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Castaño Plaza O, Loi QK, Herrera Diaz LF, Do DD, Nicholson D. Effects of a Free Adsorbate Boundary on the Description of an Argon Adsorbed Film on Graphite below the Bulk Triple Point. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:7456-7468. [PMID: 37192409 DOI: 10.1021/acs.langmuir.3c00722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Monte Carlo simulations have been carried out to study argon adsorption on graphite at temperatures below the bulk triple point temperature, Ttr(bulk) = 83.8 K. Two models for graphite have been used to investigate the effects of an adsorbate patch with a free boundary on the layering temperatures, the two-dimensional (2D)-triple point and the 2D-critical point for the three adsorbate layers on the surface. The first model (S-model) has a planar surface of infinite extent in the two directions parallel to the surface, and the second is a finite (2D-patch model). Although simulations using both models describe the characteristic temperatures, only the 2D-patch model can represent the experimental isotherms accurately, and the condensation pressures at which first-order transitions occur, while simulations with the S-model yield many unphysical substeps that are not observed experimentally in the first layer adsorbate, which leads to a poor description of higher adsorbate layers. These results support the interpretation that boundary growth of an adsorbate patch is the mechanism for argon adsorption at temperatures below the bulk triple point temperature. Combining the results derived from this simulation study for temperatures below the bulk triple point temperature, with results reported in the literature for temperatures above Ttr(bulk) and experimental data, we have constructed a generic pattern for the adsorption isotherms of simple gases on graphite at temperatures ranging from well below the bulk triple point temperature up to the bulk critical temperature, a comprehensive description not widely recognized in the literature.
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Affiliation(s)
- Octavio Castaño Plaza
- Energy and Resources Institute, Charles Darwin University, Darwin, NT 0909, Australia
| | - Quang K Loi
- Centre for Theoretical and Computer Molecular Science, Australian Institute for the Bioengineering and Nanotechnology, St Lucia, QLD 4072, Australia
| | - Luis F Herrera Diaz
- Energy and Resources Institute, Charles Darwin University, Darwin, NT 0909, Australia
| | - D D Do
- School of Chemical Engineering, University of Queensland, St Lucia, QLD 4072, Australia
| | - D Nicholson
- School of Chemical Engineering, University of Queensland, St Lucia, QLD 4072, Australia
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Dilokekunakul W, Chaemchuen S, Klomkliang N. Molecular Insights into the Effect of Temperature and Functional Groups on the Nonwetting, Prewetting, Partial Wetting, and Complete Wetting Transitions of Ethanol on Graphite. Ind Eng Chem Res 2021. [DOI: 10.1021/acs.iecr.1c01952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Waralee Dilokekunakul
- School of Chemical Engineering, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - Somboon Chaemchuen
- Laboratory of Organometallics, Catalysis and Ordered Materials, State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, P. R. China
| | - Nikom Klomkliang
- School of Chemical Engineering, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
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Tan SJ, Liu L, Chew JW. Competitive and Synergistic Adsorption of Mixtures of Polar and Nonpolar Gases in Carbonaceous Nanopores. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:6754-6764. [PMID: 34038636 DOI: 10.1021/acs.langmuir.1c00822] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Most adsorption applications involve mixtures, yet accurate predictions of the adsorption of mixtures remain challenging, in part due to the inability to account for the interplay between adsorbate-adsorbate and adsorbate-adsorbent interactions. This study involves a comprehensive Monte Carlo simulation of the adsorption of two groups of mixtures (namely, supercritical and subcritical ones) in carbon nanopores and quantifies Henry's constants, isotherms, energetics, and density distributions in the pores. When interadsorbate interactions are negligible (e.g., in supercritical mixtures such as mixtures of nonpolar gases), adsorbates behave like ideal gases and the adsorption isotherm can be predicted with the ideal adsorbed solution theory (IAST). However, when interadsorbate interactions become significant, IAST fails. This study reveals that (1) in mixtures of polar and nonpolar gases, the stronger intermolecular interaction for the polar constituent leads to synergistic adsorption that causes the nonpolar adsorbate to desorb and (2) for mixtures of polar gases, such as ethanol and water, the adsorbate-adsorbate interactions are so dominant that the unfavorable adsorbate-adsorbent interactions are overcome, such that water adsorbs onto the hydrophobic adsorbent. The competitive and synergistic interactions highlighted here are expected to be valuable in enhancing gas separations.
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Affiliation(s)
- Shiliang Johnathan Tan
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore
| | - Lumeng Liu
- School of Civil Engineering, Chongqing University, Chongqing 400045, China
| | - Jia Wei Chew
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore
- Singapore Membrane Technology Centre, Nanyang Environmental and Water Research Institute, Nanyang Technological University, Singapore 637141, Singapore
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Evolution of adsorption isotherm and isosteric heat from sub-triple to super-critical points. ADSORPTION 2021. [DOI: 10.1007/s10450-020-00294-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Liu X, Fan C, Do D, Pareek V, Yang P. A temperature-dependent potential model for mercury in the description of vapour-liquid equilibrium & adsorption in activated carbon. Chem Eng Sci 2020. [DOI: 10.1016/j.ces.2019.115453] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Tan SJ, Prasetyo L, Do DD, Nicholson D. Interplay between Wetting and Filling of Argon Adsorption in Slit Pores with Different Surface Energies Transition from Filling in Micropores to Capillary Condensation in Mesopores. Ind Eng Chem Res 2019. [DOI: 10.1021/acs.iecr.9b03439] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Shiliang Johnathan Tan
- School of Chemical Engineering, University of Queensland, St. Lucia, Qld 4072, Australia
| | - Luisa Prasetyo
- School of Chemical Engineering, University of Queensland, St. Lucia, Qld 4072, Australia
| | - D. D. Do
- School of Chemical Engineering, University of Queensland, St. Lucia, Qld 4072, Australia
| | - D. Nicholson
- School of Chemical Engineering, University of Queensland, St. Lucia, Qld 4072, Australia
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Jiménez-Serratos G, Cárdenas H, Müller EA. Extension of the effective solid-fluid Steele potential for Mie force fields. Mol Phys 2019. [DOI: 10.1080/00268976.2019.1669836] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
| | - Harry Cárdenas
- Department of Chemical Engineering, Imperial College London, London, UK
| | - Erich A. Müller
- Department of Chemical Engineering, Imperial College London, London, UK
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Tan SJ, Loi QK, Do DD, Nicholson D. On the canonical isotherms for bulk fluid, surface adsorption and adsorption in pores: A common thread. J Colloid Interface Sci 2019; 548:25-36. [PMID: 30978593 DOI: 10.1016/j.jcis.2019.04.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 03/06/2019] [Accepted: 04/05/2019] [Indexed: 11/18/2022]
Abstract
Kinetic Monte Carlo simulated isotherms calculated in the canonical ensemble, at temperatures below the critical temperature, for bulk fluid, surface adsorption and adsorption in a confined space, show a van der Waals (vdW) loop with a vertical phase transition between the rarefied and dense spinodal points at the co-existence chemical potential, µco. Microscopic examination of the state points on this loop reveals features that are common to these systems. At state points with chemical potentials greater than μco the microscopic configurations show clusters, which coalesce to form two co-existing phases along the vertical section of the loop (the coexistence line). As more molecules are added, the dense region expands at the expense of the rarefied region, to the point where the rarefied region becomes spherical (cylindrical for 2D-systems) with a curvature greater than that of the coexisting phases. This results in a decrease of chemical potential from µco to the liquid spinodal point where the rarefied region disappears. With a further increase in loading, the chemical potential and the density increase. The existence of a vdW loop is the microscopic reason for the hysteresis observed in the grand canonical isotherm, where the adsorption and desorption boundaries of the hysteresis loop are first-order transitions, enclosing the vertical section of the vdW loop of the canonical isotherm. However, a first-order transition is rarely observed in experiments where transitions are usually steep, but not vertical. From our extensive simulations, we provide two possible reasons: (1) the finite extent of the system and (2) the existence of high energy sites that localize the clusters. In the first case, the desorption branch, and in the second case the adsorption branch, either comes close to, or collapses onto the coexistence line. When both occur, the hysteresis loop disappears and the isotherm is reversible, as often observed experimentally.
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Affiliation(s)
- Shiliang Johnathan Tan
- School of Chemical Engineering, University of Queensland, St. Lucia, Qld 4072, Australia
| | - Quang K Loi
- School of Chemical Engineering, University of Queensland, St. Lucia, Qld 4072, Australia
| | - D D Do
- School of Chemical Engineering, University of Queensland, St. Lucia, Qld 4072, Australia.
| | - D Nicholson
- School of Chemical Engineering, University of Queensland, St. Lucia, Qld 4072, Australia
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Loi QK, Prasetyo L, Tan S, Do DD, Nicholson D. Nonwetting/Prewetting/Wetting Transition of Ammonia on Graphite. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:641-652. [PMID: 30575395 DOI: 10.1021/acs.langmuir.8b03634] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Simulations of ammonia adsorption on graphite were carried out over a range of temperatures to investigate the transition from nonwetting to wetting. The process is governed by a subtle interplay between the various interactions in the system and the temperature. At temperatures below the bulk triple point, the system is nonwetting; above the triple point, we observed continuous wetting, preceded by a prewetting region in which the so-called thin-to-thick film transition occurs. This system serves as an excellent example of wetting/nonwetting behavior in an associating fluid as a function of temperature because the heat of sublimation (or condensation) is greater than the isosteric heat of adsorption at zero loading. The nonwetting-to-wetting transition (NW/W) is also strongly affected by the adsorbate-adsorbate interaction, which becomes important when this contribution to the isosteric heat is of a similar magnitude to the heat of condensation. An appropriate indicator of a NW/W transition at a given loading is therefore the difference between the isosteric heat and the heat of sublimation (or condensation). Our simulation results show the "thin-to-thick" film transition in the temperature range between 195 and 240 K, which has not been previously explained. Above 240 K, continuous wetting occurs. This study provides a basis for a better understanding of adsorption in a range of systems because ammonia is an intermediate between simple molecules, such as argon, and strongly associating fluids, such as water.
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Affiliation(s)
- Quang K Loi
- School of Chemical Engineering , University of Queensland , St. Lucia , QLD 4072 , Australia
| | - Luisa Prasetyo
- School of Chemical Engineering , University of Queensland , St. Lucia , QLD 4072 , Australia
| | - Shiliang Tan
- School of Chemical Engineering , University of Queensland , St. Lucia , QLD 4072 , Australia
| | - D D Do
- School of Chemical Engineering , University of Queensland , St. Lucia , QLD 4072 , Australia
| | - D Nicholson
- School of Chemical Engineering , University of Queensland , St. Lucia , QLD 4072 , Australia
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Prasetyo L, Horikawa T, Takashima N, Do DD, Nicholson D. On the transition from partial wetting to complete wetting of methanol on graphite. Phys Chem Chem Phys 2019; 21:26219-26231. [DOI: 10.1039/c9cp05118j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Excellent agreement with experiment for methanol adsorption on graphitized carbon black at low temperatures by Monte Carlo simulation. Incomplete wetting and complete wetting are observed at a range of temperatures above the triple point.
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Affiliation(s)
- Luisa Prasetyo
- School of Chemical Engineering
- University of Queensland
- St. Lucia
- Australia
| | - Toshihide Horikawa
- Graduate School of Technology
- Industrial and Social Sciences
- University of Tokushima
- Tokushima 770-8506
- Japan
| | - Naoki Takashima
- Graduate School of Technology
- Industrial and Social Sciences
- University of Tokushima
- Tokushima 770-8506
- Japan
| | - D. D. Do
- School of Chemical Engineering
- University of Queensland
- St. Lucia
- Australia
| | - D. Nicholson
- School of Chemical Engineering
- University of Queensland
- St. Lucia
- Australia
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