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Fast Vibrational Modes and Slow Heterogeneous Dynamics in Polymers and Viscous Liquids
Many systems, including polymers and molecular liquids, when adequately cooled and/or compressed, solidify into a disordered solid, i.e., a glass. The transition is not abrupt, featuring progressive decrease of the microscopic mobility and huge slowing down of the relaxation. A distinctive aspect of...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6888094/ https://www.ncbi.nlm.nih.gov/pubmed/31739510 http://dx.doi.org/10.3390/ijms20225708 |
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author | Puosi, Francesco Tripodo, Antonio Leporini, Dino |
author_facet | Puosi, Francesco Tripodo, Antonio Leporini, Dino |
author_sort | Puosi, Francesco |
collection | PubMed |
description | Many systems, including polymers and molecular liquids, when adequately cooled and/or compressed, solidify into a disordered solid, i.e., a glass. The transition is not abrupt, featuring progressive decrease of the microscopic mobility and huge slowing down of the relaxation. A distinctive aspect of glass-forming materials is the microscopic dynamical heterogeneity (DH), i.e., the presence of regions with almost immobile particles coexisting with others where highly mobile ones are located. Following the first compelling evidence of a strong correlation between vibrational dynamics and ultraslow relaxation, we posed the question if the vibrational dynamics encodes predictive information on DH. Here, we review our results, drawn from molecular-dynamics numerical simulation of polymeric and molecular glass-formers, with a special focus on both the breakdown of the Stokes–Einstein relation between diffusion and viscosity, and the size of the regions with correlated displacements. |
format | Online Article Text |
id | pubmed-6888094 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-68880942019-12-09 Fast Vibrational Modes and Slow Heterogeneous Dynamics in Polymers and Viscous Liquids Puosi, Francesco Tripodo, Antonio Leporini, Dino Int J Mol Sci Review Many systems, including polymers and molecular liquids, when adequately cooled and/or compressed, solidify into a disordered solid, i.e., a glass. The transition is not abrupt, featuring progressive decrease of the microscopic mobility and huge slowing down of the relaxation. A distinctive aspect of glass-forming materials is the microscopic dynamical heterogeneity (DH), i.e., the presence of regions with almost immobile particles coexisting with others where highly mobile ones are located. Following the first compelling evidence of a strong correlation between vibrational dynamics and ultraslow relaxation, we posed the question if the vibrational dynamics encodes predictive information on DH. Here, we review our results, drawn from molecular-dynamics numerical simulation of polymeric and molecular glass-formers, with a special focus on both the breakdown of the Stokes–Einstein relation between diffusion and viscosity, and the size of the regions with correlated displacements. MDPI 2019-11-14 /pmc/articles/PMC6888094/ /pubmed/31739510 http://dx.doi.org/10.3390/ijms20225708 Text en © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Review Puosi, Francesco Tripodo, Antonio Leporini, Dino Fast Vibrational Modes and Slow Heterogeneous Dynamics in Polymers and Viscous Liquids |
title | Fast Vibrational Modes and Slow Heterogeneous Dynamics in Polymers and Viscous Liquids |
title_full | Fast Vibrational Modes and Slow Heterogeneous Dynamics in Polymers and Viscous Liquids |
title_fullStr | Fast Vibrational Modes and Slow Heterogeneous Dynamics in Polymers and Viscous Liquids |
title_full_unstemmed | Fast Vibrational Modes and Slow Heterogeneous Dynamics in Polymers and Viscous Liquids |
title_short | Fast Vibrational Modes and Slow Heterogeneous Dynamics in Polymers and Viscous Liquids |
title_sort | fast vibrational modes and slow heterogeneous dynamics in polymers and viscous liquids |
topic | Review |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6888094/ https://www.ncbi.nlm.nih.gov/pubmed/31739510 http://dx.doi.org/10.3390/ijms20225708 |
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