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Yang H, Dejam M, Tan SP, Adidharma H. Experimental Study on Phase Transitions of Carbon Dioxide Confined in Nanopores: Evaporation, Melting, Sublimation, and Triple Point. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:16060-16068. [PMID: 37917914 DOI: 10.1021/acs.langmuir.3c02209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2023]
Abstract
Capillary phase transitions (evaporation, melting, and sublimation) and the pore triple point of CO2 confined in MCM-41 mesoporous media with a pore diameter of 3.5 nm have been studied by using an isochoric heating procedure in a high-pressure low-temperature differential scanning calorimeter over a pressure range of 0.5-40.5 bar. The procedure is validated by the agreement between the measured conditions of bulk evaporation/sublimation and literature data. The main finding in this work is that the solid-to-fluid phase transitions of CO2 in MCM-41 shift to temperatures higher than those of the corresponding bulk phase transitions. It is also found that the formation of a solid phase of CO2 in MCM-41 does not require the presence of a liquid or solid in the bulk. The capillary-melting and capillary-evaporation curves approach each other as temperature decreases until they meet at the pore triple point. The effect of pressure on capillary melting temperature is significant at pressures close to the pore triple point. Furthermore, the capillary-melting curve approaches the bulk saturated vapor-pressure curve as temperature increases, thus hinting an agreement with the prediction by molecular dynamics simulation in the literature that the curves eventually intersect each other at a high temperature and pressure. Based on the measured capillary phase transitions, the pore triple-point temperature and pressure of nanoconfined CO2 are bracketed and found to be much lower than those of the bulk triple point.
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Affiliation(s)
- Huan Yang
- Department of Energy and Petroleum Engineering, College of Engineering and Physical Sciences, University of Wyoming, 1000 E. University Avenue, Laramie, Wyoming 82071-2000, United States
| | - Morteza Dejam
- Department of Energy and Petroleum Engineering, College of Engineering and Physical Sciences, University of Wyoming, 1000 E. University Avenue, Laramie, Wyoming 82071-2000, United States
| | - Sugata P Tan
- Planetary Science Institute, 1700 East Fort Lowell, Suite 106, Tucson, Arizona 85719-2395, United States
| | - Hertanto Adidharma
- Department of Chemical and Biomedical Engineering, College of Engineering and Physical Sciences, University of Wyoming, 1000 E. University Avenue, Laramie, Wyoming 82071-2000, United States
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Yang H, Dejam M, Tan SP, Adidharma H. First-order and gradual phase transitions of ethane confined in MCM-41. Phys Chem Chem Phys 2022; 24:18161-18168. [PMID: 35861178 DOI: 10.1039/d2cp02530b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The first-order phase transition of ethane confined in MCM-41, i.e., capillary condensation, has been measured using an isochoric cooling procedure by differential scanning calorimetry (DSC) under conditions ranging from 206 K and 1.1 bar up to the pore critical point (PCP). The PCP has also been determined using the three-line method developed earlier based on the vanishing heat of phase transition. As in the bulk phase, no first-order phase transition can occur above the critical point, which also implies that vapor can transform into liquid gradually by following a path around the critical point through the supercritical region. For the first time, the gradual phase transition is demonstrated with ethane in MCM-41, which is achieved through a multistep process with paths proceeding around the PCP without crossing the capillary-condensation curve. The occurrence of the gradual phase transition in nanopores, thus the confined supercriticality, is confirmed while our consistent DSC measurements are also well demonstrated.
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Affiliation(s)
- Huan Yang
- Department of Petroleum Engineering, College of Engineering and Applied Science, University of Wyoming, 1000 E. University Avenue, Laramie, WY, 82071-2000, USA.
| | - Morteza Dejam
- Department of Petroleum Engineering, College of Engineering and Applied Science, University of Wyoming, 1000 E. University Avenue, Laramie, WY, 82071-2000, USA.
| | - Sugata P Tan
- Planetary Science Institute, Tucson, Arizona, 85719-2395, USA
| | - Hertanto Adidharma
- Department of Petroleum Engineering, College of Engineering and Applied Science, University of Wyoming, 1000 E. University Avenue, Laramie, WY, 82071-2000, USA. .,Department of Chemical Engineering, College of Engineering and Applied Science, University of Wyoming, 1000 E. University Avenue, Laramie, WY, 82071-2000, USA
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3
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Douglas M. Ruthven: In Memoriam of a Great Scholar and a Caring Friend. CHEM-ING-TECH 2022. [DOI: 10.1002/cite.202200018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Abstract
We investigate particle diffusion in a heterogeneous medium limited by a surface where sorption–desorption processes are governed by a kinetic equation. We consider that the dynamics of the particles present in the medium are governed by a diffusion equation with a spatial dependence on the diffusion coefficient, i.e., K(x) = D|x|−η, with −1 < η and D = const, respectively. This system is analyzed in a semi-infinity region, i.e., the system is defined in the interval [0,∞) for an arbitrary initial condition. The solutions are obtained and display anomalous spreading, that is, the dynamics may be viewed as anomalous diffusion, which in turn is related, and hence, the model can be directly applied to several complex systems ranging from biological fluids to electrolytic cells.
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Enninful HRNB, Schneider D, Enke D, Valiullin R. Impact of Geometrical Disorder on Phase Equilibria of Fluids and Solids Confined in Mesoporous Materials. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:3521-3537. [PMID: 33724041 DOI: 10.1021/acs.langmuir.0c03047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Porous solids used in practical applications often possess structural disorder over broad length scales. This disorder strongly affects different properties of the substances confined in their pore spaces. Quantifying structural disorder and correlating it with the physical properties of confined matter is thus a necessary step toward the rational use of porous solids in practical applications and process optimization. The present work focuses on recent advances made in the understanding of correlations between the phase state and geometric disorder in nanoporous solids. We overview the recently developed statistical theory for phase transitions in a minimalistic model of disordered pore networks: linear chains of pores with statistical disorder. By correlating its predictions with various experimental observations, we show that this model gives notable insight into collective phenomena in phase-transition processes in disordered materials and is capable of explaining self-consistently the majority of the experimental results obtained for gas-liquid and solid-liquid equilibria in mesoporous solids. The potentials of the theory for improving the gas sorption and thermoporometry characterization of porous materials are discussed.
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Affiliation(s)
- Henry R N B Enninful
- Felix Bloch Institute for Solid State Physics, Leipzig University, Linnéstr. 5, 04103 Leipzig, Germany
| | - Daniel Schneider
- Felix Bloch Institute for Solid State Physics, Leipzig University, Linnéstr. 5, 04103 Leipzig, Germany
| | - Dirk Enke
- Institute of Chemical Technology, Leipzig University, Linnéstr. 3, 04103 Leipzig, Germany
| | - Rustem Valiullin
- Felix Bloch Institute for Solid State Physics, Leipzig University, Linnéstr. 5, 04103 Leipzig, Germany
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6
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Abstract
AbstractLabeling in diffusion measurements by pulsed field gradient (PFG) NMR is based on the observation of the phase of nuclear spins acquired in a constant magnetic field with purposefully superimposed field gradients. This labeling does in no way affect microdynamics and provides information about the probability distribution of molecular displacements as a function of time. An introduction of the measuring principle is followed by a detailed description of the ranges of measurements and their limitation. Particular emphasis is given to an explanation of possible pitfalls in the measurements and the ways to circumvent them. Showcases presented for illustrating the wealth of information provided by PFG NMR include a survey on the various patterns of concentration dependence of intra-particle diffusion and examples of transport inhibition by additional transport resistances within the nanoporous particles and on their external surface. The latter information is attained by combination with the outcome of tracer exchange experiments, which are shown to become possible via a special formalism of PFG NMR data analysis. Further evidence provided by PFG NMR concerns diffusion enhancement in pore hierarchies, diffusion anisotropy and the impact of diffusion on chemical conversion in porous catalysts. A compilation of the specifics of PFG NMR and of the parallels with other measurement techniques concludes the paper.
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Qiu X, Tan SP, Dejam M, Adidharma H. Isochoric measurement of the evaporation point of pure fluids in bulk and nanoporous media using differential scanning calorimetry. Phys Chem Chem Phys 2020; 22:7048-7057. [DOI: 10.1039/d0cp00900h] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Evaporation-point measurement of pure fluids in bulk and nanopores using an isochoric heating process.
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Affiliation(s)
- Xingdong Qiu
- Department of Petroleum Engineering
- College of Engineering and Applied Science
- University of Wyoming
- USA
| | | | - Morteza Dejam
- Department of Petroleum Engineering
- College of Engineering and Applied Science
- University of Wyoming
- USA
| | - Hertanto Adidharma
- Department of Petroleum Engineering
- College of Engineering and Applied Science
- University of Wyoming
- USA
- Department of Chemical Engineering
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Schneider D, Kondrashova D, Valiullin R. Phase transitions in disordered mesoporous solids. Sci Rep 2017; 7:7216. [PMID: 28775331 PMCID: PMC5543148 DOI: 10.1038/s41598-017-07406-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 06/23/2017] [Indexed: 11/20/2022] Open
Abstract
Fluids confined in mesoporous solids exhibit a wide range of physical behavior including rich phase equilibria. While a notable progress in their understanding has been achieved for fluids in materials with geometrically ordered pore systems, mesoporous solids with complex pore geometries still remain a topic of active research. In this work we study phase transitions occurring in statistically disordered linear chains of pores with different pore sizes. By considering, quite generally, two phase change mechanisms, nucleation and phase growth, occurring simultaneously we obtain the boundary transitions and the scanning curves resulting upon reversing the sign of the evolution of the chemical potential at different points along the main transition branches. The results obtained are found to reproduces the key experimental observations, including the emergence of hysteresis and the scanning behavior. By deriving the serial pore model isotherm we suggest a robust framework for reliable structural analysis of disordered mesoporous solids.
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Affiliation(s)
- Daniel Schneider
- Felix Bloch Institute for Solid State Physics, University of Leipzig, Leipzig, Germany
| | - Daria Kondrashova
- Felix Bloch Institute for Solid State Physics, University of Leipzig, Leipzig, Germany
| | - Rustem Valiullin
- Felix Bloch Institute for Solid State Physics, University of Leipzig, Leipzig, Germany.
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Guimarães VG, Ribeiro HV, Li Q, Evangelista LR, Lenzi EK, Zola RS. Unusual diffusing regimes caused by different adsorbing surfaces. SOFT MATTER 2015; 11:1658-1666. [PMID: 25633342 DOI: 10.1039/c5sm00151j] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A confined liquid with dispersed neutral particles is theoretically studied when the limiting surfaces present different dynamics for the adsorption-desorption phenomena. The investigation considers different non-singular kernels in the kinetic equations at the walls, where the suitable choice of the kernel can account for the relative importance of physisorption or chemisorption. We find that even a small difference in the adsorption-desorption rate of one surface (relative to the other) can drastically affect the behavior of the whole system. The surface and bulk densities and the dispersion are calculated when several scenarios are considered and anomalous-like behaviors are found. The approach described here is closely related to experimental situations, and can be applied in several contexts such as dielectric relaxation, diffusion-controlled relaxation in liquids, liquid crystals, and amorphous polymers.
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Affiliation(s)
- Veridiana G Guimarães
- Departamento de Física, Universidade Estadual de Maringá, Avenida Colombo 5790, 87020-900 Maringá, Paraná, Brazil.
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Kärger J, Valiullin R. Mass transfer in mesoporous materials: the benefit of microscopic diffusion measurement. Chem Soc Rev 2013; 42:4172-97. [DOI: 10.1039/c3cs35326e] [Citation(s) in RCA: 193] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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12
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Probing the impact of advanced melting and advanced adsorption phenomena on the accuracy of pore size distributions from cryoporometry and adsorption using NMR relaxometry and diffusometry. J Colloid Interface Sci 2012; 385:183-92. [DOI: 10.1016/j.jcis.2012.07.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 06/21/2012] [Accepted: 07/03/2012] [Indexed: 10/28/2022]
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13
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Zeigermann P, Naumov S, Mascotto S, Kärger J, Smarsly BM, Valiullin R. Diffusion in hierarchical mesoporous materials: applicability and generalization of the fast-exchange diffusion model. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:3621-3632. [PMID: 22260082 DOI: 10.1021/la2047432] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Transport properties of cyclohexane confined to a silica material with an ordered, bimodal pore structure have been studied by means of pulsed field gradient nuclear magnetic resonance. A particular organization of the well-defined pore structure, composed of a collection of spatially ordered, spherical mesopores interconnected via narrow worm-like pores, allowed for a quantitative analysis of the diffusion process in a medium with spatially ordered distribution of the fluid density for a broad range of the gas-liquid equilibria. The measured diffusion data were interpreted in terms of effective diffusivities, which were determined within a microscopic model considering long-range molecular trajectories constructed by assembling the alternating pieces of displacement in the two constituting pore spaces. It has further been found that for the system under study, in particular, and for mesoporous materials with multiple porosities, in general, this generalized model simplifies to the conventional fast-exchange model used in the literature. Thus, not only was justification of the applicability of the fast-exchange model to a diversity of mesoporous materials provided, but the diffusion parameters entering the fast-exchange model were also exactly defined. The equation resulting in this way was found to nicely reproduce the experimentally determined diffusivities, establishing a methodology for targeted fine-tuning of transport properties of fluids in hierarchical materials with multiple porosities.
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Affiliation(s)
- P Zeigermann
- Institute for Experimental Physics I, University of Leipzig, Leipzig, Germany
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14
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Horikawa T, Do DD, Nicholson D. Capillary condensation of adsorbates in porous materials. Adv Colloid Interface Sci 2011; 169:40-58. [PMID: 21937014 DOI: 10.1016/j.cis.2011.08.003] [Citation(s) in RCA: 161] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Revised: 08/26/2011] [Accepted: 08/27/2011] [Indexed: 11/30/2022]
Abstract
Hysteresis in capillary condensation is important for the fundamental study and application of porous materials, and yet experiments on porous materials are sometimes difficult to interpret because of the many interactions and complex solid structures involved in the condensation and evaporation processes. Here we make an overview of the significant progress in understanding capillary condensation and hysteresis phenomena in mesopores that have followed from experiment and simulation applied to highly ordered mesoporous materials such as MCM-41 and SBA-15 over the last few decades.
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Affiliation(s)
- Toshihide Horikawa
- School of Chemical Engineering, University of Queensland, St. Lucia, Qld 4072, Australia
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15
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Furtado F, Galvosas P, Gonçalves M, Kopinke FD, Naumov S, Rodríguez-Reinoso F, Roland U, Valiullin R, Kärger J. Guest Diffusion in Interpenetrating Networks of Micro- and Mesopores. J Am Chem Soc 2011; 133:2437-43. [DOI: 10.1021/ja109235c] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Filipe Furtado
- Department of Environmental Engineering, UFZ−Helmholtz Centre for Environmental Research, Permoserstrasse 15, 04318 Leipzig, Germany
- Department of Interface Physics, University of Leipzig, Linnéstrasse 5, D-04103 Leipzig, Germany
| | - Petrik Galvosas
- Department of Interface Physics, University of Leipzig, Linnéstrasse 5, D-04103 Leipzig, Germany
- MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6140, New Zealand
| | - Maraisa Gonçalves
- Departamento de Química Inorgánica, Universidad de Alicante, Apartado 99, 03080 Alicante, Spain
| | - Frank-Dieter Kopinke
- Department of Environmental Engineering, UFZ−Helmholtz Centre for Environmental Research, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Sergej Naumov
- Department of Interface Physics, University of Leipzig, Linnéstrasse 5, D-04103 Leipzig, Germany
| | | | - Ulf Roland
- Department of Environmental Engineering, UFZ−Helmholtz Centre for Environmental Research, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Rustem Valiullin
- Department of Interface Physics, University of Leipzig, Linnéstrasse 5, D-04103 Leipzig, Germany
| | - Jörg Kärger
- Department of Interface Physics, University of Leipzig, Linnéstrasse 5, D-04103 Leipzig, Germany
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Valiullin R, Kärger J. The Impact of Mesopores on Mass Transfer in Nanoporous Materials: Evidence of Diffusion Measurement by NMR. CHEM-ING-TECH 2011. [DOI: 10.1002/cite.201000208] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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17
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Adem Z, Caro J, Furtado F, Galvosas P, Krause CB, Kärger J. Tracing pore-space heterogeneities in X-type zeolites by diffusion studies. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:416-419. [PMID: 21117674 DOI: 10.1021/la103816r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Pore-space homogeneity of zeolite NaX was probed by pulsed field gradient (PFG) NMR diffusion studies with n-butane as a guest molecule. At a loading of 0.75 molecules per supercage, a wide spectrum of diffusivities was observed. Guest molecules in the (well-shaped) zeolite crystallites were thus found to experience pore spaces of quite different properties. After loading enhancement to 3 molecules per supercage, however, molecular propagation ideally followed the laws of normal diffusion in homogeneous media. At sufficiently high guest concentrations, sample heterogeneity was thus found to be of no perceptible influence on the guest mobilities anymore.
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Affiliation(s)
- Ziad Adem
- Department of Interface Physics, University of Leipzig, Linnéstrasse 5, 04103 Leipzig, Germany
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Hitchcock I, Chudek JA, Holt EM, Lowe JP, Rigby SP. NMR studies of cooperative effects in adsorption. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:18061-18070. [PMID: 21043443 DOI: 10.1021/la103584k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The conversion of gas adsorption isotherms into pore size distributions generally relies upon the assumption of thermodynamically independent pores. Hence, pore-pore cooperative adsorption effects, which might result in a significantly skewed pore size distribution, are neglected. In this work, cooperative adsorption effects in water adsorption on a real, amorphous, mesoporous silica material have been studied using magnetic resonance imaging (MRI) and pulsed-gradient stimulated-echo (PGSE) NMR techniques. Evidence for advanced adsorption can be seen directly using relaxation time weighted MRI. The number and spatial distributions of pixels containing pores of different sizes filled with condensate have been analyzed. The spatial distribution of filled pores has been found to be highly nonrandom. Pixels containing the largest pores present in the material have been observed to fill in conjunction with pixels containing much smaller pores. PGSE NMR has confirmed the spatially extensive nature of the adsorbed ganglia. Thus, long-range (≥40 μm) cooperative adsorption effects, between larger pores associated with smaller pores, occur within mesoporous materials. The NMR findings have also suggested particular types of pore filling mechanisms occur within the porous solid studied.
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Affiliation(s)
- Iain Hitchcock
- Department of Chemical Engineering, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
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19
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Diffusion and phase equilibria of binary fluids in mesopores. ADSORPTION 2010. [DOI: 10.1007/s10450-010-9290-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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20
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Chmelik C, Kärger J. In situ study on molecular diffusion phenomena in nanoporous catalytic solids. Chem Soc Rev 2010; 39:4864-84. [PMID: 20972502 DOI: 10.1039/c0cs00100g] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
As an omnipresent phenomenon in nature, diffusion is among the rate-determining processes in many technological processes. This is in particular true for catalytic conversion in nanoporous materials. We provide a critical review of the possibilities of exploring diffusion phenomena over microscopic dimensions in such media by direct experimental observation. By monitoring the probability distribution of molecular displacements as a function of time, the pulsed field gradient technique of NMR (PFG NMR) records the rate of molecular re-distribution. By varying the observation time, PFG NMR is thus able to trace even hierarchies of transport resistances as occurring, e.g., in catalyst particles in the form of binder-compacted assemblages of zeolite crystallites. Alternatively, and complementary to this information, interference microscopy (IFM) and IR microscopy (IRM) are able to follow the evolution of intracrystalline concentration profiles during uptake and release. This allows, in particular, an accurate quantification of the transport resistances on the surface of the individual crystallites and of the probability that reactant molecules from the gas phase, upon colliding with the external surface, are able to penetrate through such "surface barriers" into the crystal bulk phase. Being able to distinguish between different molecular species, IRM is able to record the evolution of intracrystalline concentration profiles even during multi-component adsorption and catalytic reactions (169 references).
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Affiliation(s)
- Christian Chmelik
- University of Leipzig, Faculty for Physics and Earth Sciences, Linnéstraße 5, D-04103 Leipzig, Germany.
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21
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Kärger J, Chmelik C, Heinke L, Valiullin R. A new view of diffusion in nanoporous materials. CHEM-ING-TECH 2010. [DOI: 10.1002/cite.201000038] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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22
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Kondrashova D, Reichenbach C, Valiullin R. Probing pore connectivity in random porous materials by scanning freezing and melting experiments. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:6380-6385. [PMID: 20095536 DOI: 10.1021/la904062h] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Freezing and melting behavior of nitrobenzene confined to pores of Vycor porous glass with random pore structure has been studied by means of nuclear magnetic resonance cryoporometry. The two transitions are found to reveal a broad hysteresis. To get deeper insight into the mechanisms leading to this phenomenon, scanning experiments exploiting temperature reversal upon incomplete freezing or melting have been performed. In this way, it was found that different cooling and warming histories result in different solid-liquid configurations within the pore system. Further evolution of the thus-attained configurations with changing temperature unveiled important information about the transition paths. In particular, these experiments indicated the occurrence of a pronounced pore blocking for freezing, resulting in freezing transitions via invasion percolation. The melting, on the other hand, is found to occur homogeneously over the whole pore network.
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Affiliation(s)
- D Kondrashova
- Department of Interface Physics, University of Leipzig, Linnestr. 5, D-04103 Leipzig, Germany
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23
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Neouze MA, Litschauer M. Confinement of 1-Butyl-3-methylimidazolium Nitrate in Metallic Silver. J Phys Chem B 2008; 112:16721-5. [DOI: 10.1021/jp8079606] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Marie-Alexandra Neouze
- Institute of Materials Chemistry, Vienna University of Technology, Getreidemarkt 9/165, 1060 Vienna, Austria
| | - Marco Litschauer
- Institute of Materials Chemistry, Vienna University of Technology, Getreidemarkt 9/165, 1060 Vienna, Austria
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Dvoyashkin M, Khokhlov A, Valiullin R, Kärger J. Freezing of fluids in disordered mesopores. J Chem Phys 2008; 129:154702. [DOI: 10.1063/1.2992574] [Citation(s) in RCA: 26] [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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