Sorption isotherms of water in nanopores: Relationship between hydropohobicity, adsorption pressure, and hysteresis
The motivation of this study is to elucidate how the condensation and desorption pressures in water sorption isotherms depend on the contact angle. This question is investigated for cylindrical pores of 2.8 nm diameter by means of molecular dynamics simulations in the grand canonical ensemble, in co...
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2014
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paper:paper_19327447_v118_n29_p16290_Factorovich2023-06-08T16:31:35Z Sorption isotherms of water in nanopores: Relationship between hydropohobicity, adsorption pressure, and hysteresis Gonzalez Solveyra, Estefania Molinero, Valeria Paula Adsorption Adsorption isotherms Condensation Desorption Hysteresis Molecular dynamics Nanopores Adsorption and desorptions Capillary condensation Coarse grained models Condensation pressure Grand canonical ensemble Heterogeneous cavitation Molecular dynamics simulations Water sorption isotherms Contact angle The motivation of this study is to elucidate how the condensation and desorption pressures in water sorption isotherms depend on the contact angle. This question is investigated for cylindrical pores of 2.8 nm diameter by means of molecular dynamics simulations in the grand canonical ensemble, in combination with the mW coarse-grained model for water. The contact angle is characterized for different sets of water-surface interactions. First, we show that desorption in open-ended pores with moderate or low water affinity, with contact angles greater or equal than 24°, is a nonactivated process in which pressure is accurately described by the Kelvin equation. Then, we explore the influence of hydrophobicity on the capillary condensation and on the width of the hysteresis loop. We find that a small increase in the contact angle may have a significant impact on the surface density and consequently on the nucleation free energy barrier. This produces a separation of the adsorption and desorption branches, exacerbating the emerging hysteresis. These results suggest that the contact angle is not as relevant as the adsorption energy in determining condensation pressure and hysteresis. Finally, we consider nonequilibrium desorption in pores with no open ends and describe how homogeneous and heterogeneous cavitation mechanisms depend on hydrophilicity. © 2014 American Chemical Society. Fil:Gonzalez Solveyra, 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. 2014 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19327447_v118_n29_p16290_Factorovich http://hdl.handle.net/20.500.12110/paper_19327447_v118_n29_p16290_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 |
Adsorption Adsorption isotherms Condensation Desorption Hysteresis Molecular dynamics Nanopores Adsorption and desorptions Capillary condensation Coarse grained models Condensation pressure Grand canonical ensemble Heterogeneous cavitation Molecular dynamics simulations Water sorption isotherms Contact angle |
| spellingShingle |
Adsorption Adsorption isotherms Condensation Desorption Hysteresis Molecular dynamics Nanopores Adsorption and desorptions Capillary condensation Coarse grained models Condensation pressure Grand canonical ensemble Heterogeneous cavitation Molecular dynamics simulations Water sorption isotherms Contact angle Gonzalez Solveyra, Estefania Molinero, Valeria Paula Sorption isotherms of water in nanopores: Relationship between hydropohobicity, adsorption pressure, and hysteresis |
| topic_facet |
Adsorption Adsorption isotherms Condensation Desorption Hysteresis Molecular dynamics Nanopores Adsorption and desorptions Capillary condensation Coarse grained models Condensation pressure Grand canonical ensemble Heterogeneous cavitation Molecular dynamics simulations Water sorption isotherms Contact angle |
| description |
The motivation of this study is to elucidate how the condensation and desorption pressures in water sorption isotherms depend on the contact angle. This question is investigated for cylindrical pores of 2.8 nm diameter by means of molecular dynamics simulations in the grand canonical ensemble, in combination with the mW coarse-grained model for water. The contact angle is characterized for different sets of water-surface interactions. First, we show that desorption in open-ended pores with moderate or low water affinity, with contact angles greater or equal than 24°, is a nonactivated process in which pressure is accurately described by the Kelvin equation. Then, we explore the influence of hydrophobicity on the capillary condensation and on the width of the hysteresis loop. We find that a small increase in the contact angle may have a significant impact on the surface density and consequently on the nucleation free energy barrier. This produces a separation of the adsorption and desorption branches, exacerbating the emerging hysteresis. These results suggest that the contact angle is not as relevant as the adsorption energy in determining condensation pressure and hysteresis. Finally, we consider nonequilibrium desorption in pores with no open ends and describe how homogeneous and heterogeneous cavitation mechanisms depend on hydrophilicity. © 2014 American Chemical Society. |
| author |
Gonzalez Solveyra, Estefania Molinero, Valeria Paula |
| author_facet |
Gonzalez Solveyra, Estefania Molinero, Valeria Paula |
| author_sort |
Gonzalez Solveyra, Estefania |
| title |
Sorption isotherms of water in nanopores: Relationship between hydropohobicity, adsorption pressure, and hysteresis |
| title_short |
Sorption isotherms of water in nanopores: Relationship between hydropohobicity, adsorption pressure, and hysteresis |
| title_full |
Sorption isotherms of water in nanopores: Relationship between hydropohobicity, adsorption pressure, and hysteresis |
| title_fullStr |
Sorption isotherms of water in nanopores: Relationship between hydropohobicity, adsorption pressure, and hysteresis |
| title_full_unstemmed |
Sorption isotherms of water in nanopores: Relationship between hydropohobicity, adsorption pressure, and hysteresis |
| title_sort |
sorption isotherms of water in nanopores: relationship between hydropohobicity, adsorption pressure, and hysteresis |
| publishDate |
2014 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19327447_v118_n29_p16290_Factorovich http://hdl.handle.net/20.500.12110/paper_19327447_v118_n29_p16290_Factorovich |
| work_keys_str_mv |
AT gonzalezsolveyraestefania sorptionisothermsofwaterinnanoporesrelationshipbetweenhydropohobicityadsorptionpressureandhysteresis AT molinerovaleriapaula sorptionisothermsofwaterinnanoporesrelationshipbetweenhydropohobicityadsorptionpressureandhysteresis |
| _version_ |
1768543393950990336 |