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Updated: Jul 26, 2025
09:26
Synthesis and Characterization of Supramolecular Colloids
Published on: April 22, 2016
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Colloidal Deposition by Polymer-Surfactant Complexes with Dilution and Shear
Lechuan Zhang1, Huda A Jerri2, Michael A Bevan1
1Chemical & Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States.
Langmuir : the ACS Journal of Surfaces and Colloids
|June 14, 2023
Summary
This study reveals how to control silica microparticle deposition on glass by tuning polymer-surfactant mixtures and shear rates. Informed design allows programming colloidal deposition for diverse applications.
Area of Science:
- Colloid and Surface Science
- Materials Science
- Polymer Chemistry
Background:
- Understanding colloidal particle deposition is crucial for material fabrication and surface modification.
- Polymer-surfactant interactions significantly influence colloidal behavior, affecting adhesion and stability.
- Controlling particle deposition under flow conditions remains a challenge in various industrial processes.
Purpose of the Study:
- To investigate the deposition, detachment, and redeposition dynamics of silica microparticles on glass substrates.
- To elucidate the role of cationic polymer-anionic surfactant composition and applied shear rate on particle behavior.
- To develop a method for programming colloidal deposition through controlled environmental conditions.
Main Methods:
- Utilized optical microscopy in a flow cell to observe silica microparticle behavior.
- Applied programmed shear and dilution profiles to induce and monitor deposition, detachment, and redeposition.
- Measured shear-dependent torque on particles to quantify adhesive forces mediated by polymer-surfactant complexes.
Main Results:
- Depletion-driven deposition at low shear rates (∼100 s⁻¹) detached easily due to weak adhesion.
- Particles resisted detachment up to higher shear rates (∼2000 s⁻¹) due to strong polymer bridging, likely from surfactant removal.
- Pathway dependence observed in polymer-surfactant de-complexation, leading to shear-resistant structures.
Conclusions:
- Colloidal deposition behavior can be programmed by carefully designing initial polymer-surfactant compositions and shear profiles.
- The developed particle trajectory analysis serves as a screening tool for composition-dependent colloidal deposition.
- Findings offer insights for tailored surface functionalization and advanced materials design.
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