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Malfait B, Jani A, Morineau D. Confining deep eutectic solvents in nanopores: Insight into thermodynamics and chemical activity. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118488] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Malfait B, Pouessel A, Jani A, Morineau D. Extension and Limits of Cryoscopy for Nanoconfined Solutions. J Phys Chem Lett 2020; 11:5763-5769. [PMID: 32590897 DOI: 10.1021/acs.jpclett.0c01564] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
This work investigates the phase behavior of aqueous solutions of glycerol confined in MCM-41 and SBA-15 nanoporous matrixes by calorimetry. Limitations due to overfilling and eutectic freezing are prevented by the absence of an external liquid reservoir and by the glass-forming property of glycerol. Consequently, the stability of nanoconfined ice in equilibrium with aqueous solutions is studied over a wide range of compositions. In confinement, a large temperature depression of the liquidus line is observed. A thermodynamic model accounting simultaneously for the cryoscopic and the Gibbs-Thomson effects gives a consistent view of the phase diagram for large pores (Rp = 4.15 nm). For smaller pores (Rp = 1.8 nm), it reveals that the water activity strongly deviates from the bulk solution with the same composition, indicating the possible role of concentration heterogeneities in determining the onset of ice freezing in strongly nanoconfined solutions.
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Affiliation(s)
- Benjamin Malfait
- Institute of Physics of Rennes, CNRS-University of Rennes 1, UMR 6251, F-35042 Rennes, France
| | - Alban Pouessel
- Institute of Physics of Rennes, CNRS-University of Rennes 1, UMR 6251, F-35042 Rennes, France
| | - Aîcha Jani
- Institute of Physics of Rennes, CNRS-University of Rennes 1, UMR 6251, F-35042 Rennes, France
| | - Denis Morineau
- Institute of Physics of Rennes, CNRS-University of Rennes 1, UMR 6251, F-35042 Rennes, France
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Mhanna R, Catrou P, Dutta S, Lefort R, Essafri I, Ghoufi A, Muthmann M, Zamponi M, Frick B, Morineau D. Dynamic Heterogeneities in Liquid Mixtures Confined in Nanopores. J Phys Chem B 2020; 124:3152-3162. [DOI: 10.1021/acs.jpcb.0c01035] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ramona Mhanna
- Institute of Physics of Rennes, CNRS−University of Rennes 1, UMR 6251, F-35042 Rennes, France
- Institut Laue-Langevin, 71 avenue des Martyrs, F-38000 Grenoble, France
| | - Pierre Catrou
- Institute of Physics of Rennes, CNRS−University of Rennes 1, UMR 6251, F-35042 Rennes, France
| | - Sujeet Dutta
- Institute of Physics of Rennes, CNRS−University of Rennes 1, UMR 6251, F-35042 Rennes, France
| | - Ronan Lefort
- Institute of Physics of Rennes, CNRS−University of Rennes 1, UMR 6251, F-35042 Rennes, France
| | - Ilham Essafri
- Institute of Physics of Rennes, CNRS−University of Rennes 1, UMR 6251, F-35042 Rennes, France
| | - Aziz Ghoufi
- Institute of Physics of Rennes, CNRS−University of Rennes 1, UMR 6251, F-35042 Rennes, France
| | - Matthias Muthmann
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ Lichtenbergstrasse 1, 85748 Garching, Germany
| | - Michaela Zamponi
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ Lichtenbergstrasse 1, 85748 Garching, Germany
| | - Bernhard Frick
- Institut Laue-Langevin, 71 avenue des Martyrs, F-38000 Grenoble, France
| | - Denis Morineau
- Institute of Physics of Rennes, CNRS−University of Rennes 1, UMR 6251, F-35042 Rennes, France
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Dutta S, Srikantamurthy S, Mukherjee PK, Krishna Prasad S. Nanometer Confinement-Driven Promotion and Stabilization of a Hexatic Phase Intervening between Ordered Rotator Phases. J Phys Chem B 2018; 122:10953-10963. [PMID: 30422650 DOI: 10.1021/acs.jpcb.8b09017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bulk phase binary mixture of two rotator phase forming alkanes, n-tricosane (C23H48) and n-octacosane (C28H58), has been previously studied. C23H48 exists in the RII and RI phases, whereas C28H58 exists in the RIII and RIV phases. Over a certain range of composition, this binary mixture was found to exist in RII, RI and an intervening mesophase was reported to be the hexatic phase, wherein the long-range two-dimensional in-plane hexagonal lattice order of the RII is lost and what remains is molecules present in hexagonal geometry without long-range positional correlation between individual hexagons. Upon confinement in cylindrical anodized alumina pores 200 nm wide, on the one hand, the temperature range of the hexatic phase was found to extend, and on the other hand, it underwent increased molecular ordering compared to the hexatic phase in bulk, exhibiting two counter-reacting behaviors in confinement. We provide here a temperature-dependent X-ray diffraction study and a theoretical approach combining the Landau and Flory-Huggins theories to, first, understand the underlying mechanism leading to emergence of the hexatic phase and then to explain the effect of confinement on it in the light of finite size and interfacial interaction between the alkanes and alumina pores.
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Affiliation(s)
- Sujeet Dutta
- Centre for Nano and Soft Matter Sciences , Bengaluru 560013 , India
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Dutta S, Prasad SK. Confinement-driven radical change in a sequence of rotator phases: a study on n-octacosane. Phys Chem Chem Phys 2018; 20:24345-24352. [PMID: 30215085 DOI: 10.1039/c8cp03603a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Rotator-phase forming n-alkanes have been studied extensively in both their bulk state and in nanoconfinement. While some alkanes maintain their bulk-state rotator phases in nanoconfinement albeit with increased disorder, there are others exhibiting new rotator phases upon confinement. We present here a temperature dependent X-ray diffraction (XRD) and differential scanning calorimetric (DSC) study on n-octacosane (C28H58), which almost completely loses its bulk state RIV phase and undergoes complete disappearance of its RIII phase. In their place, when confined in cylindrical anodized alumina nanopores, a phase highly resembling the hexatic mesophase is formed at a higher temperature and the RI rotator phase at a lower temperature. The effects of finite size, interfacial interactions with the host matrix and alkyl chain flexibility are used to provide an explanation for such unexpected behaviour.
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Affiliation(s)
- Sujeet Dutta
- Centre for Nano and Soft Matter Sciences, Bengaluru, Karnataka, India.
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Abstract
Empty spaces are abhorred by nature, which immediately rushes in to fill the void. Humans have learnt pretty well how to make ordered empty nanocontainers, and to get useful products out of them. When such an order is imparted to molecules, new properties may appear, often yielding advanced applications. This review illustrates how the organized void space inherently present in various materials: zeolites, clathrates, mesoporous silica/organosilica, and metal organic frameworks (MOF), for example, can be exploited to create confined, organized, and self-assembled supramolecular structures of low dimensionality. Features of the confining matrices relevant to organization are presented with special focus on molecular-level aspects. Selected examples of confined supramolecular assemblies - from small molecules to quantum dots or luminescent species - are aimed to show the complexity and potential of this approach. Natural confinement (minerals) and hyperconfinement (high pressure) provide further opportunities to understand and master the atomistic-level interactions governing supramolecular organization under nanospace restrictions.
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Affiliation(s)
- Gloria Tabacchi
- Department of Science and High Technology, University of Insubria, Via Valleggio, 9 I-22100, Como, Italy
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Essafri I, Courtin J, Ghoufi A. Numerical evidence of heterogeneity and nanophases in a binary liquid confined at the nanoscale. MOLECULAR SIMULATION 2018. [DOI: 10.1080/08927022.2018.1444762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- I. Essafri
- Institut de Physique de Rennes, UMR CNRS 6251, Université Rennes 1, Rennes, France
| | - J. Courtin
- Institut de Physique de Rennes, UMR CNRS 6251, Université Rennes 1, Rennes, France
| | - A. Ghoufi
- Institut de Physique de Rennes, UMR CNRS 6251, Université Rennes 1, Rennes, France
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Prado JR, Vyazovkin S. Phase separation of triethylamine and water in native and organically modified silica nanopores. J Chem Phys 2017; 147:114508. [PMID: 28938834 DOI: 10.1063/1.5003906] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A mixture of triethylamine and water is a lower critical solution temperature system that demixes (separates into individual phases) on heating. Differential scanning calorimetry has been applied to study the process of demixing in native and organically modified silica nanopores whose size varied from 4 to 30 nm. It has been found that in both types of nanopores, the temperature and enthalpy of demixing decrease significantly with decreasing the pore size. Isoconversional kinetic analysis has been utilized to determine the activation energy and pre-exponential factor of the process. It has been demonstrated that the depression of the transition temperature upon nanoconfinement is associated with acceleration of the process due to lowering of the activation energy. Nanoconfinement has also been found to lower the pre-exponential factor of the process that has been linked to a decrease in the molecular mobility.
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Affiliation(s)
- J Rachel Prado
- Department of Chemistry, University of Alabama at Birmingham, 901 S. 14th Street, Birmingham, Alabama 35294, USA
| | - Sergey Vyazovkin
- Department of Chemistry, University of Alabama at Birmingham, 901 S. 14th Street, Birmingham, Alabama 35294, USA
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