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Internal constraints and arrested relaxation in main-chain nematic elastomers
Nematic liquid crystal elastomers (N-LCE) exhibit intriguing mechanical properties, such as reversible actuation and soft elasticity, which manifests as a wide plateau of low nearly-constant stress upon stretching. N-LCE also have a characteristically slow stress relaxation, which sometimes prevents...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group UK
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7862651/ https://www.ncbi.nlm.nih.gov/pubmed/33542238 http://dx.doi.org/10.1038/s41467-021-21036-3 |
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author | Ohzono, Takuya Katoh, Kaoru Minamikawa, Hiroyuki Saed, Mohand O. Terentjev, Eugene M. |
author_facet | Ohzono, Takuya Katoh, Kaoru Minamikawa, Hiroyuki Saed, Mohand O. Terentjev, Eugene M. |
author_sort | Ohzono, Takuya |
collection | PubMed |
description | Nematic liquid crystal elastomers (N-LCE) exhibit intriguing mechanical properties, such as reversible actuation and soft elasticity, which manifests as a wide plateau of low nearly-constant stress upon stretching. N-LCE also have a characteristically slow stress relaxation, which sometimes prevents their shape recovery. To understand how the inherent nematic order retards and arrests the equilibration, here we examine hysteretic stress-strain characteristics in a series of specifically designed main-chain N-LCE, investigating both macroscopic mechanical properties and the microscopic nematic director distribution under applied strains. The hysteretic features are attributed to the dynamics of thermodynamically unfavoured hairpins, the sharp folds on anisotropic polymer strands, the creation and transition of which are restricted by the nematic order. These findings provide a new avenue for tuning the hysteretic nature of N-LCE at both macro- and microscopic levels via different designs of polymer networks, toward materials with highly nonlinear mechanical properties and shape-memory applications. |
format | Online Article Text |
id | pubmed-7862651 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-78626512021-02-16 Internal constraints and arrested relaxation in main-chain nematic elastomers Ohzono, Takuya Katoh, Kaoru Minamikawa, Hiroyuki Saed, Mohand O. Terentjev, Eugene M. Nat Commun Article Nematic liquid crystal elastomers (N-LCE) exhibit intriguing mechanical properties, such as reversible actuation and soft elasticity, which manifests as a wide plateau of low nearly-constant stress upon stretching. N-LCE also have a characteristically slow stress relaxation, which sometimes prevents their shape recovery. To understand how the inherent nematic order retards and arrests the equilibration, here we examine hysteretic stress-strain characteristics in a series of specifically designed main-chain N-LCE, investigating both macroscopic mechanical properties and the microscopic nematic director distribution under applied strains. The hysteretic features are attributed to the dynamics of thermodynamically unfavoured hairpins, the sharp folds on anisotropic polymer strands, the creation and transition of which are restricted by the nematic order. These findings provide a new avenue for tuning the hysteretic nature of N-LCE at both macro- and microscopic levels via different designs of polymer networks, toward materials with highly nonlinear mechanical properties and shape-memory applications. Nature Publishing Group UK 2021-02-04 /pmc/articles/PMC7862651/ /pubmed/33542238 http://dx.doi.org/10.1038/s41467-021-21036-3 Text en © The Author(s) 2021, corrected publication 2023 https://creativecommons.org/licenses/by/4.0/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/ (https://creativecommons.org/licenses/by/4.0/) . |
spellingShingle | Article Ohzono, Takuya Katoh, Kaoru Minamikawa, Hiroyuki Saed, Mohand O. Terentjev, Eugene M. Internal constraints and arrested relaxation in main-chain nematic elastomers |
title | Internal constraints and arrested relaxation in main-chain nematic elastomers |
title_full | Internal constraints and arrested relaxation in main-chain nematic elastomers |
title_fullStr | Internal constraints and arrested relaxation in main-chain nematic elastomers |
title_full_unstemmed | Internal constraints and arrested relaxation in main-chain nematic elastomers |
title_short | Internal constraints and arrested relaxation in main-chain nematic elastomers |
title_sort | internal constraints and arrested relaxation in main-chain nematic elastomers |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7862651/ https://www.ncbi.nlm.nih.gov/pubmed/33542238 http://dx.doi.org/10.1038/s41467-021-21036-3 |
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