Melting and crystallization of ice in partially filled nanopores

We investigate the melting and formation of ice in partially filled hydrophilic and hydrophobic nanopores of 3 nm diameter using molecular dynamics simulations with the mW water model. Above the melting temperature, the partially filled nanopores contain two water phases in coexistence: a condensed...

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Autores principales:	Gonzalez Solveyra, Estefania, De La Llave, Ezequiel Pablo, Molinero, Valeria Paula
Publicado:	2011
Materias:	Computer simulation Enthalpy Filling Hydrophilicity Hydrophobicity Liquids Melting point Metal melting Molecular dynamics Nanopores Phase transitions Bulk ice Bulk liquid Error bars Filling fractions Hydrophilic and hydrophobic Hydrophilic pores Hydrophobic and hydrophilic Hydrophobic pore Ice core Ice phase Liquid layer Liquid plugs Melting and crystallization Melting temperatures Molecular dynamics simulations Pore wall Water models Water phasis Ice
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15206106_v115_n48_p14196_GonzalezSolveyra http://hdl.handle.net/20.500.12110/paper_15206106_v115_n48_p14196_GonzalezSolveyra
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_15206106_v115_n48_p14196_GonzalezSolveyra
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spelling	paper:paper_15206106_v115_n48_p14196_GonzalezSolveyra2023-06-08T16:19:06Z Melting and crystallization of ice in partially filled nanopores Gonzalez Solveyra, Estefania De La Llave, Ezequiel Pablo Molinero, Valeria Paula Computer simulation Enthalpy Filling Hydrophilicity Hydrophobicity Liquids Melting point Metal melting Molecular dynamics Nanopores Phase transitions Bulk ice Bulk liquid Error bars Filling fractions Hydrophilic and hydrophobic Hydrophilic pores Hydrophobic and hydrophilic Hydrophobic pore Ice core Ice phase Liquid layer Liquid plugs Melting and crystallization Melting temperatures Molecular dynamics simulations Pore wall Water models Water phasis Ice We investigate the melting and formation of ice in partially filled hydrophilic and hydrophobic nanopores of 3 nm diameter using molecular dynamics simulations with the mW water model. Above the melting temperature, the partially filled nanopores contain two water phases in coexistence: a condensed liquid plug and a surface-adsorbed phase. It has been long debated in the literature whether the surface-adsorbed phase is involved in the crystallization. We find that only the liquid plug crystallizes on cooling, producing ice I with stacks of hexagonal and cubic layers. The confined ice is wetted by a premelted liquid layer that persists in equilibrium with ice down to temperatures well below its melting point. The liquid-ice transition is first-order-like but rounded. We determine the temperature and enthalpy of melting as a function of the filling fraction of the pore. In agreement with experiments, we find that the melting temperature of the nanoconfined ice is strongly depressed with respect to the bulk Tm, it depends weakly on the filling fraction and is insensitive to the hydrophobicity of the pore wall. The state of water in the crystallized hydrophilic and hydrophobic pores, however, is not the same: the hydrophobic pore has a negligible density of the surface-adsorbed phase and higher fraction of water in the ice phase than the hydrophilic pore. The widths of the ice cores are nevertheless comparable for the hydrophobic and hydrophilic pores, and this may explain their almost identical melting temperatures. The enthalpy of melting ΔHm, when normalized by the actual amount of ice in the pore, is indistinguishable for the hydrophobic and hydrophilic pores, insensitive to the filling fraction, and within the error bars, the same as the difference in enthalpy between bulk liquid and bulk ice evaluated at the temperature of melting of ice in the nanopores. © 2011 American Chemical Society. Fil:González Solveyra, E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:De La Llave, E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Molinero, V. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2011 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15206106_v115_n48_p14196_GonzalezSolveyra http://hdl.handle.net/20.500.12110/paper_15206106_v115_n48_p14196_GonzalezSolveyra
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Computer simulation Enthalpy Filling Hydrophilicity Hydrophobicity Liquids Melting point Metal melting Molecular dynamics Nanopores Phase transitions Bulk ice Bulk liquid Error bars Filling fractions Hydrophilic and hydrophobic Hydrophilic pores Hydrophobic and hydrophilic Hydrophobic pore Ice core Ice phase Liquid layer Liquid plugs Melting and crystallization Melting temperatures Molecular dynamics simulations Pore wall Water models Water phasis Ice
spellingShingle	Computer simulation Enthalpy Filling Hydrophilicity Hydrophobicity Liquids Melting point Metal melting Molecular dynamics Nanopores Phase transitions Bulk ice Bulk liquid Error bars Filling fractions Hydrophilic and hydrophobic Hydrophilic pores Hydrophobic and hydrophilic Hydrophobic pore Ice core Ice phase Liquid layer Liquid plugs Melting and crystallization Melting temperatures Molecular dynamics simulations Pore wall Water models Water phasis Ice Gonzalez Solveyra, Estefania De La Llave, Ezequiel Pablo Molinero, Valeria Paula Melting and crystallization of ice in partially filled nanopores
topic_facet	Computer simulation Enthalpy Filling Hydrophilicity Hydrophobicity Liquids Melting point Metal melting Molecular dynamics Nanopores Phase transitions Bulk ice Bulk liquid Error bars Filling fractions Hydrophilic and hydrophobic Hydrophilic pores Hydrophobic and hydrophilic Hydrophobic pore Ice core Ice phase Liquid layer Liquid plugs Melting and crystallization Melting temperatures Molecular dynamics simulations Pore wall Water models Water phasis Ice
description	We investigate the melting and formation of ice in partially filled hydrophilic and hydrophobic nanopores of 3 nm diameter using molecular dynamics simulations with the mW water model. Above the melting temperature, the partially filled nanopores contain two water phases in coexistence: a condensed liquid plug and a surface-adsorbed phase. It has been long debated in the literature whether the surface-adsorbed phase is involved in the crystallization. We find that only the liquid plug crystallizes on cooling, producing ice I with stacks of hexagonal and cubic layers. The confined ice is wetted by a premelted liquid layer that persists in equilibrium with ice down to temperatures well below its melting point. The liquid-ice transition is first-order-like but rounded. We determine the temperature and enthalpy of melting as a function of the filling fraction of the pore. In agreement with experiments, we find that the melting temperature of the nanoconfined ice is strongly depressed with respect to the bulk Tm, it depends weakly on the filling fraction and is insensitive to the hydrophobicity of the pore wall. The state of water in the crystallized hydrophilic and hydrophobic pores, however, is not the same: the hydrophobic pore has a negligible density of the surface-adsorbed phase and higher fraction of water in the ice phase than the hydrophilic pore. The widths of the ice cores are nevertheless comparable for the hydrophobic and hydrophilic pores, and this may explain their almost identical melting temperatures. The enthalpy of melting ΔHm, when normalized by the actual amount of ice in the pore, is indistinguishable for the hydrophobic and hydrophilic pores, insensitive to the filling fraction, and within the error bars, the same as the difference in enthalpy between bulk liquid and bulk ice evaluated at the temperature of melting of ice in the nanopores. © 2011 American Chemical Society.
author	Gonzalez Solveyra, Estefania De La Llave, Ezequiel Pablo Molinero, Valeria Paula
author_facet	Gonzalez Solveyra, Estefania De La Llave, Ezequiel Pablo Molinero, Valeria Paula
author_sort	Gonzalez Solveyra, Estefania
title	Melting and crystallization of ice in partially filled nanopores
title_short	Melting and crystallization of ice in partially filled nanopores
title_full	Melting and crystallization of ice in partially filled nanopores
title_fullStr	Melting and crystallization of ice in partially filled nanopores
title_full_unstemmed	Melting and crystallization of ice in partially filled nanopores
title_sort	melting and crystallization of ice in partially filled nanopores
publishDate	2011
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15206106_v115_n48_p14196_GonzalezSolveyra http://hdl.handle.net/20.500.12110/paper_15206106_v115_n48_p14196_GonzalezSolveyra
work_keys_str_mv	AT gonzalezsolveyraestefania meltingandcrystallizationoficeinpartiallyfillednanopores AT delallaveezequielpablo meltingandcrystallizationoficeinpartiallyfillednanopores AT molinerovaleriapaula meltingandcrystallizationoficeinpartiallyfillednanopores
_version_	1768546507562156032

Melting and crystallization of ice in partially filled nanopores

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