Delayed coalescence behavior of droplets with completely miscible liquids

Langmuir

Volumn 24, Issue 13, 2008, Pages 6395-6398

  Riegler, Hans ^a   Lazar, Paul ^a  

^a MAX PLANCK INSTITUTE OF COLLOIDS AND INTERFACES   (Germany)

Author keywords

[No Author keywords available]

Indexed keywords

CAPILLARITY; CONTACT ANGLE; DROP FORMATION; FLUID MECHANICS; FUSION REACTIONS; LIQUIDS; NUCLEAR PHYSICS; SEPARATION; SULFUR COMPOUNDS; SURFACE CHEMISTRY; SURFACE PROPERTIES; SURFACE TENSION; SURFACE WAVES; TURBULENCE; WETTING;

AMERICAN CHEMICAL SOCIETY (ACS); CAPILLARY FORCES; CAPILLARY PRESSURES; COALESCENCE BEHAVIOR; DROPLET FUSION; DYNAMIC PRESSURES; IN COMPOSITION; INITIAL CONTACT (IC); MISCIBLE LIQUIDS; SESSILE DROPLETS;

DROPS;

EID: 47349105259     PISSN: 07437463     EISSN: None     Source Type: Journal    
DOI: 10.1021/la800630w     Document Type: Article

References (20)

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13. Their explanation is as follows: (p 565) "The phenomenon (of a droplet of one liquid chasing one of a second liquid) is unquestionably connected with the one-sided effects of the vapours on the contact angles, already discussed. The adsorbed film surrounding the drop of the first liquid (which is pursued) induces the spreading of the pursuing drop in its direction".
14. The experiments with the delayed coalescence were performed with microscope slides as substrates. Untreated slides taken from a freshly opened package are perfect substrates wiui suitably small contact angles. If they are exposed to ambient air for some time, the contact angle will increase and the droplets will fuse instantaneously.
15. In fact, we first observed the delayed droplet fusion and the "chasing" droplets with sessile droplets of melts of altanes. Technically, these experiments were quite demanding. So, we decided to investigate the phenomena with the aqueous solutions which are experimentally easier to control.
16. Merkl, C.; Pfohl, T.; Riegler, H. Phys. Rev. Lett. 1997, 79(23), 4625-4628.
17. With alkanes, we also observe occasional pulsations as well as chasing droplets.
18. In reality, the neck between the two droplets is not nicely spherical. For the case of two droplets of the same liquid, see ref 8.
19. In reality, the gradient will be nonlinear and increase toward the high energy droplet because of the surface flow toward this droplet.
20. Guyon, E.; Hulin, J.-P.; Petit, L.; Mitescu; C. D. Physical Hydrodynamics; Oxford University Press: Oxford, 2001.