Molecular dynamics simulation and thermodynamic model of triple point of Lennard-Jones fluid in cylindrical nanopores

Kanda, Hideki; Hiramatsu, Takeshi; Diono, Wahyu; Goto, Motonobu

doi:10.1016/j.ces.2021.116829

Cited by 5 publications

(6 citation statements)

References 34 publications

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“…The crossing point is where the capillary melting occurs under saturated bulk vapor. These observations are consistent with the trend of the pore solid–liquid phase transition curve predicted by molecular simulations and the solid–liquid model introduced by Kanda et al , However, our test experiment at 72 bar failed to detect potential capillary melting before the bulk evaporation peak upon heating, which is expected to happen if we have the crossover. This may be due to the fact that the small capillary-melting peak is obscured by the curved baseline in the vicinity of the bulk critical point, where the specific heat of CO 2 changes rapidly.…”

Section: Resultssupporting

confidence: 93%

“…For the LJ fluid in cylindrical nanopores, the pore triple-point temperatures were lower than those of the bulk triple point, whereas the pore triple-point pressures were much lower (approximately an order of magnitude lower) than those of the bulk triple point. In addition, they also observed hysteresis of the pore triple point of the LJ fluid confined in cylindrical nanopores, the hysteresis width of which in the heating operation was found to be approximately 2–3 K for these three pores (i.e., 7.5σ ff , 9.5σ ff , and 11.5σ ff ) . However, their simulation and modeling results have not been verified against experimental data.…”

Section: Introductionmentioning

confidence: 94%

“…In addition, they also observed hysteresis of the pore triple point of the LJ fluid confined in cylindrical nanopores, the hysteresis width of which in the heating operation was found to be approximately 2−3 K for these three pores (i.e., 7.5σ ff , 9.5σ ff , and 11.5σ ff ). 36 However, their simulation and modeling results have not been verified against experimental data.…”

Section: ■ Introductionmentioning

confidence: 99%

“…On the molecular simulation side, Kanda et al examined the pore triple point of a Lennard-Jones (LJ) fluid in slit-shaped nanopores with pore widths of 5.5σ ff , 7.5σ ff , and 10.0σ ff and cylindrical nanopores with pore diameters of 7.5σ ff , 9.5σ ff , and 11.5σ ff using molecular dynamics simulations, where σ ff is the LJ molecular diameter. , The pore wall was modeled on carbon/graphite, which was a structureless, smooth wall. For the LJ fluid in slit-shaped nanopores, they concluded that the shift of the pore triple-point temperature from the bulk was not certain; i.e., it could be higher or lower than the bulk triple-point temperature depending on the pore size.…”

Section: Introductionmentioning

confidence: 99%

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Experimental Study on Phase Transitions of Carbon Dioxide Confined in Nanopores: Evaporation, Melting, Sublimation, and Triple Point

Yang,

Dejam,

Tan

et al. 2023

Langmuir

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Capillary phase transitions (evaporation, melting, and sublimation) and the pore triple point of CO 2 confined in MCM-41 mesoporous media with a pore diameter of 3.5 nm have been studied by using an isochoric heating procedure in a highpressure low-temperature differential scanning calorimeter over a pressure range of 0.5−40.5 bar. The procedure is validated by the agreement between the measured conditions of bulk evaporation/ sublimation and literature data. The main finding in this work is that the solid-to-fluid phase transitions of CO 2 in MCM-41 shift to temperatures higher than those of the corresponding bulk phase transitions. It is also found that the formation of a solid phase of CO 2 in MCM-41 does not require the presence of a liquid or solid in the bulk. The capillary-melting and capillary-evaporation curves approach each other as temperature decreases until they meet at the pore triple point. The effect of pressure on capillary melting temperature is significant at pressures close to the pore triple point. Furthermore, the capillary-melting curve approaches the bulk saturated vapor-pressure curve as temperature increases, thus hinting an agreement with the prediction by molecular dynamics simulation in the literature that the curves eventually intersect each other at a high temperature and pressure. Based on the measured capillary phase transitions, the pore triple-point temperature and pressure of nanoconfined CO 2 are bracketed and found to be much lower than those of the bulk triple point.

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Section: Resultssupporting

confidence: 93%

Section: Introductionmentioning

confidence: 94%

Section: ■ Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Experimental Study on Phase Transitions of Carbon Dioxide Confined in Nanopores: Evaporation, Melting, Sublimation, and Triple Point

Yang,

Dejam,

Tan

et al. 2023

Langmuir

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show abstract

“…This study adopts the all-atom force field 27 for calculation, employing the SPC/E water molecule model. 28 Models featuring oxygen-containing and vacuum bubbles with varying radii and quantities are established. Utilizing the momentum mirror method 29 and the C language at room temperature, this study focuses on parameters such as the maximum local density, released pressure, and water molecule temperature, summarizing the impacts and mechanisms concerning the presence of gas in bubbles, the bubble size, and the quantity on collapse.…”

Section: ■ Introductionmentioning

confidence: 99%

Effect of Shock-Wave-Mediated Collapse on Nanobubble Characteristics

Xu,

Zhao,

Wang

et al. 2023

Langmuir

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To enhance the comprehension of the cavitation mechanism and explore its practical use in industrial production, this study developed models involving oxygen, varying bubble radii, and bubble quantities. This study uses molecular dynamics simulations coupled with the momentum mirror method to examine the collapse characteristics of bubbles during ultrasonic cavitation. The investigation uncovers patterns in the fluctuation of the maximum local density of water molecules, released pressure, and temperature. The findings demonstrate that, when oxygen-containing bubbles collapse at identical radii, the local density is notably higher and diminishes more rapidly. Moreover, the changes in the shape exhibit greater regularity. During the bubble collapse, a depression forms on the bubble's surface, coinciding with a notable surge in local density around the depression. As bubble radii and quantities increase, so does the local density along with a concurrent rise in the maximum pressure. Intriguingly, the model demonstrates the lowest pressure at Z = 35 Å accompanied by the emergence of a small crescent-shaped region with a reduced density. Throughout the pressure ascension phase, the rate of the maximum pressure change escalates with an increase in the number of bubbles. Conversely, during the pressure descent phase, the rate of the maximum pressure change diminishes with a growing number of bubbles. However, it is important to note that the maximum pressure does not exhibit a direct correlation with the number of bubbles. Ultimately, this study provides valuable technical guidance and a theoretical foundation for the integration of ultrasonic cavitation in industrial production processes.

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Thermodynamic model of extraction equilibrium in cylindrical nanopores validated with molecular dynamics simulation

Kanda

Diono

Goto

2022

Chemical Engineering Science

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Molecular dynamics simulation and thermodynamic model of triple point of Lennard-Jones fluid in cylindrical nanopores

Cited by 5 publications

References 34 publications

Experimental Study on Phase Transitions of Carbon Dioxide Confined in Nanopores: Evaporation, Melting, Sublimation, and Triple Point

Experimental Study on Phase Transitions of Carbon Dioxide Confined in Nanopores: Evaporation, Melting, Sublimation, and Triple Point

Effect of Shock-Wave-Mediated Collapse on Nanobubble Characteristics

Thermodynamic model of extraction equilibrium in cylindrical nanopores validated with molecular dynamics simulation

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