Vapor pressure of water nanodroplets

Classical thermodynamics is assumed to be valid up to a certain length-scale, below which the discontinuous nature of matter becomes manifest. In particular, this must be the case for the description of the vapor pressure based on the Kelvin equation. However, the legitimacy of this equation in the...

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Autores principales: Factorovich, M.H., Molinero, V., Scherlis, D.A.
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00027863_v136_n12_p4508_Factorovich
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spelling todo:paper_00027863_v136_n12_p4508_Factorovich2023-10-03T13:54:23Z Vapor pressure of water nanodroplets Factorovich, M.H. Molinero, V. Scherlis, D.A. Drop formation Hydrostatic pressure Molecular dynamics Thermodynamics Vapors Classical thermodynamics Density profile Grand canonical Kelvin equation Molecular descriptions Molecular dynamics simulations Pressure of water Screening approaches Vapor pressure water article evaporation high temperature molecular dynamics particle size surface tension thermodynamics transition temperature vapor pressure water vapor Classical thermodynamics is assumed to be valid up to a certain length-scale, below which the discontinuous nature of matter becomes manifest. In particular, this must be the case for the description of the vapor pressure based on the Kelvin equation. However, the legitimacy of this equation in the nanoscopic regime can not be simply established, because the determination of the vapor pressure of very small droplets poses a challenge both for experiments and simulations. In this article we make use of a grand canonical screening approach recently proposed to compute the vapor pressures of finite systems from molecular dynamics simulations. This scheme is applied to water droplets, to show that the applicability of the Kelvin equation extends to unexpectedly small lengths, of only 1 nm, where the inhomogeneities in the density of matter occur within spatial lengths of the same order of magnitude as the size of the object. While in principle this appears to violate the main assumptions underlying thermodynamics, the density profiles reveal, however, that structures of this size are still homogeneous in the nanosecond time-scale. Only when the inhomogeneity in the density persists through the temporal average, as it is the case for clusters of 40 particles or less, do the macroscopic thermodynamics and the molecular descriptions depart from each other. © 2014 American Chemical Society. Fil:Molinero, V. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00027863_v136_n12_p4508_Factorovich
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Drop formation
Hydrostatic pressure
Molecular dynamics
Thermodynamics
Vapors
Classical thermodynamics
Density profile
Grand canonical
Kelvin equation
Molecular descriptions
Molecular dynamics simulations
Pressure of water
Screening approaches
Vapor pressure
water
article
evaporation
high temperature
molecular dynamics
particle size
surface tension
thermodynamics
transition temperature
vapor pressure
water vapor
spellingShingle Drop formation
Hydrostatic pressure
Molecular dynamics
Thermodynamics
Vapors
Classical thermodynamics
Density profile
Grand canonical
Kelvin equation
Molecular descriptions
Molecular dynamics simulations
Pressure of water
Screening approaches
Vapor pressure
water
article
evaporation
high temperature
molecular dynamics
particle size
surface tension
thermodynamics
transition temperature
vapor pressure
water vapor
Factorovich, M.H.
Molinero, V.
Scherlis, D.A.
Vapor pressure of water nanodroplets
topic_facet Drop formation
Hydrostatic pressure
Molecular dynamics
Thermodynamics
Vapors
Classical thermodynamics
Density profile
Grand canonical
Kelvin equation
Molecular descriptions
Molecular dynamics simulations
Pressure of water
Screening approaches
Vapor pressure
water
article
evaporation
high temperature
molecular dynamics
particle size
surface tension
thermodynamics
transition temperature
vapor pressure
water vapor
description Classical thermodynamics is assumed to be valid up to a certain length-scale, below which the discontinuous nature of matter becomes manifest. In particular, this must be the case for the description of the vapor pressure based on the Kelvin equation. However, the legitimacy of this equation in the nanoscopic regime can not be simply established, because the determination of the vapor pressure of very small droplets poses a challenge both for experiments and simulations. In this article we make use of a grand canonical screening approach recently proposed to compute the vapor pressures of finite systems from molecular dynamics simulations. This scheme is applied to water droplets, to show that the applicability of the Kelvin equation extends to unexpectedly small lengths, of only 1 nm, where the inhomogeneities in the density of matter occur within spatial lengths of the same order of magnitude as the size of the object. While in principle this appears to violate the main assumptions underlying thermodynamics, the density profiles reveal, however, that structures of this size are still homogeneous in the nanosecond time-scale. Only when the inhomogeneity in the density persists through the temporal average, as it is the case for clusters of 40 particles or less, do the macroscopic thermodynamics and the molecular descriptions depart from each other. © 2014 American Chemical Society.
format JOUR
author Factorovich, M.H.
Molinero, V.
Scherlis, D.A.
author_facet Factorovich, M.H.
Molinero, V.
Scherlis, D.A.
author_sort Factorovich, M.H.
title Vapor pressure of water nanodroplets
title_short Vapor pressure of water nanodroplets
title_full Vapor pressure of water nanodroplets
title_fullStr Vapor pressure of water nanodroplets
title_full_unstemmed Vapor pressure of water nanodroplets
title_sort vapor pressure of water nanodroplets
url http://hdl.handle.net/20.500.12110/paper_00027863_v136_n12_p4508_Factorovich
work_keys_str_mv AT factorovichmh vaporpressureofwaternanodroplets
AT molinerov vaporpressureofwaternanodroplets
AT scherlisda vaporpressureofwaternanodroplets
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