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Confocal Imaging of Confined Quiescent and Flowing Colloid-polymer Mixtures
Published on: May 20, 2014
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Quantitative turbidimetric characterization of stabilized complex coacervate dispersions
Advait Holkar1, Shang Gao1, Kathleen Villaseñor1
1Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA. samsri@ucla.edu.
Soft Matter
|May 14, 2024
Summary
Comb polyelectrolyte (cPE) stabilizers enhance complex coacervate microdroplet stability and salt resistance. These cPEs effectively prevent droplet coalescence for extended periods, improving dispersion longevity.
Area of Science:
- Materials Science
- Colloid Science
- Polymer Chemistry
Background:
- Complex coacervates are liquid-liquid phase-separated systems with applications in bioreactors, drug delivery, and encapsulation.
- Stabilizing these coacervate microdroplets is crucial for their practical implementation.
- Existing stabilization methods often lack robustness or broad applicability.
Purpose of the Study:
- To quantitatively characterize the stability of complex coacervate dispersions using turbidimetry.
- To investigate the role of comb polyelectrolyte (cPE) stabilizers and salt concentration on dispersion stability.
- To explore the impact of cPEs on coacervate properties like size, number density, and salt resistance.
Main Methods:
- Turbidimetry measurements to monitor dispersion stability over time.
- Systematic variation of comb polyelectrolyte (cPE) and salt concentrations.
- Analysis of microdroplet size and number density.
- Generation of turbidity maps to visualize phase behavior and stability regions.
Main Results:
- Comb polyelectrolyte (cPE) stabilizers significantly enhance the stability of complex coacervate dispersions.
- cPEs effectively suppress microdroplet coalescence for at least 48 hours, even at high salt concentrations (up to 300 mM).
- Turbidity maps reveal an expanded two-phase region and a >3-fold increase in salt resistance, maintained for up to 15 days with cPE addition.
Conclusions:
- Comb polyelectrolytes (cPEs) are versatile and effective stabilizers for complex coacervate dispersions.
- cPEs impart significant and long-lasting salt resistance to coacervates, broadening their operational window.
- The findings enable better control over coacervate dispersion properties for advanced applications.
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