Influence of different confining matrices on negative pressure in liquid n-heptane investigated using positronium bubbles as a probe

Zaleski, R.; Kierys, Agnieszka; Pietrow, M.; Zgardzińska, B.; Blazewicz, A

doi:10.1016/j.jcis.2019.09.111

Cited by 6 publications

(6 citation statements)

References 51 publications

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“…The o-Ps lifetime in water confined in the pores of SBA-3 (2.15(1) ns) is longer than that in bulk water (1.87(4) ns) (Supporting Information, Appendix 5). However, the opposite behavior was observed for n-heptane confined in the same matrix, 42 where the lifetime in the confined liquid was smaller than that in the bulk. It was attributed to the reduced mobility of liquid molecules due to their interaction with pore walls.…”

Section: ■ Results and Discussionmentioning

confidence: 91%

“…This value is slightly smaller than the experimental one, but there is no certainty that the surface tension is identical at p / p 0 = 1 and 0.3. Moreover, the negative pressure calculated with the bubble model for n -heptane confined in the pores of SBA-3 suggests that the Young–Laplace law underestimates the negative pressure (in absolute) by ca. 20% in such small pores at p / p 0 = 0.3.…”

Section: Results and Discussionmentioning

confidence: 95%

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Unraveling the Phase Behavior of Water Confined in Nanochannels through Positron Annihilation

et al. 2022

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Water confined in cylindrical pores of silica with a diameter of 2 nm was studied by positron annihilation lifetime spectroscopy. Instead of freezing at 273 K, the glass-like transition through the viscous state to the solid phase was observed in the wide temperature range of 225–188 K. Reducing the vapor pressure over confined water allowed us to obtain the negative pressure p n = −164 MPa in liquid water, and the phase transition temperature range changed to 234–189 K. The temperature dependence of the ortho-positronium (o-Ps) lifetime in water under p n became consistent with the surface tension as in most liquids, as opposed to the anomalous temperature dependence in water under the saturated vapor pressure. This indicates a reduction in the number of hydrogen bonds in confined water under p n. On this basis, to explain the anomalous temperature dependence, we propose a hypothesis of a partial energy transfer to distant water molecules via the OH-stretching modes instead of repelling the molecules surrounding o-Ps. Our results indicate that thermally generated defects in the confined ice are accompanied by permanent defects, which predominate in the ice formed under p n. Both types of defects have the same volume of 70 Å3, which is much greater than in hexagonal ice I h. We conjecture that the defects are larger due to the influence of the silanol groups on the structure of solid water. These observations imply that the structure of confined ice differs significantly from that of bulk ice and the vapor pressure influences its formation.

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Section: ■ Results and Discussionmentioning

confidence: 91%

Section: Results and Discussionmentioning

confidence: 95%

Unraveling the Phase Behavior of Water Confined in Nanochannels through Positron Annihilation

et al. 2022

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“…Notably, the τ Ps at 100% RH and room temperature (1.5 ns) is obviously shorter than that of bulk water (1.87 ns). The 1.87 ns lifetime of Ps in bulk water originates from Ps bubble formation in water due to the pressure exerted by Ps on the surrounding liquid causing a repulsion in the liquid molecules . Therefore, the shorter τ Ps at 100% RH can be attributed to a suppressed mobility of water molecules to form liquid water due to their interaction with the skeleton.…”

Section: Resultsmentioning

confidence: 99%

Unravelling the Water Adsorption Mechanism in Hierarchical MOFs: Insights from In Situ Positron Annihilation Lifetime Studies

Attallah,

Bon,

Maity

et al. 2023

ACS Appl. Mater. Interfaces

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Atmospheric water harvesting with metal–organic frameworks (MOFs) is a new technology providing a clean, long-term water supply in arid areas. In-situ positron annihilation lifetime spectroscopy (PALS) is proposed as a valid methodology for the mechanistic understanding of water sorption in MOFs and the selection of prospective candidates for desired applications. DUT-67-Zr and DUT-67-Hf frameworks are used as model systems for method validation because of their hierarchical pore structure, high adsorption capacity, and chemical stability. Both frameworks are characterized using complementary techniques, such as nitrogen (77 K) and water vapor (298 K) physisorption, SEM, and PXRD. DUT-67-Zr and DUT-67-Hf are investigated by PALS upon exposure to humidity for the first time, demonstrating the stepwise pore filling mechanism by water molecules for both MOFs. In addition to exploring the potential of PALS as a tool for probing MOFs during in situ water loading, this work offers perspectives on the design and use of MOFs for water harvesting.

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“…Accurate calculation of these require consideration of several factors described in [27][28][29][30][31]. Here we test the consistency of Young-Laplace equation when using MD calculated surface tension and pressure drop, while the ROC is determined using the density cutoff and energy-based methods.…”

Section: Potential Energy Kinetic Energy Densitymentioning

confidence: 99%

An Energy-Based Interface Detection Method for Phase Change Processes in Nanoconfinements

Ozsipahi,

Akkus,

Nguyen

et al. 2021

Preprint

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An energy-based liquid-vapor interface detection method is presented using molecular dynamics (MD) simulations of liquid menisci confined between two parallel plates under equilibrium and evaporation/condensation conditions. This method defines the liquidvapor interface at the location where the kinetic energy of the molecules first exceeds the total potential energy imposed by all neighboring (liquid, vapor, and solid) atoms.This definition naturally adapts to the location of the menisci relative to the walls and can properly model the behavior of the liquid adsorbed layers. Unlike the density cutoff methods frequently used in the literature that suffer from density layering effects, this new method gives smooth and continuous liquid-vapor interfaces in nanoconfinements.Surface tension values calculated from the equilibrium MD simulations match the Young-Laplace equation better when using the radius of curvatures calculated from this method.

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Influence of different confining matrices on negative pressure in liquid n-heptane investigated using positronium bubbles as a probe

Cited by 6 publications

References 51 publications

Unraveling the Phase Behavior of Water Confined in Nanochannels through Positron Annihilation

Unraveling the Phase Behavior of Water Confined in Nanochannels through Positron Annihilation

Unravelling the Water Adsorption Mechanism in Hierarchical MOFs: Insights from In Situ Positron Annihilation Lifetime Studies

An Energy-Based Interface Detection Method for Phase Change Processes in Nanoconfinements

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