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Quantitative and Qualitative Examination of Particle-particle Interactions Using Colloidal Probe Nanoscopy
Published on: July 18, 2014
Influence of radioactivity on surface interaction forces
M E Walker1, J McFarlane, D C Glasgow
1Separations and Materials Research Group, Nuclear Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6181, USA.
Journal of Colloid and Interface Science
|July 24, 2010
Summary
Radioactive aerosol particles become electrostatically charged, affecting their interactions. This study used atomic force microscopy to show radioactivity significantly increases adhesion forces between particles and surfaces.
Area of Science:
- Environmental Science
- Materials Science
- Nuclear Physics
Background:
- Radioactive aerosol transport is often modeled assuming behavior similar to nonradioactive aerosols.
- Radioactive particles can develop electrostatic charges due to radioactive decay.
- This self-charging phenomenon may significantly alter particle interactions with surfaces and each other.
Purpose of the Study:
- To directly assess the impact of radioactivity on radioactive aerosol surface interactions.
- To quantify changes in adhesion force caused by particle self-charging.
- To compare surface force measurements with and without radioactivity.
Main Methods:
- Utilized atomic force microscopy (AFM) to measure surface forces.
- Quantified adhesion forces between a silicon nitride AFM tip and a gold substrate.
- Measured forces on an activated gold substrate (25 mm² surface area) at approximately 0.6 mCi radioactivity.
Main Results:
- A significant increase in adhesion force was observed between the AFM tip and the gold surface when the substrate was activated.
- Radioactivity demonstrably enhanced the particle-surface interaction, specifically adhesion.
- The findings provide direct experimental evidence of radioactivity's influence on aerosol-surface dynamics.
Conclusions:
- Radioactivity significantly impacts the adhesion forces of aerosol particles.
- The electrostatic charging of radioactive aerosols plays a crucial role in their surface interactions.
- Further research is warranted to fully understand radioactivity's effects on particle-surface dynamics in environmental contexts.
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