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Updated: Dec 15, 2025
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Fast Imaging Technique to Study Drop Impact Dynamics of Non-Newtonian Fluids
Published on: March 5, 2014
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Water penetration dynamics through a Janus mesh during drop impact
Changwoo Bae1, Seungtae Oh1, Jeonghoon Han1
1Department of Mechanical Engineering, Kyung Hee University, Youngin 17104, Korea. ysnam1@khu.ac.kr cylee@khu.ac.kr.
Soft Matter
|July 9, 2020
Summary
Water penetration through Janus membranes involves two stages: rapid dynamic pressure and slower capillary pressure. Wettability impacts the initial penetration speed, crucial for designing membranes for water harvesting and separation.
Area of Science:
- Materials Science
- Fluid Dynamics
- Surface Chemistry
Background:
- Janus membranes possess distinct surface properties on opposing sides, enabling selective interactions.
- Understanding water penetration dynamics is key for applications like filtration and water management.
Purpose of the Study:
- To investigate the dynamics of water penetration through Janus membranes during drop impact.
- To elucidate the roles of dynamic and capillary pressures in water penetration.
- To explore the influence of surface wettability on penetration thresholds.
Main Methods:
- Experimental study of water drop impact on Janus membranes with contrasting wettabilities.
- Analysis of penetration dynamics based on timescales and pressure-driven mechanisms.
Main Results:
- Water penetration occurs in two distinct phases: dynamic pressure-driven (short timescale) and capillary pressure-driven (long timescale).
- The threshold impact velocity for penetration is lower when impacting the superhydrophobic side compared to the superhydrophilic side.
- Penetration under capillary pressure is governed by capillary and viscous pressures, occurring within a dynamically formed penetration area.
Conclusions:
- The interplay between dynamic and capillary pressures dictates water penetration through Janus membranes.
- Wettability significantly influences initial penetration dynamics, offering design flexibility.
- Findings support the development of Janus membranes for applications in oil-water separation, aeration, and water harvesting.
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