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Updated: Aug 7, 2026
13:57
Preparation and Friction Force Microscopy Measurements of Immiscible, Opposing Polymer Brushes
Published on: December 24, 2014
Curved polymer and polyelectrolyte brushes beyond the Daoud-Cotton model
E B Zhulina1, T M Birshtein, O V Borisov
1Institute of Macromolecular Compounds of the Russian Academy of Sciences, 199004, St. Petersburg, Russia.
The European Physical Journal. E, Soft Matter
|July 25, 2006
Summary
We revised the Daoud-Cotton model for polymer brushes on curved surfaces. Our nonlocal approximation better predicts polymer density and free energy, especially for polyelectrolytes.
Area of Science:
- Polymer Physics
- Surface Science
- Physical Chemistry
Background:
- The Daoud-Cotton (DC) model describes polymer chains grafted to surfaces.
- Existing models may not accurately represent the free energy minimum of curved polymer brushes.
Purpose of the Study:
- To revise the classical Daoud-Cotton model for polymer and polyelectrolyte brushes on curved surfaces.
- To develop a nonlocal approximation that minimizes brush free energy.
Main Methods:
- Revision of the Daoud-Cotton model.
- Application of a nonlocal approximation to analyze polymer brush conformations.
- Comparison of model predictions for polymer density profiles and free energy.
Main Results:
- The nonlocal approximation predicts a polymer density profile that deviates from a single-exponent power law.
- In the limit of high surface curvature, scaling laws for brush thickness and free energy match the DC model, but with different prefactors.
- The nonlocal model predicts increased brush thickness and reduced free energy per chain due to chain extension.
Conclusions:
- The nonlocal approximation offers a more accurate description of curved polymer brushes, particularly for polyelectrolytes.
- Significant differences arise in predictions for pH-sensitive polyelectrolytes at low salinity.
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