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Universal behavior of the apparent fragility in ultraslow glass forming systems
Despite decades of studies on the grand problem of the glass transition the question of well-defined universal patterns, including the key problem of the previtreous behavior of the primary (structural) relaxation time, remains elusive. This report shows the universal previtreous behavior of the app...
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Nature Publishing Group UK
2019
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6497650/ https://www.ncbi.nlm.nih.gov/pubmed/31048717 http://dx.doi.org/10.1038/s41598-019-42927-y |
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author | Drozd-Rzoska, Aleksandra |
author_facet | Drozd-Rzoska, Aleksandra |
author_sort | Drozd-Rzoska, Aleksandra |
collection | PubMed |
description | Despite decades of studies on the grand problem of the glass transition the question of well-defined universal patterns, including the key problem of the previtreous behavior of the primary (structural) relaxation time, remains elusive. This report shows the universal previtreous behavior of the apparent fragility, i.e. the steepness index m(P) (T > T(g)) = d log(10)τ(T)/d( T(g)/T). It is evidenced that m(P)(T) = 1(T − T*), for T → T(g) and T*= T(g) − Δ T*. Basing on this finding, the new 3-parameter dependence for portraying the previtreous behavior of the primary relaxation time has been derived: τ(T) = C(Ω)((T − T*)/T)(−Ω) × [exp((T − T*)/T)](Ω). The universality of obtained relations is evidenced for glass formers belonging to low molecular weight liquids, polymers (melt and solid), plastic crystals, liquid crystals, resins and relaxors. They exhibit clear preferences either for the VFT or for the critical-like descriptions, if recalled already used modeling. The novel relation can obey even above the dynamic crossover temperature, with the power exponent Ω ranging between ~17 (liquid crystals) to ~57 (glycerol), what may indicate the impact of symmetry on the previtreous effect. Finally, the emerging similarity to the behavior in the isotropic phase of nematic liquid crystals is recalled. |
format | Online Article Text |
id | pubmed-6497650 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-64976502019-05-17 Universal behavior of the apparent fragility in ultraslow glass forming systems Drozd-Rzoska, Aleksandra Sci Rep Article Despite decades of studies on the grand problem of the glass transition the question of well-defined universal patterns, including the key problem of the previtreous behavior of the primary (structural) relaxation time, remains elusive. This report shows the universal previtreous behavior of the apparent fragility, i.e. the steepness index m(P) (T > T(g)) = d log(10)τ(T)/d( T(g)/T). It is evidenced that m(P)(T) = 1(T − T*), for T → T(g) and T*= T(g) − Δ T*. Basing on this finding, the new 3-parameter dependence for portraying the previtreous behavior of the primary relaxation time has been derived: τ(T) = C(Ω)((T − T*)/T)(−Ω) × [exp((T − T*)/T)](Ω). The universality of obtained relations is evidenced for glass formers belonging to low molecular weight liquids, polymers (melt and solid), plastic crystals, liquid crystals, resins and relaxors. They exhibit clear preferences either for the VFT or for the critical-like descriptions, if recalled already used modeling. The novel relation can obey even above the dynamic crossover temperature, with the power exponent Ω ranging between ~17 (liquid crystals) to ~57 (glycerol), what may indicate the impact of symmetry on the previtreous effect. Finally, the emerging similarity to the behavior in the isotropic phase of nematic liquid crystals is recalled. Nature Publishing Group UK 2019-05-02 /pmc/articles/PMC6497650/ /pubmed/31048717 http://dx.doi.org/10.1038/s41598-019-42927-y Text en © The Author(s) 2019 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. |
spellingShingle | Article Drozd-Rzoska, Aleksandra Universal behavior of the apparent fragility in ultraslow glass forming systems |
title | Universal behavior of the apparent fragility in ultraslow glass forming systems |
title_full | Universal behavior of the apparent fragility in ultraslow glass forming systems |
title_fullStr | Universal behavior of the apparent fragility in ultraslow glass forming systems |
title_full_unstemmed | Universal behavior of the apparent fragility in ultraslow glass forming systems |
title_short | Universal behavior of the apparent fragility in ultraslow glass forming systems |
title_sort | universal behavior of the apparent fragility in ultraslow glass forming systems |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6497650/ https://www.ncbi.nlm.nih.gov/pubmed/31048717 http://dx.doi.org/10.1038/s41598-019-42927-y |
work_keys_str_mv | AT drozdrzoskaaleksandra universalbehavioroftheapparentfragilityinultraslowglassformingsystems |