Invariant Fast Diffusion on the Surfaces of Ultrastable and Aged Molecular Glasses
| Autor: | Yue Zhang, Zahra Fakhraai |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Quenching
Surface diffusion Materials science Orders of magnitude (temperature) business.industry Diffusion Intermolecular force General Physics and Astronomy 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter::Disordered Systems and Neural Networks 01 natural sciences 0104 chemical sciences Optics Chemical physics Relaxation (physics) Particle 0210 nano-technology Glass transition business |
| Zdroj: | Physical review letters. 118(6) |
| ISSN: | 1079-7114 |
| Popis: | Surface diffusion of molecular glasses is found to be orders of magnitude faster than bulk diffusion, with a stronger dependence on the molecular size and intermolecular interactions. In this study, we investigate the effect of variations in bulk dynamics on the surface diffusion of molecular glasses. Using the tobacco mosaic virus as a probe particle, we measure the surface diffusion on glasses of the same composition but with orders of magnitude of variations in bulk relaxation dynamics, produced by physical vapor deposition, physical aging, and liquid quenching. The bulk fictive temperatures of these glasses span over 35 K, indicating 13 to 20 orders of magnitude changes in bulk relaxation times. However, the surface diffusion coefficients on these glasses are measured to be identical at two temperatures below the bulk glass transition temperature ${T}_{g}$. These results suggest that surface diffusion has no dependence on the bulk relaxation dynamics when measured below ${T}_{g}$. |
| Databáze: | OpenAIRE |
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