Surface-Tension-Driven Dynamic Contact Line in Microgravity

We study the effect of Marangoni flow on a dynamic contact line formed by a propagating reaction front and a liquid-air interface. The self-sustained iodate-arsenous acid reaction maintains the production of the weakly surface active iodine leading to an unbalanced surface force along the tip of the...

Teljes leírás

Elmentve itt :
Bibliográfiai részletek
Szerzők: Bába Péter
Tóth Ágota
Horváth Dezső
Dokumentumtípus: Cikk
Megjelent: 2019
Sorozat:LANGMUIR 35 No. 2
doi:10.1021/acs.langmuir.8b03592

mtmt:30443568
Online Access:http://publicatio.bibl.u-szeged.hu/15383
Leíró adatok
Tartalmi kivonat:We study the effect of Marangoni flow on a dynamic contact line formed by a propagating reaction front and a liquid-air interface. The self-sustained iodate-arsenous acid reaction maintains the production of the weakly surface active iodine leading to an unbalanced surface force along the tip of the reaction front. The experiments, performed in microgravity to exclude the contribution of buoyancy, reveal that the fluid flow generated by the surface tension gradient is localized to the contact line. The penetration depth of the surface stress is measured as 1-2 mm; therefore, with greater fluid height the liquid advancement on the upper surface does not lead to enhanced mixing in the bulk. Because the propagation velocity of the reactive interface remains at that of reaction-diffusion, the leading edge consists of two straight lines; a tilted segment connects the contact line on the surface with the vertical segment on bottom. Modeling calculations of the reaction-diffusion-advection system in three dimensions reconstruct the experimental observations and along with the experiments validate a model based on geometric spreading. According to the calculated flow field, the direction of significant fluid flow follows the concentration gradients and hence coincides with the propagation of the reaction front, allowing only negligible transverse flow in the upper fluid layer.
Terjedelem/Fizikai jellemzők:406-412
ISSN:0743-7463