Abstract
Although some differences have been observed, the transport behavior of radioactive aerosol particles has often been assumed to be analogous to the behavior of nonradioactive aerosols in dispersion models. However, radioactive particles can become electrostatically charged as a result of the decay process. Theories have been proposed to describe this self-charging phenomenon, which may have a significant effect on how these particles interact with one another and with charged surfaces in the environment. In this study, atomic force microscopy (AFM) was employed to quantify surface forces between a particle and a planar surface and to compare measurements with and without the involvement of radioactivity. The main objective of this work is to assess directly the effects of radioactivity on the surface interactions of radioactive aerosols via the measurement of the adhesion force. The adhesion force between a silicon nitride AFM tip and an activated gold substrate was measured so that any possible effects due to radioactivity could be observed. The adhesion force between the tip and the gold surface increased significantly when the gold substrate (25mm2 surface area) was activated to a level of approximately 0.6mCi. The results of this investigation will prompt further work into the effects of radioactivity in particle-surface interactions.
| Original language | English |
|---|---|
| Pages (from-to) | 595-598 |
| Number of pages | 4 |
| Journal | Journal of Colloid and Interface Science |
| Volume | 350 |
| Issue number | 2 |
| DOIs | |
| State | Published - Oct 2010 |
Funding
This work was sponsored by the Seed Money Fund of the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory (ORNL). Activation of the gold film was performed at the High Flux Isotope Reactor at ORNL. Partial support was provided by the National Science Foundation, under Grant CBET-0651683. The support that Dunbar Lockwood of DOE NA-243 provided to Mark Walker is also gratefully acknowledged. This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a nonexclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes.
Keywords
- AFM
- Adhesion force
- Particle transport
- Radioactivity
- Surface force