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Analysis of Contact Interactions between a Rough Deformable Colloid and a Smooth Substrate
1Department of Chemical, Bio and Materials Engineering, Arizona State University, Tempe, Arizona, 85287-6006
Journal of Colloid and Interface Science
|February 3, 2000
Summary
Colloid roughness significantly impacts removal force, according to a new model. This finding explains discrepancies in particle-surface interactions and aligns experimental data better than classical theories.
Area of Science:
- Colloid and Surface Science
- Nanotechnology
- Physical Chemistry
Background:
- Van der Waals interactions govern forces between colloids and surfaces.
- Colloid roughness is often overlooked but can influence interaction forces.
- Classical DLVO theory may not fully capture complex surface interactions.
Purpose of the Study:
- To develop a model for van der Waals forces considering colloid roughness.
- To investigate the impact of colloid roughness on removal force.
- To compare model predictions with experimental data and classical theories.
Main Methods:
- Developed a theoretical model for rough, deformable spherical colloids on a flat surface.
- Collected experimental data using Atomic Force Microscopy (AFM) for polystyrene latex colloids on silica substrates.
- Analyzed removal forces and compared them to model predictions and DLVO theory.
Main Results:
- Colloid roughness has a significant effect on the predicted removal force.
- Small variations in colloid roughness lead to substantial changes in removal force.
- The developed model bounds experimental removal force data and shows better agreement than DLVO theory.
Conclusions:
- Colloid roughness is a critical factor in particle-surface interactions.
- The new model provides a more accurate prediction of removal forces in systems with rough colloids.
- This work supports hypotheses attributing experimental discrepancies to colloid roughness.
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