Phase properties and wetting transitions of simple gases on graphite─characteristic temperatures of monolayer adsorbate

Computer simulations were performed to study the characteristic transition temperatures of the adsorbate monolayer transitions on graphite and to determine the layering temperatures for higher layers at temperatures less than the bulk triple point temperature. Two models for graphite were studied to...

Full description

Bibliographic Details
Main Authors: Loi, Quang K., Tan, Johnathan Shiliang, Do, D. D., Nicholson, D.
Other Authors: School of Chemical and Biomedical Engineering
Format: Journal Article
Language:English
Published: 2022
Subjects:
Online Access:https://hdl.handle.net/10356/163925
_version_ 1811686918672351232
author Loi, Quang K.
Tan, Johnathan Shiliang
Do, D. D.
Nicholson, D.
author2 School of Chemical and Biomedical Engineering
author_facet School of Chemical and Biomedical Engineering
Loi, Quang K.
Tan, Johnathan Shiliang
Do, D. D.
Nicholson, D.
author_sort Loi, Quang K.
collection NTU
description Computer simulations were performed to study the characteristic transition temperatures of the adsorbate monolayer transitions on graphite and to determine the layering temperatures for higher layers at temperatures less than the bulk triple point temperature. Two models for graphite were studied to examine the effects of finite size of the graphene layer on the evolution of the characteristics of the monolayer, its boundary with the gas phase, and the resulting isotherm and isosteric heat versus loading. Both models give good agreement with experiment for the 2D-critical point and the 2D-triple point, but the finite model is more successful in representing the experimental isotherm and isosteric heat. Radial density distribution for the monolayer supports this, and it illustrates the manner in which the monolayer is compressed with loading, by mass transfer of molecules from the gas phase through the 1D-boundary of the 2D monolayer adsorbate. As the adsorbed phase grows beyond the monolayer, the structure of the thick adsorbed film was shown to lie between the crystalline structure and the dense supercooled liquid, as reflected in partial wetting, defined as finite loading of the adsorbed film at the bulk sublimation pressure.
first_indexed 2024-10-01T05:08:03Z
format Journal Article
id ntu-10356/163925
institution Nanyang Technological University
language English
last_indexed 2024-10-01T05:08:03Z
publishDate 2022
record_format dspace
spelling ntu-10356/1639252022-12-22T03:26:39Z Phase properties and wetting transitions of simple gases on graphite─characteristic temperatures of monolayer adsorbate Loi, Quang K. Tan, Johnathan Shiliang Do, D. D. Nicholson, D. School of Chemical and Biomedical Engineering Engineering::Chemical engineering Kinetic Monte-Carlo Vapor-Liquid-Equilibria Computer simulations were performed to study the characteristic transition temperatures of the adsorbate monolayer transitions on graphite and to determine the layering temperatures for higher layers at temperatures less than the bulk triple point temperature. Two models for graphite were studied to examine the effects of finite size of the graphene layer on the evolution of the characteristics of the monolayer, its boundary with the gas phase, and the resulting isotherm and isosteric heat versus loading. Both models give good agreement with experiment for the 2D-critical point and the 2D-triple point, but the finite model is more successful in representing the experimental isotherm and isosteric heat. Radial density distribution for the monolayer supports this, and it illustrates the manner in which the monolayer is compressed with loading, by mass transfer of molecules from the gas phase through the 1D-boundary of the 2D monolayer adsorbate. As the adsorbed phase grows beyond the monolayer, the structure of the thick adsorbed film was shown to lie between the crystalline structure and the dense supercooled liquid, as reflected in partial wetting, defined as finite loading of the adsorbed film at the bulk sublimation pressure. This work is supported by the Australian Research Council (DP160103540). 2022-12-22T03:26:39Z 2022-12-22T03:26:39Z 2022 Journal Article Loi, Q. K., Tan, J. S., Do, D. D. & Nicholson, D. (2022). Phase properties and wetting transitions of simple gases on graphite─characteristic temperatures of monolayer adsorbate. Journal of Chemical and Engineering Data, 67(7), 1687-1698. https://dx.doi.org/10.1021/acs.jced.1c00911 0021-9568 https://hdl.handle.net/10356/163925 10.1021/acs.jced.1c00911 2-s2.0-85127925592 7 67 1687 1698 en Journal of Chemical and Engineering Data © 2022 American Chemical Society. All rights reserved.
spellingShingle Engineering::Chemical engineering
Kinetic Monte-Carlo
Vapor-Liquid-Equilibria
Loi, Quang K.
Tan, Johnathan Shiliang
Do, D. D.
Nicholson, D.
Phase properties and wetting transitions of simple gases on graphite─characteristic temperatures of monolayer adsorbate
title Phase properties and wetting transitions of simple gases on graphite─characteristic temperatures of monolayer adsorbate
title_full Phase properties and wetting transitions of simple gases on graphite─characteristic temperatures of monolayer adsorbate
title_fullStr Phase properties and wetting transitions of simple gases on graphite─characteristic temperatures of monolayer adsorbate
title_full_unstemmed Phase properties and wetting transitions of simple gases on graphite─characteristic temperatures of monolayer adsorbate
title_short Phase properties and wetting transitions of simple gases on graphite─characteristic temperatures of monolayer adsorbate
title_sort phase properties and wetting transitions of simple gases on graphite─characteristic temperatures of monolayer adsorbate
topic Engineering::Chemical engineering
Kinetic Monte-Carlo
Vapor-Liquid-Equilibria
url https://hdl.handle.net/10356/163925
work_keys_str_mv AT loiquangk phasepropertiesandwettingtransitionsofsimplegasesongraphitecharacteristictemperaturesofmonolayeradsorbate
AT tanjohnathanshiliang phasepropertiesandwettingtransitionsofsimplegasesongraphitecharacteristictemperaturesofmonolayeradsorbate
AT dodd phasepropertiesandwettingtransitionsofsimplegasesongraphitecharacteristictemperaturesofmonolayeradsorbate
AT nicholsond phasepropertiesandwettingtransitionsofsimplegasesongraphitecharacteristictemperaturesofmonolayeradsorbate