Reversible Surface Energy Storage in Molecular-Scale Porous Materials
Forcible wetting of hydrophobic pores represents a viable method for energy storage in the form of interfacial energy. The energy used to fill the pores can be recovered as pressure–volume work upon decompression. For efficient recovery, the expulsion pressure should not be significantly lower than...
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MDPI AG
2024-01-01
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Series: | Molecules |
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Online Access: | https://www.mdpi.com/1420-3049/29/3/664 |
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author | Dusan Bratko |
author_facet | Dusan Bratko |
author_sort | Dusan Bratko |
collection | DOAJ |
description | Forcible wetting of hydrophobic pores represents a viable method for energy storage in the form of interfacial energy. The energy used to fill the pores can be recovered as pressure–volume work upon decompression. For efficient recovery, the expulsion pressure should not be significantly lower than the pressure required for infiltration. Hysteresis of the wetting/drying cycle associated with the kinetic barrier to liquid expulsion results in energy dissipation and reduced storage efficiency. In the present work, we use open ensemble (Grand Canonical) Monte Carlo simulations to study the improvement of energy recovery with decreasing diameters of planar pores. Near-complete reversibility is achieved at pore widths barely accommodating a monolayer of the liquid, thus minimizing the area of the liquid/gas interface during the cavitation process. At the same time, these conditions lead to a steep increase in the infiltration pressure required to overcome steric wall/water repulsion in a tight confinement and a considerable reduction in the translational entropy of confined molecules. In principle, similar effects can be expected when increasing the size of the liquid particles without altering the absorbent porosity. While the latter approach is easier to follow in laboratory work, we discuss the advantages of reducing the pore diameter, which reduces the cycling hysteresis while <i>simultaneously</i> improving the stored-energy density in the material. |
first_indexed | 2024-03-08T03:51:36Z |
format | Article |
id | doaj.art-439a5408a2194569816928806ba0954d |
institution | Directory Open Access Journal |
issn | 1420-3049 |
language | English |
last_indexed | 2024-03-08T03:51:36Z |
publishDate | 2024-01-01 |
publisher | MDPI AG |
record_format | Article |
series | Molecules |
spelling | doaj.art-439a5408a2194569816928806ba0954d2024-02-09T15:19:01ZengMDPI AGMolecules1420-30492024-01-0129366410.3390/molecules29030664Reversible Surface Energy Storage in Molecular-Scale Porous MaterialsDusan Bratko0Department of Chemistry, Virginia Commonwealth University, Richmond, VA 23221, USAForcible wetting of hydrophobic pores represents a viable method for energy storage in the form of interfacial energy. The energy used to fill the pores can be recovered as pressure–volume work upon decompression. For efficient recovery, the expulsion pressure should not be significantly lower than the pressure required for infiltration. Hysteresis of the wetting/drying cycle associated with the kinetic barrier to liquid expulsion results in energy dissipation and reduced storage efficiency. In the present work, we use open ensemble (Grand Canonical) Monte Carlo simulations to study the improvement of energy recovery with decreasing diameters of planar pores. Near-complete reversibility is achieved at pore widths barely accommodating a monolayer of the liquid, thus minimizing the area of the liquid/gas interface during the cavitation process. At the same time, these conditions lead to a steep increase in the infiltration pressure required to overcome steric wall/water repulsion in a tight confinement and a considerable reduction in the translational entropy of confined molecules. In principle, similar effects can be expected when increasing the size of the liquid particles without altering the absorbent porosity. While the latter approach is easier to follow in laboratory work, we discuss the advantages of reducing the pore diameter, which reduces the cycling hysteresis while <i>simultaneously</i> improving the stored-energy density in the material.https://www.mdpi.com/1420-3049/29/3/664molecular porosityinterfacial energywetting/dewetting hysteresisopen ensemble molecular simulations |
spellingShingle | Dusan Bratko Reversible Surface Energy Storage in Molecular-Scale Porous Materials Molecules molecular porosity interfacial energy wetting/dewetting hysteresis open ensemble molecular simulations |
title | Reversible Surface Energy Storage in Molecular-Scale Porous Materials |
title_full | Reversible Surface Energy Storage in Molecular-Scale Porous Materials |
title_fullStr | Reversible Surface Energy Storage in Molecular-Scale Porous Materials |
title_full_unstemmed | Reversible Surface Energy Storage in Molecular-Scale Porous Materials |
title_short | Reversible Surface Energy Storage in Molecular-Scale Porous Materials |
title_sort | reversible surface energy storage in molecular scale porous materials |
topic | molecular porosity interfacial energy wetting/dewetting hysteresis open ensemble molecular simulations |
url | https://www.mdpi.com/1420-3049/29/3/664 |
work_keys_str_mv | AT dusanbratko reversiblesurfaceenergystorageinmolecularscaleporousmaterials |