International Journal of Thermophysics

, Volume 26, Issue 6, pp 1743–1757 | Cite as

Dynamics of Drop Coalescence on a Surface: The Role of Initial Conditions and Surface Properties

Abstract

An investigation of the coalescence of two water drops on a surface is presented and compared with drop spreading. The associated capillary numbers are very low (< 10−5). The drops relax exponentially towards equilibrium. The typical relaxation time tc decreases with contact angle. tc is proportional to the drop size R, thus defining a characteristic velocity U* = R/tc. The corresponding U* values are smaller by many orders of magnitude than the bulk hydrodynamic velocity (U = σ /η, with σ the gas–liquid surface tension and η the viscosity). The dynamics of receding (coalescence) and spreading motion is found to be of the same order when coalescence or spreading is induced by a syringe. The dynamics of coalescence induced with the syringe deposition is systematically faster by an order of magnitude than condensation-induced coalescence. This disparity is explained by the coupling of the contact line motion with the oscillation of the drop observed for syringe deposition but absent for condensation-induced coalescence.

Keywords

capillary coalescence contact angle contact line velocity wetting 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Gennes, P. G. 1985Rev. Mod. Phys57827ADSGoogle Scholar
  2. 2.
    Voué, M., Valignat, M. P., Oshanin, G., Cazabat, A. M., Coninck, J. 1998Langmuir145951Google Scholar
  3. 3.
    Blake, T. D., Decamps, C., Coninck, J., Ruijter, M., Voué, M. 1999Colloids Surf., A1545CrossRefGoogle Scholar
  4. 4.
    Ruijter, M. J., De Coninck, J., Oshanin, G. 1999Langmuir152209Google Scholar
  5. 5.
    Ruijter, M. J., De Coninck, J., Blake, T. D., Clarke, A., Rainkin,  1997Langmuir137293Google Scholar
  6. 6.
    Blake, T. D., Haynes, J. M. 1969J. Colloid Interface Sci.30421CrossRefGoogle Scholar
  7. 7.
    Pomeau, Y. 2000C.R. Acad. Sci., Ser. IIb: Mec., Phys., Chim., Astron.238411Google Scholar
  8. 8.
    Andrieu, C., Beysens, D. A., Nikolayev, V. S., Pomeau, Y. 2002J. Fluid Mech.453427CrossRefADSMathSciNetGoogle Scholar
  9. 9.
    Zhao, H., Beysens, D. 1995Langmuir11627Google Scholar
  10. 10.
    Nikolayev, V. S., Beysens, D. A. 2002Phys. Rev. E6546135CrossRefADSGoogle Scholar
  11. 11.
    Nikolayev, V. S., Beysens, D. A. 2003Europhys. Lett.64763CrossRefADSGoogle Scholar
  12. 12.
    Nikolayev, V. S. 2005J. Phys.: Condens. Matter172111CrossRefADSGoogle Scholar
  13. 13.
    Rieutord, F., Rayssac, O., Moriceau, H. 2000Phys. Rev. E626861CrossRefADSGoogle Scholar
  14. 14.
    Iliev, S., Pesheva, N., Nikolayev, V. S. 2005Phys. Rev. E72011606CrossRefADSGoogle Scholar
  15. 15.
    Narhe, R., Beysens, D., Nikolayev, V. S. 2004Langmuir201213CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, Inc. 2005

Authors and Affiliations

  1. 1.ESEME, SBT, CEA-GrenobleFrance
  2. 2.CEA-ESEME, ESPCI-PMMHParis Cedex 5France

Personalised recommendations