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Phase transitions of ordered ice in graphene nanocapillaries and carbon nanotubes

New phase diagrams for water confined in graphene nanocapillaries and single-walled carbon nanotubes (CNTs) are proposed, identifying ice structures, their melting points and revealing the presence of a solid-liquid critical point. For quasi-2D water in nanocapillaries, we show through molecular-dyn...

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Autores principales: Raju, Muralikrishna, van Duin, Adri, Ihme, Matthias
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5832794/
https://www.ncbi.nlm.nih.gov/pubmed/29497132
http://dx.doi.org/10.1038/s41598-018-22201-3
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author Raju, Muralikrishna
van Duin, Adri
Ihme, Matthias
author_facet Raju, Muralikrishna
van Duin, Adri
Ihme, Matthias
author_sort Raju, Muralikrishna
collection PubMed
description New phase diagrams for water confined in graphene nanocapillaries and single-walled carbon nanotubes (CNTs) are proposed, identifying ice structures, their melting points and revealing the presence of a solid-liquid critical point. For quasi-2D water in nanocapillaries, we show through molecular-dynamics simulations that AA stacking in multilayer quasi-2D ice arises from interlayer hydrogen-bonding and is stable up to three layers, thereby explaining recent experimental observations. Detailed structural and energetic analyses show that quasi-2D water can freeze discontinuously through a first-order phase transition or continuously with a critical point. The first-order transition line extends to a continuous transition line, defined by a sharp transition in diffusivity between solid-like and liquid-like regimes. For quasi-1D water, confined in CNTs, we observe the existence of a similar critical point at intermediate densities. In addition, an end point is identified on the continuous-transition line, above which the solid and liquid phases deform continuously. The solid-liquid phase transition temperatures in CNTs are shown to be substantially higher than 273 K, confirming recent Raman spectroscopy measurements. We observe ultrafast proton and hydroxyl transport in quasi-1D and -2D ice at 300 K, exceeding those of bulk water up to a factor of five, thereby providing possible applications to fuel-cells and electrolyzers.
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spelling pubmed-58327942018-03-05 Phase transitions of ordered ice in graphene nanocapillaries and carbon nanotubes Raju, Muralikrishna van Duin, Adri Ihme, Matthias Sci Rep Article New phase diagrams for water confined in graphene nanocapillaries and single-walled carbon nanotubes (CNTs) are proposed, identifying ice structures, their melting points and revealing the presence of a solid-liquid critical point. For quasi-2D water in nanocapillaries, we show through molecular-dynamics simulations that AA stacking in multilayer quasi-2D ice arises from interlayer hydrogen-bonding and is stable up to three layers, thereby explaining recent experimental observations. Detailed structural and energetic analyses show that quasi-2D water can freeze discontinuously through a first-order phase transition or continuously with a critical point. The first-order transition line extends to a continuous transition line, defined by a sharp transition in diffusivity between solid-like and liquid-like regimes. For quasi-1D water, confined in CNTs, we observe the existence of a similar critical point at intermediate densities. In addition, an end point is identified on the continuous-transition line, above which the solid and liquid phases deform continuously. The solid-liquid phase transition temperatures in CNTs are shown to be substantially higher than 273 K, confirming recent Raman spectroscopy measurements. We observe ultrafast proton and hydroxyl transport in quasi-1D and -2D ice at 300 K, exceeding those of bulk water up to a factor of five, thereby providing possible applications to fuel-cells and electrolyzers. Nature Publishing Group UK 2018-03-01 /pmc/articles/PMC5832794/ /pubmed/29497132 http://dx.doi.org/10.1038/s41598-018-22201-3 Text en © The Author(s) 2018 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
Raju, Muralikrishna
van Duin, Adri
Ihme, Matthias
Phase transitions of ordered ice in graphene nanocapillaries and carbon nanotubes
title Phase transitions of ordered ice in graphene nanocapillaries and carbon nanotubes
title_full Phase transitions of ordered ice in graphene nanocapillaries and carbon nanotubes
title_fullStr Phase transitions of ordered ice in graphene nanocapillaries and carbon nanotubes
title_full_unstemmed Phase transitions of ordered ice in graphene nanocapillaries and carbon nanotubes
title_short Phase transitions of ordered ice in graphene nanocapillaries and carbon nanotubes
title_sort phase transitions of ordered ice in graphene nanocapillaries and carbon nanotubes
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5832794/
https://www.ncbi.nlm.nih.gov/pubmed/29497132
http://dx.doi.org/10.1038/s41598-018-22201-3
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