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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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2
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Luo S, Nasrabadi H, Lutkenhaus JL. Effect of confinement on the bubble points of hydrocarbons in nanoporous media. AIChE J 2016. [DOI: 10.1002/aic.15154] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Sheng Luo
- Harold Vance Dept. of Petroleum Engineering; Texas A&M University; College Station Texas 77843
| | - Hadi Nasrabadi
- Harold Vance Dept. of Petroleum Engineering; Texas A&M University; College Station Texas 77843
| | - Jodie L. Lutkenhaus
- Artie McFerrin Dept. of Chemical Engineering; Texas A&M University; College Station Texas 77843
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3
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Chen W. Phase separation of binary nonadditive hard sphere fluid mixture confined in random porous media. J Chem Phys 2013; 139:154712. [PMID: 24160538 DOI: 10.1063/1.4825178] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
I analyze the fluid-fluid phase separation of nonadditive hard sphere fluid mixture absorbed in random porous media. An equation of state is derived by using the perturbation theory to this complex system with quenched disorders. The results of this theory are in good agreement with those obtained from semi-grand canonical ensemble Monte Carlo simulations. The contact value of the fluid-fluid radial distribution functions of the reference which is the key point of the perturbation process is derived as well, the comparison against Monte Carlo simulations shows that it has an excellent accuracy.
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Affiliation(s)
- W Chen
- Department of Applied Physics, Aalto University, School of Science, P.O. Box 14100, FI-00076 Aalto, Finland
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4
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De Sanctis Lucentini PG, Pellicane G. Critical behavior of symmetrical fluid mixtures in random pores. PHYSICAL REVIEW LETTERS 2008; 101:246101. [PMID: 19113634 DOI: 10.1103/physrevlett.101.246101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Indexed: 05/27/2023]
Abstract
We study the liquid-liquid demixing of a binary mixture with a symmetrical coupling to the quenched disorder by means of computer simulation. The critical point in the thermodynamic limit is estimated both by assuming the knowledge of the critical exponents and independently of them. The finite-size scaling analysis of the susceptibilities and the values of the critical amplitudes show that the universality class of the fluid mixture is compatible with the diluted quenched-Ising model. Our findings extend the class of systems exhibiting the same critical behavior of diluted antiferromagnets.
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5
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Kumar AN, Singh JK. The effects of interaction range, porosity and molecular association on the phase equilibrium of a fluid confined in a disordered porous media. Mol Phys 2008. [DOI: 10.1080/00268970802418963] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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6
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Troyer WE, Holly R, Peemoeller H, Pintar MM. Proton spin-spin relaxation study of hydration of a model nanopore. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2005; 28:238-43. [PMID: 16288854 DOI: 10.1016/j.ssnmr.2005.10.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2005] [Revised: 10/04/2005] [Indexed: 05/05/2023]
Abstract
The hydration pattern of controlled pore glass, with pore diameter of 237 A, was investigated using nuclear magnetic resonance. Water proton spin-spin relaxation decay curves were monitored and modeled as two-component exponential decays as a function of hydration. The results are consistent with a geometric model involving a surface water layer and a bulk-like liquid fraction in the form of a plug. The amount of surface water increases as the sample hydrates, until hydration reached approximately a monolayer, at which point a water plug starts to form in the pore, and grow in length at the expense of the surface layer. The results are also analyzed in terms of, and compared to, a recently developed puddle pore-filling model [S.G. Allen, et al. J. Chem. Phys. 106 (1997) 7802-7809].
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Affiliation(s)
- W E Troyer
- Department of Physics, University of Waterloo, Waterloo, Ont., Canada N2L 3G1
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7
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Melnichenko YB, Wignall GD, Cole DR, Frielinghaus H. Density fluctuations near the liquid-gas critical point of a confined fluid. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2004; 69:057102. [PMID: 15244976 DOI: 10.1103/physreve.69.057102] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2003] [Indexed: 05/24/2023]
Abstract
We report the results of an experimental study of the effect of a dilute silica network on liquid-gas critical phenomena in carbon dioxide (CO2). Using small-angle neutron scattering, we measured the correlation length of the density fluctuations in bulk (xi(bulk)) and confined CO2 (xi(conf)) as a function of temperature and average fluid density. We find that quenched disorder induced by an aerogel suppresses density fluctuations: xi(conf) loses the Ising model divergence characteristic of xi(bulk) and does not exceed the size of pores in the homogeneous region.
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Affiliation(s)
- Y B Melnichenko
- Condensed Matter Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393, USA
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8
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Valiullin R, Furó I. Low-temperature phase separation of a binary liquid mixture in porous materials studied by cryoporometry and pulsed-field-gradient NMR. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2002; 66:031508. [PMID: 12366121 DOI: 10.1103/physreve.66.031508] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2002] [Indexed: 05/23/2023]
Abstract
The low-temperature liquid-liquid phase separation of the partially miscible hexane-nitrobenzene mixture imbibed in porous glasses of different pore sizes from 7 to 130 nm has been studied using 1H NMR (nuclear magnetic resonance) cryoporometry and pulse field gradient NMR methods. The mixture was quenched below both its upper critical solution temperature (T(cr)) and the freezing point of nitrobenzene. The size distribution of frozen nitrobenzene domains was derived through their melting point suppression according to the Gibbs-Thompson relation. The obtained data reveal small initial droplets of nitrobenzene surrounded by hexane, which are created as the temperature is decreased below T(cr) and which thereafter coalesce by a droplet-diffusion mechanism. The inter-relation between the pore size and the found size distribution and shapes of nitrobenzene domains is discussed, as well as several aspects of molecular self-diffusion.
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Affiliation(s)
- Rustem Valiullin
- Division of Physical Chemistry, Department of Chemistry, Royal Institute of Technology, SE-10044 Stockholm, Sweden
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9
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Brennan JK, Dong W. Phase transitions of one-component fluids adsorbed in random porous media: Monte Carlo simulations. J Chem Phys 2002. [DOI: 10.1063/1.1469614] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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10
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Valiullin R, Furó I. Phase separation of a binary liquid mixture in porous media studied by nuclear magnetic resonance cryoporometry. J Chem Phys 2002. [DOI: 10.1063/1.1427706] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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11
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Schöll-Paschinger E, Levesque D, Weis JJ, Kahl G. Phase diagram of a symmetric binary fluid in a porous matrix. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2001; 64:011502. [PMID: 11461257 DOI: 10.1103/physreve.64.011502] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2000] [Revised: 11/27/2000] [Indexed: 05/23/2023]
Abstract
The phase behavior of a binary symmetric fluid in thermal equilibrium with a porous matrix has been studied with the optimized random phase approximation and grand canonical Monte Carlo simulations. Depending on the matrix properties and the matrix-fluid and fluid-fluid interactions we find three types of phase diagram characterized by a tricritical point, a tricritical point with a triple point, or a critical end point. Small changes in the properties of the matrix or in the interactions are demonstrated to lead to drastic modifications of the phase diagram of the fluid, in qualitative agreement with observations in experimental studies. We show, in particular, that the change between the different types of phase diagram is triggered not only by the fluid-fluid interactions (internal parameters) but also by the properties of the matrix and of the matrix-fluid potentials (external parameters).
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Affiliation(s)
- E Schöll-Paschinger
- Institut für Theoretische Physik and Center for Computational Materials Science, TU Wien, Wiedner Hauptstrasse 8-10, A-1040 Vienna, Austria
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12
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Rżysko W, de Pablo JJ, Sokolowski S. Critical behavior of simple fluids confined by microporous materials. J Chem Phys 2000. [DOI: 10.1063/1.1321035] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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13
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Tremblay L, Socol SM, Lacelle S. Simple views on critical binary liquid mixtures in porous glass. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 2000; 61:656-659. [PMID: 11046308 DOI: 10.1103/physreve.61.656] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/1999] [Indexed: 05/23/2023]
Abstract
A simple scenario, different from previous attempts, is proposed to resolve the problem of the slow phase separation dynamics of binary liquid mixtures confined in porous Vycor glass. We demonstrate that simply mutual diffusion, renormalized by critical composition fluctuations and geometrical hindrance of the porous glass, accounts for the slow phase separation kinetics. Capillary invasion studies of porous Vycor glass by the critical isobutyric acid-water mixture, close to the consolute solution temperature, corroborate our analysis.
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Affiliation(s)
- L Tremblay
- Departement de Chimie, Universite de Sherbrooke, Sherbrooke, Quebec, Canada J1K 2R1
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14
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Alvarez M, Levesque D, Weis JJ. Monte Carlo approach to the gas-liquid transition in porous materials. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1999; 60:5495-504. [PMID: 11970424 DOI: 10.1103/physreve.60.5495] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/1999] [Indexed: 04/18/2023]
Abstract
The gas-liquid transition of a "quenched-annealed"(QA) system is studied by grand-canonical Monte Carlo simulation. The "quenched" particles are hard spheres within configurations chosen randomly from those of an equilibrium hard-sphere system at given density. The fluid particles interact with the matrix particles by a hard-core potential and with each other by a hard-core potential and an additional potential of a Lennard-Jones type. Our results are in good qualitative agreement with various theoretical approaches. With increasing matrix density the critical temperature is lowered compared to that of the bulk system and the gap between the gas and liquid densities narrowed. Our simulations confirm, for this QA system, the possibility of two fluid-fluid transitions substituting for the unique gas-liquid transition of the bulk system. They demonstrate the necessity to average over a significant number of matrix realizations in order to obtain a quantitative location of the phase coexistence lines.
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Affiliation(s)
- M Alvarez
- Laboratoire de Physique Théorique, Bâtiment 210, Université de Paris-Sud, 91405 Orsay Cedex, France
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15
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Holly R, Peemoeller H, Choi C, Pintar MM. Proton rotating frame spin-lattice relaxation study of slow motion of pore water. J Chem Phys 1998. [DOI: 10.1063/1.475816] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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