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High-temperature and high-pressure NMR investigations of low viscous fluids confined in mesoporous systems. Z PHYS CHEM 2020. [DOI: 10.1515/zpch-2019-1510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
In this contribution, the relaxation and diffusional behaviors of low viscous fluids, water and methanol confined into mesoporous silica and controlled size pore glass were investigated. The engineered porous systems are relevant to geologically important subsurface energy materials. The engineered porous proxies were characterized by Brunauer–Emmett–Teller (BET) surface analyzer, nuclear magnetic resonance (NMR) spectroscopy, and electron microscopy (EM) to determine surface area, pore-wall protonation and morphology of these materials, respectively. The confined behavior of the low viscous fluids was studied by varying pore diameter, fluid-to-solid ratio, temperature, and pressure, and then compared to bulk liquid state. Both relaxation and diffusion behaviors for the confined fluids showed increasing deviation from pure bulk fluids as the fluid-to-solid ratio was decreased, and surface-to-volume ratio (S/V) was varied. Variable pressure deuteron NMR relaxation of confined D2O and confined methanol, deuterated at the hydroxyl or methyl positions, were performed to exploit the sensitivity of the deuteron quadrupole moment to molecular rotation. The methanol results demonstrated greater pressure dependence than those for water only in bulk. The deviations from bulk liquid behavior arise from different reasons such as confinement and the interactions between confined fluid and the nano-pore wall. The results of the present report give insight into the behavior of low viscosity fluid in nano-confined geometries under different state conditions.
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Bonnaud PA, Coasne B, Pellenq RJM. Molecular simulation of water confined in nanoporous silica. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:284110. [PMID: 21399282 DOI: 10.1088/0953-8984/22/28/284110] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This paper reports on a molecular simulation study of the thermodynamics, structure and dynamics of water confined at ambient temperature in hydroxylated silica nanopores of a width H = 10 and 20 Å. The adsorption isotherms for water in these nanopores resemble those observed for experimental samples; the adsorbed amount increases continuously in the multilayer adsorption regime until a jump occurs due to capillary condensation of the fluid within the pore. Strong layering of water in the vicinity of the silica surfaces is observed as marked density oscillations are observed up to 8 Å from the surface in the density profiles for confined water. Our results indicate that water molecules within the first adsorbed layer tend to adopt a H-down orientation with respect to the silica substrate. For all pore sizes and adsorbed amounts, the self-diffusivity of confined water is lower than the bulk, due to the hydrophilic interaction between the water molecules and the hydroxylated silica surface. Our results also suggest that the self-diffusivity of confined water is sensitive to the adsorbed amount.
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Affiliation(s)
- P A Bonnaud
- Centre Interdisciplinaire des Nanosciences de Marseille, CNRS and Aix-Marseille Université, Campus de Luminy, F-13288 Marseille Cedex 9, France
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Alba-Simionesco C, Coasne B, Dosseh G, Dudziak G, Gubbins KE, Radhakrishnan R, Sliwinska-Bartkowiak M. Effects of confinement on freezing and melting. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2006; 18:R15-R68. [PMID: 21697556 DOI: 10.1088/0953-8984/18/6/r01] [Citation(s) in RCA: 337] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We present a review of experimental, theoretical, and molecular simulation studies of confinement effects on freezing and melting. We consider both simple and more complex adsorbates that are confined in various environments (slit or cylindrical pores and also disordered porous materials). The most commonly used molecular simulation, theoretical and experimental methods are first presented. We also provide a brief description of the most widely used porous materials. The current state of knowledge on the effects of confinement on structure and freezing temperature, and the appearance of new surface-driven and confinement-driven phases are then discussed. We also address how confinement affects the glass transition.
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Affiliation(s)
- C Alba-Simionesco
- Laboratoire de Chimie Physique, CNRS-UMR 8000, Bâtiment 349, Université de Paris-Sud, F-91405 Orsay, France
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Vargas-Florencia D, Petrov O, Furó I. Inorganic Salt Hydrates as Cryoporometric Probe Materials to Obtain Pore Size Distribution. J Phys Chem B 2006; 110:3867-70. [PMID: 16509668 DOI: 10.1021/jp055915k] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The depression of the melting temperature of Zn(NO3)2.6H2O was used to obtain the pore size distributions in controlled pore glasses. Measured by 1H NMR, the average value of the temperature depression DeltaT and the known average pore size yield K=DeltaT.d approximately 116 K.nm as the material-dependent factor for Zn(NO3)2.6H2O in the Gibbs-Thompson equation. The melting temperature is close to room temperature. Hence, this salt hydrate and some related other ones are better materials than water (K approximately 50 K.nm) for cryoporometric studies of systems with hydrophilic pores. The data also provide 46 mN/m for the solid-liquid surface tension of this salt hydrate.
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Affiliation(s)
- D Vargas-Florencia
- Division of Physical Chemistry and Industrial NMR Center, Department of Chemistry, Royal Institute of Technology, SE-10044 Stockholm, Sweden
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Petrov O, Furó I. Curvature-dependent metastability of the solid phase and the freezing-melting hysteresis in pores. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2006; 73:011608. [PMID: 16486162 DOI: 10.1103/physreve.73.011608] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2005] [Revised: 09/28/2005] [Indexed: 05/06/2023]
Abstract
We recapitulate and generalize the concept of the freezing-melting hysteresis that attributes this phenomenon to a free-energy barrier between metastable and stable states of pore-filling material. In a phenomenological description, we show that under commonly encountered conditions, this renders the freezing-point depression DeltaTf defined by the surface-to-volume ratio S/V, whereas the melting-point depression DeltaTm, by the mean curvature kappa of the pore surface, with DeltaTm/DeltaTf =2kappa(V/S). Employing 1H NMR cryoporometry, we experimentally demonstrate the linear correlation between DeltaTm and DeltaTf for several liquids with different DeltaTf,m imbibed in controlled pore glasses. The results compare favorably to the morphological properties of the glasses determined by other techniques. Our findings suggest a simple method for analyzing the pore morphology from the observed phase transition temperatures.
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Affiliation(s)
- Oleg Petrov
- Division of Physical Chemistry, Department of Chemistry, Royal Institute of Technology, SE-10044 Stockholm, Sweden
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Telkki VV, Lounila J, Jokisaari J. Behavior of Acetonitrile Confined to Mesoporous Silica Gels As Studied by 129Xe NMR: A Novel Method for Determining the Pore Sizes. J Phys Chem B 2004; 109:757-63. [PMID: 16866438 DOI: 10.1021/jp046788f] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
129Xe NMR spectra of xenon dissolved in acetonitrile confined into three mesoporous silica gels with nominal pore diameters of 40, 60, and 100 A have been measured over the temperature range 170-245 K. The spectra consist of a number of lines, which contain detailed information on the system. The most interesting result is that the chemical shift of a particular signal observed below the melting point of confined acetonitrile is highly sensitive to the pore size, and hence its shape is sensitive to the pore size distribution function. This signal originates from the xenon atoms sited in very small cavities built up inside the pores during the freezing transition. It can be used to determine the size or even the size distribution function of the pores. In addition, the emergence of this signal reveals the phase transition temperature of acetonitrile inside the pores, which can also be used to determine the size of the pores. The difference in the chemical shifts of two other signals, which arise from xenon dissolved in bulk and confined acetonitrile, provides still another novel method for determining the size of the pores.
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Affiliation(s)
- Ville-Veikko Telkki
- Department of Physical Sciences, NMR Research Group, University of Oulu, P.O. Box 3000, FIN-90014, Finland
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Gane PAC, Ridgway CJ, Lehtinen E, Valiullin R, Furó I, Schoelkopf J, Paulapuro H, Daicic J. Comparison of NMR Cryoporometry, Mercury Intrusion Porosimetry, and DSC Thermoporosimetry in Characterizing Pore Size Distributions of Compressed Finely Ground Calcium Carbonate Structures. Ind Eng Chem Res 2004. [DOI: 10.1021/ie049448p] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Patrick A. C. Gane
- Omya Development AG, CH 4665 Oftringen, Switzerland, Helsinki University of Technology, Box 6300, FI-02015 Hut, Finland, KTH Royal Institute of Technology, Teknikringen 30/36, SE-10044 Stockholm, Sweden, and YKI Institute for Surface Chemistry, Box 5607, SE-11486 Stockholm, Sweden
| | - Cathy J. Ridgway
- Omya Development AG, CH 4665 Oftringen, Switzerland, Helsinki University of Technology, Box 6300, FI-02015 Hut, Finland, KTH Royal Institute of Technology, Teknikringen 30/36, SE-10044 Stockholm, Sweden, and YKI Institute for Surface Chemistry, Box 5607, SE-11486 Stockholm, Sweden
| | - Esa Lehtinen
- Omya Development AG, CH 4665 Oftringen, Switzerland, Helsinki University of Technology, Box 6300, FI-02015 Hut, Finland, KTH Royal Institute of Technology, Teknikringen 30/36, SE-10044 Stockholm, Sweden, and YKI Institute for Surface Chemistry, Box 5607, SE-11486 Stockholm, Sweden
| | - Rustem Valiullin
- Omya Development AG, CH 4665 Oftringen, Switzerland, Helsinki University of Technology, Box 6300, FI-02015 Hut, Finland, KTH Royal Institute of Technology, Teknikringen 30/36, SE-10044 Stockholm, Sweden, and YKI Institute for Surface Chemistry, Box 5607, SE-11486 Stockholm, Sweden
| | - Istvan Furó
- Omya Development AG, CH 4665 Oftringen, Switzerland, Helsinki University of Technology, Box 6300, FI-02015 Hut, Finland, KTH Royal Institute of Technology, Teknikringen 30/36, SE-10044 Stockholm, Sweden, and YKI Institute for Surface Chemistry, Box 5607, SE-11486 Stockholm, Sweden
| | - Joachim Schoelkopf
- Omya Development AG, CH 4665 Oftringen, Switzerland, Helsinki University of Technology, Box 6300, FI-02015 Hut, Finland, KTH Royal Institute of Technology, Teknikringen 30/36, SE-10044 Stockholm, Sweden, and YKI Institute for Surface Chemistry, Box 5607, SE-11486 Stockholm, Sweden
| | - Hannu Paulapuro
- Omya Development AG, CH 4665 Oftringen, Switzerland, Helsinki University of Technology, Box 6300, FI-02015 Hut, Finland, KTH Royal Institute of Technology, Teknikringen 30/36, SE-10044 Stockholm, Sweden, and YKI Institute for Surface Chemistry, Box 5607, SE-11486 Stockholm, Sweden
| | - John Daicic
- Omya Development AG, CH 4665 Oftringen, Switzerland, Helsinki University of Technology, Box 6300, FI-02015 Hut, Finland, KTH Royal Institute of Technology, Teknikringen 30/36, SE-10044 Stockholm, Sweden, and YKI Institute for Surface Chemistry, Box 5607, SE-11486 Stockholm, Sweden
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