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Giant electrocaloric response in smectic liquid crystals with direct smectic-isotropic transition

Electrocaloric materials have become a viable technology for solid state heat management applications. We demonstrate both theoretically and experimentally that liquid crystals (LCs) can be exploited as efficient electrocaloric materials. Numerical and experimental investigations determine the condi...

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Autores principales: Klemenčič, Eva, Trček, Maja, Kutnjak, Zdravko, Kralj, Samo
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6370888/
https://www.ncbi.nlm.nih.gov/pubmed/30742022
http://dx.doi.org/10.1038/s41598-019-38604-9
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author Klemenčič, Eva
Trček, Maja
Kutnjak, Zdravko
Kralj, Samo
author_facet Klemenčič, Eva
Trček, Maja
Kutnjak, Zdravko
Kralj, Samo
author_sort Klemenčič, Eva
collection PubMed
description Electrocaloric materials have become a viable technology for solid state heat management applications. We demonstrate both theoretically and experimentally that liquid crystals (LCs) can be exploited as efficient electrocaloric materials. Numerical and experimental investigations determine the conditions under which the strongest electrocaloric effect (ECE) responses are expected in LCs. Specifically, we show that a large ECE can be expected at the isotropic-nematic and in particular at the isotropic-smectic A phase transition. In our theoretical study, LC ordering is modelled using a Landau – de Gennes - Ginzburg mesoscopic approach. The simulation results are in qualitative agreement with our high precision electrocaloric measurements conducted on 8CB and 12CB liquid crystals. In the latter, we obtained ΔT(EC) ~ 6.5 K, corresponding to the largest response measured so far in LCs. The fluid property of LC electrocaloric heat cooling elements could lead to the development of devices with a higher coefficient of performance and thus better cooling power yield per mass of the ECE-based device.
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spelling pubmed-63708882019-02-15 Giant electrocaloric response in smectic liquid crystals with direct smectic-isotropic transition Klemenčič, Eva Trček, Maja Kutnjak, Zdravko Kralj, Samo Sci Rep Article Electrocaloric materials have become a viable technology for solid state heat management applications. We demonstrate both theoretically and experimentally that liquid crystals (LCs) can be exploited as efficient electrocaloric materials. Numerical and experimental investigations determine the conditions under which the strongest electrocaloric effect (ECE) responses are expected in LCs. Specifically, we show that a large ECE can be expected at the isotropic-nematic and in particular at the isotropic-smectic A phase transition. In our theoretical study, LC ordering is modelled using a Landau – de Gennes - Ginzburg mesoscopic approach. The simulation results are in qualitative agreement with our high precision electrocaloric measurements conducted on 8CB and 12CB liquid crystals. In the latter, we obtained ΔT(EC) ~ 6.5 K, corresponding to the largest response measured so far in LCs. The fluid property of LC electrocaloric heat cooling elements could lead to the development of devices with a higher coefficient of performance and thus better cooling power yield per mass of the ECE-based device. Nature Publishing Group UK 2019-02-11 /pmc/articles/PMC6370888/ /pubmed/30742022 http://dx.doi.org/10.1038/s41598-019-38604-9 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
Klemenčič, Eva
Trček, Maja
Kutnjak, Zdravko
Kralj, Samo
Giant electrocaloric response in smectic liquid crystals with direct smectic-isotropic transition
title Giant electrocaloric response in smectic liquid crystals with direct smectic-isotropic transition
title_full Giant electrocaloric response in smectic liquid crystals with direct smectic-isotropic transition
title_fullStr Giant electrocaloric response in smectic liquid crystals with direct smectic-isotropic transition
title_full_unstemmed Giant electrocaloric response in smectic liquid crystals with direct smectic-isotropic transition
title_short Giant electrocaloric response in smectic liquid crystals with direct smectic-isotropic transition
title_sort giant electrocaloric response in smectic liquid crystals with direct smectic-isotropic transition
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6370888/
https://www.ncbi.nlm.nih.gov/pubmed/30742022
http://dx.doi.org/10.1038/s41598-019-38604-9
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