Related Experiment Videos
Dissolution of crystallites: surface energetic control and size effects
Ruikang Tang1, Christine A Orme, George H Nancollas
1Department of Chemistry, Natural Sciences Complex, University at Buffalo, State University of New York, Buffalo, New York 14260, USA.
Summary
This study reveals critical conditions for crystal dissolution, involving pit formation and step displacement. These findings explain size-dependent dissolution phenomena like self-inhibition, challenging traditional theories.
Area of Science:
- Physical Chemistry
- Materials Science
- Crystallography
Background:
- Traditional dissolution theories assume spontaneous reactions reaching equilibrium.
- Existing models do not explain observed size-dependent dissolution phenomena.
Purpose of the Study:
- To present a new dissolution mechanism involving critical conditions.
- To explain size-effects in bulk dissolution using microscopic step dynamics.
Main Methods:
- Theoretical modeling of dissolution.
- Experimental verification of critical pits and step dynamics.
- Analysis of crystallite size effects on dissolution.
Main Results:
- Demonstrated critical conditions for dissolution with pit formation and step displacement.
- Established a relationship between step size and displacement rate, approaching zero at critical size r*.
- Observed size-effects including self-inhibition, dissolution suppression, and periodic resumption in crystallites near critical size.
Conclusions:
- Dissolution kinetics are energetically controlled at the molecular level.
- A new model for crystallite dissolution is proposed, explaining observed phenomena.
- Findings have implications for stabilizing biominerals and nanoparticles in undersaturated media.