
Experimental study of dynamic contact angles in liquid-liquid microfluidic plug flow with partial wetting
Author(s) -
Alexander Kovalev,
Anna A. Yagodnitsyna,
A. V. Bilsky
Publication year - 2020
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1677/1/012064
Subject(s) - wetting , contact angle , meniscus , mechanics , microchannel , materials science , flow (mathematics) , spark plug , microfluidics , plug flow , wetting transition , capillary number , optics , thermodynamics , capillary action , composite material , physics , nanotechnology , incidence (geometry)
Partial wetting of walls by immiscible liquids in microfluidic flows is a crucial parameter for heat and mass transfer applications. Dynamic contact angles, which characterize wettability, are studied experimentally for different liquid-liquid sets in microchannels with 200×400 μm and 120×240 μm cross-sections. An appropriate algorithm is chosen for meniscus shape approximation. Cox-Voinov law is found to predict correctly advancing contact angles in liquid-liquid flow. The generalized version of Cox-Voinov law is proposed for the liquid sets with different physical properties. Based on experimental data, new dependences of receding contact angle on contact line velocity are provided for the systems with concave and convex rear meniscus of a plug.