acad. Sci. USA 105, 19606–19611.CrossRefGoogle ScholarPubMed
McHale, G., Shirtcliffe, N. J., Aqil, S., Perry, C. C. & Newton, M. I. 2004 Topography driven spreading. Phys. Rev. Lett. 93, 036102.CrossRefGoogle ScholarPubMed
Reyssat, M., Courbin, L., Reyssat, E. & Stone, H. A. 2008 Imbibition in geometries with axial variations. J. Fluid Mech. 615, 335–344.CrossRefGoogle Scholar
Sbragaglia, M., Peters, A. M., Pirat, C., Borkent, B. M., Lammertink, R. G. H., Wessling, M. & Lohse, D. 2007 Spontaneous breakdown of superhydrophobicity. Phys. Rev. Lett. 99, 156001.CrossRefGoogle ScholarPubMed
Tanner, L. H. 1979 The spreading of silicone oil drops on horizontal surfaces. J. Phys. D: Appl. Phys. 12, 1473–1484.CrossRefGoogle Scholar
Teng, Y., Wang, R. Z. & Wu, J. Y. 1997 Study of the fundamentals of adsorption systems. Appl. Therm. Engng 17, 327–338.CrossRefGoogle Scholar
Washburn, E. W. 1921 The dynamics of capillary flow. Phys. Rev. 17, 273–283.CrossRefGoogle Scholar
Wenzel, R. N. 1936 Resistance of solid surfaces to wetting by water. Ind. Engng Chem. 28, 988–994.CrossRefGoogle Scholar
Yi, J. W., Moon, M.-W., Ahmed, S. F., Kim, H., Cha, T.-G., Kim, H.-Y., Kim, S.-S. & Lee, K.-R. 2010 Long-lasting hydrophilicity on nanostructured Si-incorporated diamond-like carbon films. Langmuir 26, 17203–17209.CrossRefGoogle ScholarPubMed