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An In Vitro Dissolution Determination of Multi-Index Components in Tibetan Medicine Rhodiola Granules
Published on: November 4, 2022
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Kinetics of Dissolution of an Amorphous Solid
Ian Douglass1, Peter Harrowell1
1School of Chemistry, University of Sydney , Sydney, NSW 2006, Australia.
The Journal of Physical Chemistry. B
|January 31, 2018
Summary
The dissolution rate of amorphous solids depends on surface particles ready to dissolve, not temperature or history. This study explores imaging these dynamic heterogeneities using surface etching.
Area of Science:
- Materials Science
- Physical Chemistry
- Solid-State Physics
Background:
- Amorphous solids exhibit dynamic heterogeneities due to relaxation processes at low temperatures.
- Understanding dissolution kinetics is crucial for materials processing and stability.
Purpose of the Study:
- To model and understand the dissolution kinetics of amorphous solids.
- To investigate the relationship between dynamic heterogeneities and dissolution rates.
- To explore surface etching as a method for visualizing these heterogeneities.
Main Methods:
- Development of a simple glass model to simulate amorphous material relaxation.
- Analysis of the intrinsic dissolution rate based on surface particle exchange.
- Characterization of the dissolving surface morphology.
Main Results:
- The intrinsic dissolution rate is directly proportional to the concentration of kinetically active surface particles.
- Dissolution rate is independent of temperature and the thermal history of the amorphous solid.
- Surface etching can potentially image dynamic heterogeneities.
Conclusions:
- Dissolution of amorphous solids is governed by the availability of reactive surface sites.
- Dynamic heterogeneities play a key role in the dissolution process.
- Surface etching offers a novel approach to study nanoscale dynamics in amorphous materials.
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