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Particle deposition onto Janus and patchy spherical collectors
Reeshav Chatterjee1, Sushanta K Mitra, Subir Bhattacharjee
1Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada.
Langmuir : the ACS Journal of Surfaces and Colloids
|June 17, 2011
Summary
This study models colloid deposition on heterogeneous Janus and patchy collectors. Particle accumulation occurs at stripe edges, impacting porous media filtration and filter design.
Area of Science:
- Colloid and Surface Science
- Fluid Dynamics
- Environmental Engineering
Background:
- Colloid deposition is crucial for understanding particle transport in porous media.
- Surface charge heterogeneity significantly influences particle-collector interactions.
- Existing models often simplify collector surface properties.
Purpose of the Study:
- To develop an Eulerian model for colloid deposition on Janus and patchy collectors.
- To investigate the impact of surface charge heterogeneity on particle deposition rates.
- To analyze the effect of collector orientation and flow conditions on deposition patterns.
Main Methods:
- Utilized a convection-diffusion-migration equation within a Happel cell geometry.
- Modeled two surface charge distributions: Janus (half attractive, half repulsive) and patchy (alternating stripes).
- Incorporated variable fluid flow angles, including gravity-assisted and hindered conditions.
Main Results:
- Observed preferential particle deposition at the edges of attractive stripes on patchy collectors.
- Demonstrated that the extent of accumulation varies tangentially due to collector nonuniformity.
- Compared model predictions with a patchwise heterogeneity model.
Conclusions:
- Surface charge heterogeneity on collectors profoundly affects colloid deposition behavior.
- Chemically heterogeneous particles offer potential for enhanced particle capture in porous media.
- Findings can inform the design of more efficient and longer-lasting filter beds.
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