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Liavitskaya T, Paulechka E, Blokhin AV, Shevelyova M. Thermodynamic behavior and polymorphism of 1-butyl-3-methylimidazolium hexafluorophosphate composites with multiwalled carbon nanotubes. THE JOURNAL OF CHEMICAL THERMODYNAMICS 2019; 131:10.1016/j.jct.2018.11.006. [PMID: 33343024 PMCID: PMC7745233 DOI: 10.1016/j.jct.2018.11.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Based on room-temperature densities measured in this research for ionic nanofluids (INFs) with four ionic liquids (ILs), we conclude that evacuation is a necessary step to maximize the IL penetration into multiwalled carbon nanotubes (MWCNT). An improved procedure for reproducible preparation of INFs is proposed. Thermal behavior of five (1-butyl-3-methylimidazolium hexafluorophosphate + MWCNT) samples was studied by adiabatic calorimetry over the temperature range (78 to 370) K. The samples contained from 0.11 to 0.92 mass fraction of the nanophase. Their appearance changed from the fluid to the powder with increasing the MWCNT content. For the fluid samples, the specific heat capacity was found be an additive quantity of the specific heat capacities of the components for the crystal and liquid phases, and the temperatures of phase transitions did not change relative to the bulk values. For the powder-like sample with the highest IL content, a sigmoidal heat capacity curve was observed. Thus, the internal diameter of the studied MWCNT was small enough to switch from the isothermal melting process to the gradual transition from the crystal-like structures to the liquid-like ones.
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Affiliation(s)
- Tatsiana Liavitskaya
- Chemistry Faculty, Belarusian State University, 220030 Minsk, Belarus
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL 35294-1240, United States
| | - Eugene Paulechka
- Chemistry Faculty, Belarusian State University, 220030 Minsk, Belarus
- Applied Chemicals and Materials Division, National Institute of Standards and Technology, Boulder, CO 80305-3337, United States
| | - Andrey V. Blokhin
- Chemistry Faculty, Belarusian State University, 220030 Minsk, Belarus
| | - Marina Shevelyova
- Chemistry Faculty, Belarusian State University, 220030 Minsk, Belarus
- Protein research group, Institute for Biological Instrumentation of the Russian Academy of Sciences, Pushchino, Moscow region, 142290 Russia
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102
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Panhwar GM, Mysyk R, Rojo T, Shaikhutdinov S, Bondarchuk O. Electrowetting of Ionic Liquid on Graphite: Probing via in Situ Electrochemical X-ray Photoelectron Spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:14528-14536. [PMID: 30412414 DOI: 10.1021/acs.langmuir.8b02900] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Thin films of ionic liquid 1-ethyl-3-methylimidazolium bis(fluoromethylsulfonyl)imide ([EMIm][FSI]) vapor-deposited on highly oriented pyrographite (HOPG) were studied by X-ray photoelectron spectroscopy and atomic force microscopy. The results revealed a reversible morphological transition from a "drop-on-layer" structure to a "flat-layer" structure at positive, and not at negative, polarization. The effect is rationalized in terms of electric-field-induced reduction of the liquid-solid transition temperature in the ionic liquid film, when its thickness is comparable to the charge screening length. The observed bias asymmetry of [EMIm][FSI] electrowetting on HOPG is tentatively explained by the bilayer structure at the interface driven by the affinity of the imidazolium ring to the HOPG surface.
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Affiliation(s)
- Ghulam M Panhwar
- CIC Energigune , Parque Tecnológico de Alava , c/A. Einstein 48 , 01510 Miñano , Alava , Spain
| | - Roman Mysyk
- CIC Energigune , Parque Tecnológico de Alava , c/A. Einstein 48 , 01510 Miñano , Alava , Spain
| | - Teófilo Rojo
- CIC Energigune , Parque Tecnológico de Alava , c/A. Einstein 48 , 01510 Miñano , Alava , Spain
| | - Shamil Shaikhutdinov
- Abteilung Chemische Physik , Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6 , 14195 Berlin , Germany
| | - Oleksandr Bondarchuk
- CIC Energigune , Parque Tecnológico de Alava , c/A. Einstein 48 , 01510 Miñano , Alava , Spain
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103
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104
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Lidon P, Marker SC, Wilson JJ, Williams RM, Zipfel WR, Stroock AD. Enhanced Oxygen Solubility in Metastable Water under Tension. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:12017-12024. [PMID: 30221943 DOI: 10.1021/acs.langmuir.8b02408] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Despite its relevance in numerous natural and industrial processes, the solubility of molecular oxygen has never been directly measured in capillary-condensed liquid water. In this article, we measure oxygen solubility in liquid water trapped within nanoporous samples, in metastable equilibrium with a subsaturated vapor. We show that solubility increases two fold at moderate subsaturations (relative humidity ∼0.55). This evolution with relative humidity is in good agreement with a simple thermodynamic prediction using properties of bulk water, previously verified experimentally at positive pressure. Our measurement thus verifies the validity of this macroscopic thermodynamic theory to strong confinement and large negative pressures, where significant nonidealities are expected. This effect has strong implications for important oxygen-dependent chemistries in natural and technological contexts.
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Affiliation(s)
- Pierre Lidon
- Robert Frederick Smith School of Chemical and Biomolecular Engineering , Cornell University , 120 Olin Hall , Ithaca , New York 14853 , United States
- CNRS, Solvay, LOF, UMR 5258, Univ. Bordeaux , 178 avenue du Dr. Schweitzer Pessac F-33600 , France
| | - Sierra C Marker
- Department of Chemistry and Chemical Biology , Cornell University , Baker Lab , Ithaca , New York 14853 , United States
| | - Justin J Wilson
- Department of Chemistry and Chemical Biology , Cornell University , Baker Lab , Ithaca , New York 14853 , United States
| | - Rebecca M Williams
- Department Biomedical Engineering , Cornell University , Weill Hall , Ithaca , New York 14853 , United States
| | - Warren R Zipfel
- Department Biomedical Engineering , Cornell University , Weill Hall , Ithaca , New York 14853 , United States
| | - Abraham D Stroock
- Robert Frederick Smith School of Chemical and Biomolecular Engineering , Cornell University , 120 Olin Hall , Ithaca , New York 14853 , United States
- Kavli Institute at Cornell for Nanoscale Science , Physical Sciences Building , Ithaca , New York 14853 , United States
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105
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Chen Z, Zhao Y, Zhao Y, Thomas H, Zhu X, Möller M. Inclusion of Phase-Change Materials in Submicron Silica Capsules Using a Surfactant-Free Emulsion Approach. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:10397-10406. [PMID: 30095272 DOI: 10.1021/acs.langmuir.8b02435] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Microencapsulation of phase-change materials is of great importance for thermal energy-storage applications. In this work, we report on a facile approach to enclose paraffin in mechanically strong submicron silica capsules without the addition of any classical organic surfactants. A liquid silica precursor polymer, hyperbranched polyethoxysiloxane (PEOS), is used as both silica source and stabilizer of oil-in-water emulsions because of its hydrolysis-induced interfacial activity. Hydrophobic paraffin is microencapsulated in silica with quantitative efficiency simply by emulsifying the mixture of molten paraffin and PEOS in water under ultrasonication or high-shear homogenization. The size of the capsules can be controlled by emulsification energy and rate of subsequent stirring. The silica shell, whose thickness can be easily tuned by varying the paraffin to PEOS ratio, acts as an effective barrier layer retarding significantly the evaporation of enclosed substances; meanwhile, the microencapsulated paraffin maintains the excellent phase-change performance. This technique offers a low-cost, highly scalable, and environmentally friendly process for microencapsulation of paraffin phase-change materials.
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Affiliation(s)
- Zhi Chen
- DWI-Leibniz-Institute for Interactive Materials e.V. and Institute for Technical and Macromolecular Chemistry of RWTH Aachen University , Forckenbeckstrasse 50 , Aachen 52056 , Germany
| | - Yongliang Zhao
- Shanghai Dilato Materials Ltd , Shanghai 200433 , P. R. China
| | - Yue Zhao
- DWI-Leibniz-Institute for Interactive Materials e.V. and Institute for Technical and Macromolecular Chemistry of RWTH Aachen University , Forckenbeckstrasse 50 , Aachen 52056 , Germany
| | - Helga Thomas
- DWI-Leibniz-Institute for Interactive Materials e.V. and Institute for Technical and Macromolecular Chemistry of RWTH Aachen University , Forckenbeckstrasse 50 , Aachen 52056 , Germany
| | - Xiaomin Zhu
- DWI-Leibniz-Institute for Interactive Materials e.V. and Institute for Technical and Macromolecular Chemistry of RWTH Aachen University , Forckenbeckstrasse 50 , Aachen 52056 , Germany
| | - Martin Möller
- DWI-Leibniz-Institute for Interactive Materials e.V. and Institute for Technical and Macromolecular Chemistry of RWTH Aachen University , Forckenbeckstrasse 50 , Aachen 52056 , Germany
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106
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Kohler F, Gagliardi L, Pierre-Louis O, Dysthe DK. Cavity Formation in Confined Growing Crystals. PHYSICAL REVIEW LETTERS 2018; 121:096101. [PMID: 30230887 DOI: 10.1103/physrevlett.121.096101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Indexed: 06/08/2023]
Abstract
Growing crystals form a cavity when placed against a wall. The birth of the cavity is observed both by optical microscopy of sodium chlorate crystals (NaClO_{3}) growing in the vicinity of a glass surface, and in simulations with a thin film model. The cavity appears when growth cannot be maintained in the center of the contact region due to an insufficient supply of growth units through the liquid film between the crystal and the wall. We obtain a nonequilibrium morphology diagram characterizing the conditions under which a cavity appears. Cavity formation is a generic phenomenon at the origin of the formation of growth rims observed in many experiments, and is a source of complexity for the morphology of growing crystals in natural environments. Our results also provide restrictions for the conditions under which compact crystals can grow in confinement.
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Affiliation(s)
- Felix Kohler
- Physics of Geological Processes, The Njord Centre, Department of Geosciences, University of Oslo, Oslo 0316, Norway
| | - Luca Gagliardi
- Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon 69622 Villeurbanne, France
| | - Olivier Pierre-Louis
- Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon 69622 Villeurbanne, France
| | - Dag Kristian Dysthe
- Physics of Geological Processes, The Njord Centre, Department of Geosciences, University of Oslo, Oslo 0316, Norway
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107
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Varadarajan V, Dasgupta C, Ayappa KG. Influence of surface commensurability on the structure and relaxation dynamics of a confined monatomic fluid. J Chem Phys 2018; 149:064503. [DOI: 10.1063/1.5031422] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Affiliation(s)
- Vadhana Varadarajan
- Department of Chemical Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Chandan Dasgupta
- Center for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India
| | - K. G. Ayappa
- Department of Chemical Engineering, Indian Institute of Science, Bangalore 560012, India
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108
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Jasiurkowska-Delaporte M, Kossack W, Kipnusu WK, Sangoro JR, Iacob C, Kremer F. Glassy dynamics of two poly(ethylene glycol) derivatives in the bulk and in nanometric confinement as reflected in its inter- and intra-molecular interactions. J Chem Phys 2018; 149:064501. [PMID: 30111133 DOI: 10.1063/1.5039518] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The inter- and intra-molecular interactions as they evolve in the course of glassy solidification are studied by broadband dielectric-and Fourier-transform infrared-spectroscopy for oligomeric derivatives of poly(ethylene glycol) derivatives, namely, poly(ethylene glycol) phenyl ether acrylate and poly(ethylene glycol) dibenzoate in the bulk and under confinement in nanoporous silica having mean pore diameters 4, 6, and 8 nm, with native and silanized inner surfaces. Analyzing the spectral positions and the oscillator strengths of specific IR absorption bands and their temperature dependencies enables one to trace the changes in the intra-molecular potentials and to compare it with the dielectrically determined primarily inter-molecular dynamics. Special emphasis is given to the calorimetric glass transition temperature Tg and Tαβ ≈ 1.25Tg, where characteristic changes in conformation appear, and the secondary β-relaxation merges with the dynamic glass transition (α-relaxation). Furthermore, the impact of main chain conformations, inter- and intra-molecular hydrogen bonding, and nanometric confinement on the dynamic glass transition is unraveled.
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Affiliation(s)
| | - Wilhelm Kossack
- Institute of Experimental Physics I, University of Leipzig, Linnéstr. 5, Leipzig, Germany
| | - Wycliffe K Kipnusu
- GROC·UJI, Institute of New Imaging Technologies, Universitat Jaume I, Avda. Sos Baynat s/n, 12071 Castellón, Spain
| | - Joshua R Sangoro
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Ciprian Iacob
- Department of Materials Science and Engineering, Penn State University, University Park, Pennsylvania 16802, USA
| | - Friedrich Kremer
- Institute of Experimental Physics I, University of Leipzig, Linnéstr. 5, Leipzig, Germany
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109
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Ito S, Kasuya M, Kawasaki K, Washiya R, Shimazaki Y, Miyauchi A, Kurihara K, Nakagawa M. Selection of Diacrylate Monomers for Sub-15 nm Ultraviolet Nanoimprinting by Resonance Shear Measurement. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:9366-9375. [PMID: 30039971 DOI: 10.1021/acs.langmuir.8b01881] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In UV nanoimprinting, the selection of monomers suitable for sub-15 nm patterning is difficult because the filling behavior of resin at this scale still remains scientifically unclear. We demonstrate sub-15 nm patterning by UV nanoimprinting using silica molds with 20, 15, and 7 nm diameter holes; however, the 7 nm diameter pillar patterns were not fabricated using hydroxy-containing monomers. The filling behavior into silica holes of around 10 nm depended on the chemical structure of the monomers. Resonance shear measurements revealed the following: (1) The viscosities of hydroxy-containing monomers confined between chlorodimethyl(3,3,3-trifluoropropyl)silane (FAS3-Cl)-modified surfaces began to increase at distances shorter than those of the monomers between unmodified surfaces. (2) The monomers confined between tridecafluoro-1,1,2,2-tetrahydrooctyltrimethoxysilane-modified surfaces were squeezed out when the surface-surface distance decreased at less than 7 nm. The measured viscosities between the FAS3-Cl-modified silica surfaces were correlated with the insufficient filling behavior into the silica holes of around 10 nm in UV nanoimprinting. Contact angle measurements provided an additional insight that a higher wettability of the monomers onto the antisticking chemisorbed monolayers resulted in imprinted patterns with higher aspect ratios. Considering the increase in the monomer viscosity in the nanospace and the wettability of monomers onto chemisorbed monolayers, we concluded that the monomer showing low viscosity under confinement and high wettability onto the mold surface was suitable for single-digit nanometer UV nanoimprinting.
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Affiliation(s)
- Shunya Ito
- Institute of Multidisciplinary Research for Advanced Materials (IMRAM) , Tohoku University , 2-1-1 Katahira , Aoba-ku, Sendai , Miyagi 980-8577 , Japan
| | - Motohiro Kasuya
- Institute of Multidisciplinary Research for Advanced Materials (IMRAM) , Tohoku University , 2-1-1 Katahira , Aoba-ku, Sendai , Miyagi 980-8577 , Japan
| | | | | | | | - Akihiro Miyauchi
- Institute of Biomaterials and Bioengineering (IBB) , Tokyo Medical and Dental University , 2-3-10 Kanda-Surugadai , Chiyoda-ku, Tokyo 101-0062 , Japan
| | - Kazue Kurihara
- New Industry Creation Hatchery Center (NICHe) , Tohoku University , 6-6-10 Aramakiazaaoba , Aoba-ku, Sendai , Miyagi 980-8579 , Japan
| | - Masaru Nakagawa
- Institute of Multidisciplinary Research for Advanced Materials (IMRAM) , Tohoku University , 2-1-1 Katahira , Aoba-ku, Sendai , Miyagi 980-8577 , Japan
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110
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Gautam S, Kolesnikov AI, Rother G, Dai S, Qiao ZA, Cole D. Effects of Confinement and Pressure on the Vibrational Behavior of Nano-Confined Propane. J Phys Chem A 2018; 122:6736-6745. [PMID: 30040898 DOI: 10.1021/acs.jpca.8b05028] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Fluids confined in nanopores exhibit significant deviations in their structure and dynamics from the bulk behavior. Although phase, structural, and diffusive behaviors of confined fluids have been investigated and reported extensively, confinement effects on the vibrational properties are less understood. We study the vibrational behavior of propane confined in 1.5 nm nanopores of MCM-41-S using inelastic neutron scattering (INS) and molecular dynamics (MD) simulations. Vibrational spectra have been obtained from INS data as functions of temperature and pressure. At ambient pressure, a strong quasielastic signal observed in the INS spectrum at 80 K suggests that confined propane remains liquid below the bulk phase melting point of 85 K. The quasielastic signal is heavily suppressed when either the pressure is increased to 1 kbar or the temperature is lowered to 30 K, indicating solidification of pore-confined propane. Confinement in MCM-41-S pores results in a glass-like state of propane that exhibits a relatively featureless low-energy vibrational spectrum compared to that of the bulk crystalline propane. Increasing the pressure to 3 kbar results in hardening of the intermolecular and methyl torsional modes. The INS data are used for estimating the isochoric specific heat of confined propane, which is compared with the specific heat of bulk propane reported in literature. Data from MD simulations are used to calculate the vibrational power spectra that agree qualitatively with the experimental data. Simulation data also suggest a reduction of the structural ordering (positional, orientational, and intramolecular) of propane under confinement.
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Affiliation(s)
- Siddharth Gautam
- School of Earth Sciences , The Ohio State University , Columbus , 43210 , Ohio United States
| | | | | | | | - Zhen-An Qiao
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry , Jilin University , Changchun 130012 , China
| | - David Cole
- School of Earth Sciences , The Ohio State University , Columbus , 43210 , Ohio United States
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111
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Böbel A, Knapek CA, Räth C. Scale-free crystallization of two-dimensional complex plasmas: Domain analysis using Minkowski tensors. Phys Rev E 2018; 97:053201. [PMID: 29906865 DOI: 10.1103/physreve.97.053201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Indexed: 11/07/2022]
Abstract
Experiments of the recrystallization processes in two-dimensional complex plasmas are analyzed to rigorously test a recently developed scale-free phase transition theory. The "fractal-domain-structure" (FDS) theory is based on the kinetic theory of Frenkel. It assumes the formation of homogeneous domains, separated by defect lines, during crystallization and a fractal relationship between domain area and boundary length. For the defect number fraction and system energy a scale-free power-law relation is predicted. The long-range scaling behavior of the bond-order correlation function shows clearly that the complex plasma phase transitions are not of the Kosterlitz, Thouless, Halperin, Nelson, and Young type. Previous preliminary results obtained by counting the number of dislocations and applying a bond-order metric for structural analysis are reproduced. These findings are supplemented by extending the use of the bond-order metric to measure the defect number fraction and furthermore applying state-of-the-art analysis methods, allowing a systematic testing of the FDS theory with unprecedented scrutiny: A morphological analysis of lattice structure is performed via Minkowski tensor methods. Minkowski tensors form a complete family of additive, motion covariant and continuous morphological measures that are sensitive to nonlinear properties. The FDS theory is rigorously confirmed and predictions of the theory are reproduced extremely well. The predicted scale-free power-law relation between defect fraction number and system energy is verified for one more order of magnitude at high energies compared to the inherently discontinuous bond-order metric. It is found that the fractal relation between crystalline domain area and circumference is independent of the experiment, the particular Minkowski tensor method, and the particular choice of parameters. Thus, the fractal relationship seems to be inherent to two-dimensional phase transitions in complex plasmas. Minkowski tensor analysis turns out to be a powerful tool for investigations of crystallization processes. It is capable of revealing nonlinear local topological properties, however, still provides easily interpretable results founded on a solid mathematical framework.
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Affiliation(s)
- A Böbel
- Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), Münchner Strasse 20, 82234 Weßling
| | - C A Knapek
- Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), Münchner Strasse 20, 82234 Weßling
| | - C Räth
- Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), Münchner Strasse 20, 82234 Weßling
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112
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113
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Borchardt L, Casco ME, Silvestre-Albero J. Methane Hydrate in Confined Spaces: An Alternative Storage System. Chemphyschem 2018. [DOI: 10.1002/cphc.201701250] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Lars Borchardt
- Department Inorganic Chemistry; TU Dresden; Bergstrasse 66 D-01062 Dresden Germany
| | | | - Joaquin Silvestre-Albero
- Laboratorio de Materiales Avanzados, Departamento de Química Inorgánica-IUMA; Universidad de Alicante; Ctra. San Vicente del Raspeig-Alicante s/n E-03690 San Vicente del Raspeig Spain
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114
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Relation between colour- and phase changes of a leuco dye-based thermochromic composite. Sci Rep 2018; 8:5511. [PMID: 29615711 PMCID: PMC5882991 DOI: 10.1038/s41598-018-23789-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Accepted: 03/20/2018] [Indexed: 11/12/2022] Open
Abstract
Reversible colour change of leuco dye-based composites is in general closely related to their phase change, thus the two phenomena should occur at around the same temperature and should be influenced similarly. However, spatial confinement of the analysed sample affects the change in colour differently compared to its phase transition and the most pronounced effects can be observed during cooling. The bulk composite is coloured while still liquid and the colour hysteresis does not exhibit a loop. In an open-porous medium the colouration coincides well with the crystallization and the colour hysteresis widens to about 4 °C. Microencapsulated composite exhibits two crystallization processes, one of them taking place at the bulk crystallization temperature and the other one at about 20 °C lower. Under such conditions the composite is coloured just before the onset of the second crystallization, i.e. about 15 °C below crystallization in the bulk, and the corresponding colour hysteresis widens to 18 °C. The two crystallization forms are thermally independent and have the same crystalline structure. These effects should be taken into account when designing future applications where the phase-changing materials are implemented.
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115
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Abstract
Abstract
Effects of interfaces on hydrogen-bonded liquids play major roles in nature and technology. Despite their importance, a fundamental understanding of these effects is still lacking. In large parts, this shortcoming is due to the high complexity of these systems, leading to an interference of various interactions and effects. Therefore, it is advisable to take gradual approaches, which start from well designed and defined model systems and systematically increase the level of intricacy towards more complex mimetics. Moreover, it is necessary to combine insights from a multitude of methods, in particular, to link novel preparation strategies and comprehensive experimental characterization with inventive computational and theoretical modeling. Such concerted approach was taken by a group of preparative, experimentally, and theoretically working scientists in the framework of Research Unit FOR 1583 funded by the Deutsche Forschungsgemeinschaft (German Research Foundation). This special issue summarizes the outcome of this collaborative research. In this introductory article, we give an overview of the covered topics and the main results of the whole consortium. The following contributions are review articles or original works of individual research projects.
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Affiliation(s)
- Gerd Buntkowsky
- Institut für Physikalische Chemie , Technische Universität Darmstadt , 64287 Darmstadt , Germany
| | - Michael Vogel
- Institut für Festkörperphysik , Technische Universität Darmstadt , 64295 Darmstadt , Germany
| | - Roland Winter
- Fakultät für Chemie und Chemische Biologie , Technische Universität Dortmund , 44227 Dortmund , Germany
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116
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Sentker K, Zantop AW, Lippmann M, Hofmann T, Seeck OH, Kityk AV, Yildirim A, Schönhals A, Mazza MG, Huber P. Quantized Self-Assembly of Discotic Rings in a Liquid Crystal Confined in Nanopores. PHYSICAL REVIEW LETTERS 2018; 120:067801. [PMID: 29481274 DOI: 10.1103/physrevlett.120.067801] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 11/21/2017] [Indexed: 05/16/2023]
Abstract
Disklike molecules with aromatic cores spontaneously stack up in linear columns with high, one-dimensional charge carrier mobilities along the columnar axes, making them prominent model systems for functional, self-organized matter. We show by high-resolution optical birefringence and synchrotron-based x-ray diffraction that confining a thermotropic discotic liquid crystal in cylindrical nanopores induces a quantized formation of annular layers consisting of concentric circular bent columns, unknown in the bulk state. Starting from the walls this ring self-assembly propagates layer by layer towards the pore center in the supercooled domain of the bulk isotropic-columnar transition and thus allows one to switch on and off reversibly single, nanosized rings through small temperature variations. By establishing a Gibbs free energy phase diagram we trace the phase transition quantization to the discreteness of the layers' excess bend deformation energies in comparison to the thermal energy, even for this near room-temperature system. Monte Carlo simulations yielding spatially resolved nematic order parameters, density maps, and bond-orientational order parameters corroborate the universality and robustness of the confinement-induced columnar ring formation as well as its quantized nature.
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Affiliation(s)
- Kathrin Sentker
- Institut für Materialphysik und -technologie, Technische Universität Hamburg (TUHH), Eißendorferstr. 42, D-21073 Hamburg, Germany
| | - Arne W Zantop
- Max-Planck-Institut für Dynamik und Selbstorganisation, Am Faßberg 17, D-37077 Göttingen, Germany
| | - Milena Lippmann
- Deutsches Elektronen Synchrotron (DESY), Notkestraße 85, D-22607 Hamburg, Germany
| | - Tommy Hofmann
- Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany
| | - Oliver H Seeck
- Deutsches Elektronen Synchrotron (DESY), Notkestraße 85, D-22607 Hamburg, Germany
| | - Andriy V Kityk
- Faculty of Electrical Engineering, Czestochowa University of Technology, Al. Armii Krajowej 17, P-42-200 Czestochowa, Poland
| | - Arda Yildirim
- Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 87, D-12205 Berlin, Germany
| | - Andreas Schönhals
- Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 87, D-12205 Berlin, Germany
| | - Marco G Mazza
- Max-Planck-Institut für Dynamik und Selbstorganisation, Am Faßberg 17, D-37077 Göttingen, Germany
| | - Patrick Huber
- Institut für Materialphysik und -technologie, Technische Universität Hamburg (TUHH), Eißendorferstr. 42, D-21073 Hamburg, Germany
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117
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Nakano H, Tetsuka H, Spencer MJS, Morishita T. Chemical modification of group IV graphene analogs. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2018; 19:76-100. [PMID: 29410713 PMCID: PMC5795708 DOI: 10.1080/14686996.2017.1422224] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 12/25/2017] [Accepted: 12/25/2017] [Indexed: 05/31/2023]
Abstract
Mono-elemental two-dimensional (2D) crystals (graphene, silicene, germanene, stanene, and so on), termed 2D-Xenes, have been brought to the forefront of scientific research. The stability and electronic properties of 2D-Xenes are main challenges in developing practical devices. Therefore, in this review, we focus on 2D free-standing group-IV graphene analogs (graphene quantum dots, silicane, and germanane) and the functionalization of these sheets with organic moieties, which could be handled under ambient conditions. We highlight the present results and future opportunities, functions and applications, and novel device concepts.
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118
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Abstract
The application of ionic liquids as lubricants has attracted substantial interest over the past decade and this has produced a rich literature. The aim of this review is to summarize the main findings about frictional behavior of ionic liquids in the boundary lubrication regime. We first recall why the unusual properties of ionic liquids make them very promising lubricants, and the molecular mechanisms at the origin of their lubricating behavior. We then point out the main challenges to be overcome in order to optimise ionic liquid lubricant performance for common applications. We finally discuss their use in the context of electroactive lubrication.
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119
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Brodrecht M, Kumari B, Breitzke H, Gutmann T, Buntkowsky G. Chemically Modified Silica Materials as Model Systems for the Characterization of Water-Surface Interactions. ACTA ACUST UNITED AC 2018. [DOI: 10.1515/zpch-2017-1059] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Abstract
A series of novel functionalized mesoporous silica-based materials with well-defined pore diameters, surface functionalization and surface morphology is synthesized by co-condensation or grafting techniques and characterized by solid-state NMR spectroscopy, DNP enhanced solid state-NMR and thermodynamic techniques. These materials are employed as host-systems for small-guest molecules like water, small alcohols, carbonic acids, small aromatic molecules, binary mixtures and others. The phase-behavior of these confined guests is studied by combinations of one dimensional solid-state NMR techniques (1H MAS, 2H-line shape analysis, 13C CPMAS) and two-dimensional correlation experiments like 1H-29Si- solid-state HETCOR.
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Affiliation(s)
- Martin Brodrecht
- Eduard-Zintl-Institute of Inorganic and Physical Chemistry, Technical University of Darmstadt , Alarich-Weiss-Str. 8 , D-64287 Darmstadt , Germany
| | - Bharti Kumari
- Eduard-Zintl-Institute of Inorganic and Physical Chemistry, Technical University of Darmstadt , Alarich-Weiss-Str. 8 , D-64287 Darmstadt , Germany
| | - Hergen Breitzke
- Eduard-Zintl-Institute of Inorganic and Physical Chemistry, Technical University of Darmstadt , Alarich-Weiss-Str. 8 , D-64287 Darmstadt , Germany
| | - Torsten Gutmann
- Eduard-Zintl-Institute of Inorganic and Physical Chemistry, Technical University of Darmstadt , Alarich-Weiss-Str. 8 , D-64287 Darmstadt , Germany
| | - Gerd Buntkowsky
- Eduard-Zintl-Institute of Inorganic and Physical Chemistry, Technical University of Darmstadt , Alarich-Weiss-Str. 8 , D-64287 Darmstadt , Germany
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120
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Kuchta B, Dundar E, Formalik F, Llewellyn PL, Firlej L. Adsorption-Induced Structural Phase Transformation in Nanopores. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201708993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Bogdan Kuchta
- Department of Chemistry; MADIREL; Aix-Marseille Université-CNRS; Marseille France
| | - Ege Dundar
- Department of Chemical Engineering; Vrije Universiteit Brussel; Pleinlaan 2 Brussels Belgium
| | - Filip Formalik
- Faculty of Chemistry; Wroclaw University of Science and Technology; 50-370 Wroclaw Poland
| | - Philip L. Llewellyn
- Department of Chemistry; MADIREL; Aix-Marseille Université-CNRS; Marseille France
| | - Lucyna Firlej
- Department of Physics, Laboratoire Coulomb; Université Montpellier; Montpellier France
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121
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Kuchta B, Dundar E, Formalik F, Llewellyn PL, Firlej L. Adsorption-Induced Structural Phase Transformation in Nanopores. Angew Chem Int Ed Engl 2017; 56:16243-16246. [PMID: 29092101 DOI: 10.1002/anie.201708993] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Indexed: 11/08/2022]
Abstract
We report a new type of structural transformation occurring in methane adsorbed in micropores. The observed methane structures are defined by probability distributions of molecular positions. The mechanism of the transformation has been modeled using Monte Carlo method. The transformation is totally determined by a reconstruction of the probability distribution functions of adsorbed molecules. The methane molecules have some freedom to move in the pore but most of the time they are confined to the positions around the high probability adsorption sites. The observed high-probability structures evolve as a function of temperature and pressure. The transformation is strongly discontinuous at low temperature and becomes continuous at high temperature. The mechanism of the transformation is influenced by a competition between different components of the interaction and the thermal energy. The methane structure represents a new state of matter, intermediate between solid and liquid.
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Affiliation(s)
- Bogdan Kuchta
- Department of Chemistry, MADIREL, Aix-Marseille Université-CNRS, Marseille, France
| | - Ege Dundar
- Department of Chemical Engineering, Vrije Universiteit Brussel, Pleinlaan 2, Brussels, Belgium
| | - Filip Formalik
- Faculty of Chemistry, Wroclaw University of Science and Technology, 50-370, Wroclaw, Poland
| | - Philip L Llewellyn
- Department of Chemistry, MADIREL, Aix-Marseille Université-CNRS, Marseille, France
| | - Lucyna Firlej
- Department of Physics, Laboratoire Coulomb, Université Montpellier, Montpellier, France
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122
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Brodrecht M, Klotz E, Lederle C, Breitzke H, Stühn B, Vogel M, Buntkowsky G. A Combined Solid-State NMR, Dielectric Spectroscopy and Calorimetric Study of Water in Lowly Hydrated MCM-41 Samples. Z PHYS CHEM 2017. [DOI: 10.1515/zpch-2017-1030] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The processes of drying mesoporous silica materials and their refilling with water have been examined by magic-angle spinning (MAS) solid-state NMR, broadband dielectric spectroscopy (BDS), and differential scanning calorimetry (DSC). It is shown that different drying protocols strongly influence the amount and types of hydroxy-species inside the pores. It is found that a very good vacuum (≈10−6 bar) is necessary to remove all H2O molecules from the silica matrices in order to accurately refill them with very low amounts of water such as e.g. a mono- or submonolayer coverage of the surface. Time-dependent 1H-NMR-spectra recorded after loading the samples indicate a very specific course of water first existing in a bulk-like form inside the pores and then distributing itself through the pores by hydrogen bonding to surface silanol groups. After assuring accurate sample loading, we were able to investigate lowly hydrated samples of water confined in MCM-41 via DCS and BDS at temperatures below the freezing point of free bulk-water (0°C) and find two non-crystallizing water species with Arrhenius behavior and activation energies of 0.53 eV (51.1 kJ/mol).
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Affiliation(s)
- Martin Brodrecht
- Institut für Physikalische Chemie , Technische Universität Darmstadt , 64287 Darmstadt , Germany
| | - Edda Klotz
- Institut für Festkörperphysik , Technische Universität Darmstadt , 64289 Darmstadt , Germany
| | - Christina Lederle
- Institut für Festkörperphysik , Technische Universität Darmstadt , 64289 Darmstadt , Germany
| | - Hergen Breitzke
- Institut für Physikalische Chemie , Technische Universität Darmstadt , 64287 Darmstadt , Germany
| | - Bernd Stühn
- Institut für Festkörperphysik , Technische Universität Darmstadt , 64289 Darmstadt , Germany
| | - Michael Vogel
- Institut für Festkörperphysik , Technische Universität Darmstadt , 64289 Darmstadt , Germany
| | - Gerd Buntkowsky
- Institut für Physikalische Chemie , Technische Universität Darmstadt , 64287 Darmstadt , Germany
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123
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Kaneko T. Elevation/depression mechanism of freezing points of liquid confined in slit nanopores. MOLECULAR SIMULATION 2017. [DOI: 10.1080/08927022.2017.1350785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Toshihiro Kaneko
- Department of Mechanical Engineering, Tokyo University of Science, Noda, Japan
- Research Institute for Science and Technology (RIST), Tokyo University of Science, Noda, Japan
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124
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Karbowniczek P, Chrzanowska A. Kinetic-contact-driven gigantic energy transfer in a two-dimensional Lennard-Jones fluid confined to a rotating pore. Phys Rev E 2017; 96:053113. [PMID: 29347671 DOI: 10.1103/physreve.96.053113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Indexed: 06/07/2023]
Abstract
A two-dimensional Lennard-Jones system in a circular and rotating container has been studied by means of molecular dynamics technique. A nonequilibrium transition to the rotating stage has been detected in a delayed time since an instant switching of the frame rotation. This transition is attributed to the increase of the density at the wall because of the centrifugal force. At the same time the phase transition occurs, the inner system changes its configuration of the solid-state type into the liquid type. Impact of angular frequency and molecular roughness on the transport properties of the nonrotating and rotating systems is analyzed.
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Affiliation(s)
- Paweł Karbowniczek
- Institute of Physics, Cracow University of Technology, ul. Podchorążych 1, 30-084 Kraków, Poland
| | - Agnieszka Chrzanowska
- Institute of Physics, Cracow University of Technology, ul. Podchorążych 1, 30-084 Kraków, Poland
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125
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Kiyohara K, Soneda Y, Asaka K. Ferroelectric Phase Behaviors in Porous Electrodes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:11574-11581. [PMID: 28796520 DOI: 10.1021/acs.langmuir.7b01787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The phase behavior of ions in porous electrodes is qualitatively different from that in the bulk because of the confinement effect and the interaction between the electrode surface and the electrolyte ions. We found that porous electrodes of which the pore size is close to the size of the electrolyte ions can show ferroelectric phase behaviors in some conditions by Monte Carlo simulations of simple models. The phase behavior of the porous electrodes dramatically changes as a function of the pore size of the porous electrode and that is compared to the phase behavior of typical ferroelectric materials, for which the phase behavior changes as a function of the temperature or the composition. The origin of the phase behavior is discussed in terms of the molecular interaction and the ionic structure inside the porous electrodes. We also found that the density of counterions and that of co-ions inside porous electrodes changes in a nonlinear fashion as a function of the applied voltage, which is in agreement with the experimental results.
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Affiliation(s)
- Kenji Kiyohara
- Inorganic Functional Material Research Institute, National Institute of Advanced Industrial Science and Technology (AIST) , Ikeda, Osaka 563-8577, Japan
| | - Yasushi Soneda
- Research Institute of Energy Frontier, National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba, Ibaraki 305-8564, Japan
| | - Kinji Asaka
- Inorganic Functional Material Research Institute, National Institute of Advanced Industrial Science and Technology (AIST) , Ikeda, Osaka 563-8577, Japan
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126
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Le TT, Striolo A. Propane-Water Mixtures Confined within Cylindrical Silica Nanopores: Structural and Dynamical Properties Probed by Molecular Dynamics. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:11310-11320. [PMID: 28910531 PMCID: PMC5657426 DOI: 10.1021/acs.langmuir.7b03093] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 09/11/2017] [Indexed: 06/07/2023]
Abstract
Despite the multiple length and time scales over which fluid-mineral interactions occur, interfacial phenomena control the exchange of matter and impact the nature of multiphase flow, as well as the reactivity of C-O-H fluids in geologic systems. In general, the properties of confined fluids, and their influence on porous geologic phenomena are much less well understood compared to those of bulk fluids. We used equilibrium molecular dynamics simulations to study fluid systems composed of propane and water, at different compositions, confined within cylindrical pores of diameter ∼16 Å carved out of amorphous silica. The simulations are conducted within a single cylindrical pore. In the simulated system all the dangling silicon and oxygen atoms were saturated with hydroxyl groups and hydrogen atoms, respectively, yielding a total surface density of 3.8 -OH/nm2. Simulations were performed at 300 K, at different bulk propane pressures, and varying the composition of the system. The structure of the confined fluids was quantified in terms of the molecular distribution of the various molecules within the pore as well as their orientation. This allowed us to quantify the hydrogen bond network and to observe the segregation of propane near the pore center. Transport properties were quantified in terms of the mean square displacement in the direction parallel to the pore axis, which allows us to extract self-diffusion coefficients. The diffusivity of propane in the cylindrical pore was found to depend on pressure, as well as on the amount of water present. It was found that the propane self-diffusion coefficient decreases with increasing water loading because of the formation of water bridges across the silica pores, at sufficiently high water content, which hinder propane transport. The rotational diffusion, the lifespan of hydrogen bonds, and the residence time of water molecules at contact with the silica substrate were quantified from the simulated trajectories using the appropriate autocorrelation functions. The simulations contribute to a better understanding of the molecular phenomena relevant to the behavior of fluids in the subsurface.
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Affiliation(s)
- Tran Thi
Bao Le
- Department of Chemical Engineering, University College London, London WC1E 6BT United Kingdom
| | - Alberto Striolo
- Department of Chemical Engineering, University College London, London WC1E 6BT United Kingdom
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127
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Brey JJ, de Soria MIG, Maynar P. Boltzmann kinetic equation for a strongly confined gas of hard spheres. Phys Rev E 2017; 96:042117. [PMID: 29347460 DOI: 10.1103/physreve.96.042117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Indexed: 06/07/2023]
Abstract
A Boltzmann-like kinetic equation for a quasi-two-dimensional gas of hard spheres is derived. The system is confined between two parallel hard plates separated a distance between one and two particle diameters. An entropy Lyapunov function for the equation is identified. In addition to the usual Boltzmann expression, it contains a contribution associated to the confinement of the particles. The steady properties of the system agree with equilibrium statistical mechanics results. Equations describing the energy transfer between the degrees of freedom parallel and perpendicular to the confining plates are obtained for some simple initial configurations. The theoretical predictions are compared with molecular dynamics simulation data and a good agreement is found.
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Affiliation(s)
- J Javier Brey
- Física Teórica, Universidad de Sevilla, Apartado de Correos 1065, E-41080, Sevilla, Spain
| | - M I García de Soria
- Física Teórica, Universidad de Sevilla, Apartado de Correos 1065, E-41080, Sevilla, Spain
| | - P Maynar
- Física Teórica, Universidad de Sevilla, Apartado de Correos 1065, E-41080, Sevilla, Spain
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128
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Mietner JB, Brieler FJ, Lee YJ, Fröba M. Eigenschaften von Wasser in den Poren von periodisch mesoporösen Organosilicas - Nanoabprägung der lokalen Struktur. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201705707] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- J. Benedikt Mietner
- Institut für Anorganische u. Angewandte Chemie, Fachbereich Chemie; Universität Hamburg; Martin-Luther-King-Platz 6 20146 Hamburg Deutschland
- The Hamburg Centre for Ultrafast Imaging; Luruper Chaussee 149 22761 Hamburg Deutschland
| | - Felix J. Brieler
- Institut für Anorganische u. Angewandte Chemie, Fachbereich Chemie; Universität Hamburg; Martin-Luther-King-Platz 6 20146 Hamburg Deutschland
| | - Young Joo Lee
- Institut für Anorganische u. Angewandte Chemie, Fachbereich Chemie; Universität Hamburg; Martin-Luther-King-Platz 6 20146 Hamburg Deutschland
| | - Michael Fröba
- Institut für Anorganische u. Angewandte Chemie, Fachbereich Chemie; Universität Hamburg; Martin-Luther-King-Platz 6 20146 Hamburg Deutschland
- The Hamburg Centre for Ultrafast Imaging; Luruper Chaussee 149 22761 Hamburg Deutschland
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129
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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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130
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Mietner JB, Brieler FJ, Lee YJ, Fröba M. Properties of Water Confined in Periodic Mesoporous Organosilicas: Nanoimprinting the Local Structure. Angew Chem Int Ed Engl 2017; 56:12348-12351. [DOI: 10.1002/anie.201705707] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Indexed: 11/08/2022]
Affiliation(s)
- J. Benedikt Mietner
- Institute of Inorganic & Applied Chemistry, Department of Chemistry; University of Hamburg; Martin-Luther-King-Platz 6 20146 Hamburg Germany
- The Hamburg Centre for Ultrafast Imaging; Luruper Chaussee 149 22761 Hamburg Germany
| | - Felix J. Brieler
- Institute of Inorganic & Applied Chemistry, Department of Chemistry; University of Hamburg; Martin-Luther-King-Platz 6 20146 Hamburg Germany
| | - Young Joo Lee
- Institute of Inorganic & Applied Chemistry, Department of Chemistry; University of Hamburg; Martin-Luther-King-Platz 6 20146 Hamburg Germany
| | - Michael Fröba
- Institute of Inorganic & Applied Chemistry, Department of Chemistry; University of Hamburg; Martin-Luther-King-Platz 6 20146 Hamburg Germany
- The Hamburg Centre for Ultrafast Imaging; Luruper Chaussee 149 22761 Hamburg Germany
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131
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Pignatello JJ, Mitch WA, Xu W. Activity and Reactivity of Pyrogenic Carbonaceous Matter toward Organic Compounds. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:8893-8908. [PMID: 28753285 DOI: 10.1021/acs.est.7b01088] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Pyrogenic carbonaceous matter (PCM) includes environmental black carbon (fossil fuel soot, biomass char), engineered carbons (biochar, activated carbon), and related materials like graphene and nanotubes. These materials contact organic pollutants due to their widespread presence in the environment or through their use in various engineering applications. This review covers recent advances in our understanding of adsorption and chemical reactions mediated by PCM and the links between these processes. It also covers adsorptive processes previously receiving little attention and ignored in models such as steric constraints, physicochemical effects of confinement in nanopores, π interactions of aromatic compounds with polyaromatic surfaces, and very strong hydrogen bonding of ionizable compounds with surface functional groups. Although previous research has regarded carbons merely as passive sorbents, recent studies show that PCM can promote chemical reactions of sorbed contaminants at ordinary temperature, including long-range electron conduction between molecules and between microbes and molecules, local redox reactions between molecules, and hydrolysis. PCM may itself contain redox-active functional groups that are capable of oxidizing or reducing organic compounds and of generating reactive oxygen species (ROS) from oxygen, peroxides, or ozone. Amorphous carbons contain persistent free radicals that may play a role in observed redox reactions and ROS generation. Reactions mediated by PCM can impact the biogeochemical fate of pollutants and lead to useful strategies for remediation.
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Affiliation(s)
- J J Pignatello
- Department of Environmental Sciences, The Connecticut Agricultural Experiment Station , New Haven, Connecticut 06504-1106, United States
| | - William A Mitch
- Department of Civil and Environmental Engineering, Stanford University , 473 Via Ortega, Stanford, California 94305, United States
| | - Wenqing Xu
- Department of Civil and Environmental Engineering, Villanova University , Villanova, Pennsylvania 19085, United States
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132
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Haji-Akbari A, Debenedetti PG. Perspective: Surface freezing in water: A nexus of experiments and simulations. J Chem Phys 2017; 147:060901. [DOI: 10.1063/1.4985879] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Affiliation(s)
- Amir Haji-Akbari
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, USA
| | - Pablo G. Debenedetti
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08540, USA
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133
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Kononenko N, Nikonenko V, Grande D, Larchet C, Dammak L, Fomenko M, Volfkovich Y. Porous structure of ion exchange membranes investigated by various techniques. Adv Colloid Interface Sci 2017; 246:196-216. [PMID: 28511788 DOI: 10.1016/j.cis.2017.05.007] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 05/03/2017] [Indexed: 10/19/2022]
Abstract
A comparative review of various techniques is provided: mercury intrusion porosimetry, nitrogen sorption porosimetry, differential scanning calorimetry (DSC)-based thermoporosimetry, and standard contact porosimetry (SCP), which allows determining pore volume distribution versus pore radius/water binding energy in ion-exchange membranes (IEMs). IEMs in the swollen state have a labile structure involving micro-, meso- and macropores, whose size is a function of the external water vapor pressure. For such materials, the most appropriate methods for quantifying their porosity are DSC and SCP. Especially significant information is given by the SCP method allowing measuring porosimetric curves in a very large pore size range from 1 to 105nm. Experimental results of water distribution in homogeneous and heterogeneous commercial and modified IEMs are presented. The effect of various factors on water distribution is reviewed, i.e. nature of polymeric matrix and functional groups, method for membrane preparation, membrane ageing. A special attention is given to the effect of membrane modification by embedding nanoparticles in their structure. The porosimetric curves are considered along with the results of electrochemical characterization involving the measurements of membrane conductivity, as well as diffusion and electroosmotic permeability. It is shown that addition of nanoparticles may lead to either increase or decrease of water content in IEMs, different ranges of pore size being affected. Hybrid membranes modified with hydrated zirconium dioxide exhibit much higher permselectivity in comparison with the pristine membranes. The diversity of the responses of membrane properties to their modification allows for formation of membranes suitable for fuel cells, electrodialysis or other applications.
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134
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Comtet J, Niguès A, Kaiser V, Coasne B, Bocquet L, Siria A. Nanoscale capillary freezing of ionic liquids confined between metallic interfaces and the role of electronic screening. NATURE MATERIALS 2017; 16:634-639. [PMID: 28346432 PMCID: PMC5446787 DOI: 10.1038/nmat4880] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 02/14/2017] [Indexed: 05/31/2023]
Abstract
Room-temperature ionic liquids (RTILs) are new materials with fundamental importance for energy storage and active lubrication. They are unusual liquids, which challenge the classical frameworks of electrolytes, whose behaviour at electrified interfaces remains elusive, with exotic responses relevant to their electrochemical activity. Using tuning-fork-based atomic force microscope nanorheological measurements, we explore here the properties of confined RTILs, unveiling a dramatic change of the RTIL towards a solid-like phase below a threshold thickness, pointing to capillary freezing in confinement. This threshold is related to the metallic nature of the confining materials, with more metallic surfaces facilitating freezing. This behaviour is interpreted in terms of the shift of the freezing transition, taking into account the influence of the electronic screening on RTIL wetting of the confining surfaces. Our findings provide fresh views on the properties of confined RTIL with implications for their properties inside nanoporous metallic structures, and suggests applications to tune nanoscale lubrication with phase-changing RTILs, by varying the nature and patterning of the substrate, and application of active polarization.
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Affiliation(s)
- Jean Comtet
- Laboratoire de Physique Statistique, Ecole Normale Supérieure, UMR CNRS 8550, PSL Research University, 75005 Paris Cedex 05, France
| | - Antoine Niguès
- Laboratoire de Physique Statistique, Ecole Normale Supérieure, UMR CNRS 8550, PSL Research University, 75005 Paris Cedex 05, France
| | - Vojtech Kaiser
- Laboratoire de Physique Statistique, Ecole Normale Supérieure, UMR CNRS 8550, PSL Research University, 75005 Paris Cedex 05, France
| | - Benoit Coasne
- Laboratoire Interdisciplinaire de Physique, CNRS and Université Grenoble Alpes, UMR CNRS 5588, 38000 Grenoble, France
| | - Lydéric Bocquet
- Laboratoire de Physique Statistique, Ecole Normale Supérieure, UMR CNRS 8550, PSL Research University, 75005 Paris Cedex 05, France
| | - Alessandro Siria
- Laboratoire de Physique Statistique, Ecole Normale Supérieure, UMR CNRS 8550, PSL Research University, 75005 Paris Cedex 05, France
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135
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Stevenson CS, Curro JG, McCoy JD. The glass transition temperature of thin films: A molecular dynamics study for a bead-spring model. J Chem Phys 2017; 146:203322. [DOI: 10.1063/1.4977521] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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136
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Li Z, Jeanmairet G, Méndez-Morales T, Burbano M, Haefele M, Salanne M. Confinement Effects on an Electron Transfer Reaction in Nanoporous Carbon Electrodes. J Phys Chem Lett 2017; 8:1925-1931. [PMID: 28403610 DOI: 10.1021/acs.jpclett.7b00458] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Nanoconfinement generally leads to a drastic effect on the physical and chemical properties of ionic liquids. Here we investigate how the electrochemical reactivity in such media may be impacted inside of nanoporous carbon electrodes. To this end, we study a simple electron transfer reaction using molecular dynamics simulations. The electrodes are held at constant electric potential by allowing the atomic charges on the carbon atoms to fluctuate. We show that the Fe3+/Fe2+ couple dissolved in an ionic liquid exhibits a deviation with respect to Marcus theory. This behavior is rationalized by the stabilization of a solvation state of the Fe3+ cation in the disordered nanoporous electrode that is not observed in the bulk. The simulation results are fitted with a recently proposed two solvation state model, which allows us to estimate the effect of such a deviation on the kinetics of electron transfer inside of nanoporous electrodes.
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Affiliation(s)
- Zhujie Li
- Maison de la Simulation, CEA, CNRS, Univ. Paris-Sud, UVSQ, Université Paris-Saclay , F-91191 Gif-sur-Yvette, France
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Laboratoire PHENIX , F-75005 Paris, France
- Réseau sur le Stockage Électrochimique de l'Énergie (RS2E), FR CNRS 3459 , 80039 Amiens Cedex, France
| | - Guillaume Jeanmairet
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Laboratoire PHENIX , F-75005 Paris, France
- Réseau sur le Stockage Électrochimique de l'Énergie (RS2E), FR CNRS 3459 , 80039 Amiens Cedex, France
| | - Trinidad Méndez-Morales
- Maison de la Simulation, CEA, CNRS, Univ. Paris-Sud, UVSQ, Université Paris-Saclay , F-91191 Gif-sur-Yvette, France
- Réseau sur le Stockage Électrochimique de l'Énergie (RS2E), FR CNRS 3459 , 80039 Amiens Cedex, France
| | - Mario Burbano
- Maison de la Simulation, CEA, CNRS, Univ. Paris-Sud, UVSQ, Université Paris-Saclay , F-91191 Gif-sur-Yvette, France
- Réseau sur le Stockage Électrochimique de l'Énergie (RS2E), FR CNRS 3459 , 80039 Amiens Cedex, France
| | - Matthieu Haefele
- Maison de la Simulation, CEA, CNRS, Univ. Paris-Sud, UVSQ, Université Paris-Saclay , F-91191 Gif-sur-Yvette, France
| | - Mathieu Salanne
- Maison de la Simulation, CEA, CNRS, Univ. Paris-Sud, UVSQ, Université Paris-Saclay , F-91191 Gif-sur-Yvette, France
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Laboratoire PHENIX , F-75005 Paris, France
- Réseau sur le Stockage Électrochimique de l'Énergie (RS2E), FR CNRS 3459 , 80039 Amiens Cedex, France
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137
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Pham AT, Zhuang Y, Detwiler P, Socolar JES, Charbonneau P, Yellen BB. Phase diagram and aggregation dynamics of a monolayer of paramagnetic colloids. Phys Rev E 2017; 95:052607. [PMID: 28618506 DOI: 10.1103/physreve.95.052607] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Indexed: 06/07/2023]
Abstract
We have developed a tunable colloidal system and a corresponding theoretical model for studying the phase behavior of particles assembling under the influence of long-range magnetic interactions. A monolayer of paramagnetic particles is subjected to a spatially uniform magnetic field with a static perpendicular component and a rapidly rotating in-plane component. The sign and strength of the interactions vary with the tilt angle θ of the rotating magnetic field. For a purely in-plane field, θ=90^{∘}, interactions are attractive and the experimental results agree well with both equilibrium and out-of-equilibrium predictions based on a two-body interaction model. For tilt angles 50^{∘}≲θ≲55^{∘}, the two-body interaction gives a short-range attractive and long-range repulsive interaction, which predicts the formation of equilibrium microphases. In experiments, however, a different type of assembly is observed. Inclusion of three-body (and higher-order) terms in the model does not resolve the discrepancy. We further characterize the anomalous regime by measuring the time-dependent cluster size distribution.
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Affiliation(s)
- An T Pham
- NSF Research Triangle Materials Research Science and Engineering Center, Duke University, Durham, North Carolina 27708, USA
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, USA
| | - Yuan Zhuang
- NSF Research Triangle Materials Research Science and Engineering Center, Duke University, Durham, North Carolina 27708, USA
- Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
| | - Paige Detwiler
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Joshua E S Socolar
- NSF Research Triangle Materials Research Science and Engineering Center, Duke University, Durham, North Carolina 27708, USA
- Department of Physics, Duke University, Durham, North Carolina 27708, USA
| | - Patrick Charbonneau
- NSF Research Triangle Materials Research Science and Engineering Center, Duke University, Durham, North Carolina 27708, USA
- Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
- Department of Physics, Duke University, Durham, North Carolina 27708, USA
| | - Benjamin B Yellen
- NSF Research Triangle Materials Research Science and Engineering Center, Duke University, Durham, North Carolina 27708, USA
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, USA
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, USA
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138
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Borreguero JM, Mamontov E. Disruption of Hydrogen-Bonding Network Eliminates Water Anomalies Normally Observed on Cooling to Its Calorimetric Glass Transition. J Phys Chem B 2017; 121:4168-4173. [PMID: 28398063 DOI: 10.1021/acs.jpcb.7b01226] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The calorimetric glass-transition temperature of water is 136 K, but extrapolation of thermodynamic and relaxation properties of water from ambient temperature to below its homogeneous nucleation temperature TH = 235 K predicts divergence at TS = 228 K. The "no-man's land" between the TH and glassy water crystallization temperature of 150 K, which is encountered on warming up from the vitrified state, precludes a straightforward reconciliation of the two incompatible temperature dependences of water properties, above 235 K and below 150 K. The addition of lithium chloride to water allows bypassing both TH and TS on cooling, resulting in the dynamics with no features except the calorimetric glass transition, still at 136 K. We show that lithium chloride prevents hydrogen-bonding network completion in water on cooling, as manifested, in particular, in changing microscopic diffusion mechanism of the water molecules. Thus thermodynamic and relaxation peculiarities exhibited by pure water on cooling to its glass transition, such as the existence of the TH and TS, must be associated specifically with the hydrogen-bonding network.
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Affiliation(s)
- Jose M Borreguero
- Neutron Data Analysis and Visualization Division, Neutron Sciences Directorate, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Eugene Mamontov
- Chemical and Engineering Materials Division, Neutron Sciences Directorate, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
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139
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Motevaselian MH, Aluru NR. An EQT-based cDFT approach for thermodynamic properties of confined fluid mixtures. J Chem Phys 2017; 146:154102. [DOI: 10.1063/1.4979896] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- M. H. Motevaselian
- Department of Mechanical Science and Engineering, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - N. R. Aluru
- Department of Mechanical Science and Engineering, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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140
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Geske J, Drossel B, Vogel M. Structure and dynamics of a silica melt in neutral confinement. J Chem Phys 2017; 146:134502. [DOI: 10.1063/1.4979341] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Julian Geske
- Institut für Festkörperphysik, Technische Universität Darmstadt, Hochschulstraße 6, 64289 Darmstadt, Germany
| | - Barbara Drossel
- Institut für Festkörperphysik, Technische Universität Darmstadt, Hochschulstraße 6, 64289 Darmstadt, Germany
| | - Michael Vogel
- Institut für Festkörperphysik, Technische Universität Darmstadt, Hochschulstraße 6, 64289 Darmstadt, Germany
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141
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Wang LY, Gu F, Wang HJ, Sun ZL. Pressure Profile for an Associating Lennard-Jones Fluid Confined in a Spherical Cavity. J Phys Chem B 2017; 121:2142-2152. [PMID: 28191841 DOI: 10.1021/acs.jpcb.6b09861] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We present the pressure tensor of an associating Lennard-Jones (LJ) fluid confined in a spherical cavity of hard wall, where a high-order density correlation has been taken into account. To give the two-body association potential for calculating the pressure tensor, an angle-average of site-site attraction over all orientations of two particles is performed. Furthermore, the classical density functional theory is employed to obtain the density profile of the confined fluid, by which the normal and tangential pressure profiles are illustrated under various conditions to show the dependence of the pressure tensor on the association strength, number of associating sites, radius of cavity, and bulk density. As an application, the corresponding surface tension is calculated. It is shown that under a strong association interaction (both association strength and the number of associating sites are large), the pressure profiles are depleted from the wall of the cavity instead of the oscillatory behavior under a weak association interaction. Such a tendency is mainly determined by the competition between association interaction and excluded volume interaction. Therefore, the aggregation state and related properties of an associating LJ fluid within a confinement of nanoscale can be efficiently regulated by the association interaction.
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Affiliation(s)
| | | | | | - Zong-Li Sun
- Science and Technology College, North China Electric Power University , Baoding 071051, P. R. China
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142
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Xu WS, Douglas JF, Freed KF. Influence of Pressure on Glass Formation in a Simulated Polymer Melt. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b00080] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Jack F. Douglas
- Materials
Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
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143
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Mandal S, Franosch T. Diverging Time Scale in the Dimensional Crossover for Liquids in Strong Confinement. PHYSICAL REVIEW LETTERS 2017; 118:065901. [PMID: 28234501 DOI: 10.1103/physrevlett.118.065901] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Indexed: 06/06/2023]
Abstract
We study a strongly interacting dense hard-sphere system confined between two parallel plates by event-driven molecular dynamics simulations to address the fundamental question of the nature of the 3D to 2D crossover. As the fluid becomes more and more confined the dynamics of the transverse and lateral degrees of freedom decouple, which is accompanied by a diverging time scale separating 2D from 3D behavior. Relying on the time-correlation function of the transversal kinetic energy, the scaling behavior and its density dependence is explored. Surprisingly, our simulations reveal that its time dependence becomes purely exponential such that memory effects can be ignored. We rationalize our findings quantitatively in terms of an analytic theory which becomes exact in the limit of strong confinement.
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Affiliation(s)
- Suvendu Mandal
- Institut für Theoretische Physik, Universität Innsbruck, Technikerstraße 21A, A-6020 Innsbruck, Austria
| | - Thomas Franosch
- Institut für Theoretische Physik, Universität Innsbruck, Technikerstraße 21A, A-6020 Innsbruck, Austria
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144
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Dundar E, Wexler C, Firlej L, Llewellin P, Kuchta B. Evolution of methane density during melting in nanopores. J Mol Model 2017; 23:44. [PMID: 28154981 DOI: 10.1007/s00894-017-3211-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 01/09/2017] [Indexed: 11/28/2022]
Abstract
Phase properties of gases adsorbed in small nanopores are mainly determined by the pore size and shape as well as the structural heterogeneity of the adsorbate. Here we analyze the evolution of the melting mechanism that occurs in pores <3 nm in size. Melting in slit-shaped graphene pores is compared with melting in SURMOF channel pores with square cross-sections. We show how the melting transformation is related to the adsorption mechanism. We use a graphical representation of the evolution of molecular density as a function of temperature in the nanopores.
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Affiliation(s)
- E Dundar
- Aix Marseille University, CNRS, MADIREL (UMR 7246), 13397, Marseille, France
| | - C Wexler
- Department of Physics and Astronomy, University of Missouri, Columbia, MO, 65211, USA
| | - L Firlej
- Department of Physics and Astronomy, University of Missouri, Columbia, MO, 65211, USA.,Laboratoire Charles Coulomb (L2C), UMR 5221, Université de Montpellier, Montpellier, France
| | - Ph Llewellin
- Aix Marseille University, CNRS, MADIREL (UMR 7246), 13397, Marseille, France
| | - B Kuchta
- Aix Marseille University, CNRS, MADIREL (UMR 7246), 13397, Marseille, France. .,Department of Physics and Astronomy, University of Missouri, Columbia, MO, 65211, USA. .,Department of Chemistry, Wroclaw University of Technology, 50-370, Wroclaw, Poland.
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145
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Nguyen HD, Assumma L, Judeinstein P, Mercier R, Porcar L, Jestin J, Iojoiu C, Lyonnard S. Controlling Microstructure-Transport Interplay in Highly Phase-Separated Perfluorosulfonated Aromatic Multiblock Ionomers via Molecular Architecture Design. ACS APPLIED MATERIALS & INTERFACES 2017; 9:1671-1683. [PMID: 27966862 DOI: 10.1021/acsami.6b12764] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Proton-conducting multiblock polysulfones bearing perfluorosulfonic acid side chains were designed to encode nanoscale phase-separation, well-defined hydrophilic/hydrophobic interfaces, and optimized transport properties. Herein, we show that the superacid side chains yield highly ordered morphologies that can be tailored by best compromising ion-exchange capacity and block lengths. The obtained microstructures were extensively characterized by small-angle neutron scattering (SANS) over an extended range of hydration. Peculiar swelling behaviors were evidenced at two different scales and attributed to the dilution of locally flat polymer particles. We evidence the direct correlation between the quality of interfaces, the topology and connectivity of ionic nanodomains, the block superstructure long-range organization, and the transport properties. In particular, we found that the proton conductivity linearly depends on the microscopic expansion of both ionic and block domains. These findings indicate that neat nanoscale phase-separation and block-induced long-range connectivity can be optimized by designing aromatic ionomers with controlled architectures to improve the performances of polymer electrolyte membranes.
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Affiliation(s)
- Huu-Dat Nguyen
- LEPMI, Université Grenoble Alpes - CNRS , 38000 Grenoble, France
| | - Luca Assumma
- LEPMI, Université Grenoble Alpes - CNRS , 38000 Grenoble, France
| | - Patrick Judeinstein
- Laboratoire Léon Brillouin (LLB), CNRS-CEA, Université Paris-Saclay, CEA Saclay , 91191 Gif-sur-Yvette Cedex, France
| | - Regis Mercier
- Ingénierie des Matériaux Polymères, Université de Lyon , 69622 Villeurbanne, France
| | - Lionel Porcar
- Institut Laue Langevin (ILL) , 38002 Grenoble, France
| | - Jacques Jestin
- Laboratoire Léon Brillouin (LLB), CNRS-CEA, Université Paris-Saclay, CEA Saclay , 91191 Gif-sur-Yvette Cedex, France
| | - Cristina Iojoiu
- LEPMI, Université Grenoble Alpes - CNRS , 38000 Grenoble, France
| | - Sandrine Lyonnard
- INAC-SPrAM, Université Grenoble Alpes - CEA - CNRS , 38000 Grenoble, France
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146
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Mhanna R, Abdel Hamid AR, Dutta S, Lefort R, Noirez L, Frick B, Morineau D. More room for microphase separation: An extended study on binary liquids confined in SBA-15 cylindrical pores. J Chem Phys 2017; 146:024501. [DOI: 10.1063/1.4972126] [Citation(s) in RCA: 11] [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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147
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Affiliation(s)
- Shiguo Zhang
- College
of Materials Science and Engineering, Hunan University, Changsha 410082, China
- Center for Green Chemistry and Catalysis, State Key Laboratory for Oxo Synthesis & Selective Oxidation, State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, No.18, Tianshui Middle Road, 730000 Lanzhou, China
| | - Jiaheng Zhang
- School
of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen 518055, China
| | - Yan Zhang
- College
of Materials Science and Engineering, Hunan University, Changsha 410082, China
| | - Youquan Deng
- Center for Green Chemistry and Catalysis, State Key Laboratory for Oxo Synthesis & Selective Oxidation, State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, No.18, Tianshui Middle Road, 730000 Lanzhou, China
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148
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Yao Y, Ruckdeschel P, Graf R, Butt HJ, Retsch M, Floudas G. Homogeneous Nucleation of Ice Confined in Hollow Silica Spheres. J Phys Chem B 2016; 121:306-313. [DOI: 10.1021/acs.jpcb.6b11053] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yang Yao
- Max-Planck Institute for Polymer Research, 55128 Mainz, Germany
| | - Pia Ruckdeschel
- Physical
Chemistry 1 − Polymer Systems, University of Bayreuth, 95447 Bayreuth, Germany
| | - Robert Graf
- Max-Planck Institute for Polymer Research, 55128 Mainz, Germany
| | | | - Markus Retsch
- Physical
Chemistry 1 − Polymer Systems, University of Bayreuth, 95447 Bayreuth, Germany
| | - George Floudas
- Department
of Physics, University of Ioannina, 45110 Ioannina, Greece
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149
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Mäkilä E, Kivelä H, Shrestha N, Correia A, Kaasalainen M, Kukk E, Hirvonen J, Santos HA, Salonen J. Influence of Surface Chemistry on Ibuprofen Adsorption and Confinement in Mesoporous Silicon Microparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:13020-13029. [PMID: 27951684 DOI: 10.1021/acs.langmuir.6b03413] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The effect of adsorption and confinement on ibuprofen was studied by immersion loading the molecules into porous silicon (PSi) microparticles. The PSi microparticles were modified into thermally oxidized PSi (TOPSi) and thermally hydrocarbonized PSi (THCPSi) to evaluate the effects of the loading solvent and the surface chemistry on the obtainable drug payloads. The payloads, location, and the molecular state of the adsorbed drug were evaluated using thermal analysis. The results showed that after the adsorption of ∼800 mg/cm3 (wdrug/vpores) of drug into the mesopores, depending on the solvent used in the immersion, the drug began to rapidly recrystallize on the external surface of the particles. Moderate concentrations, however, enabled payloads of 800-850 mg/cm3 without excessive surface crystallization, and thus, there was no need for rinsing the samples to remove the externally crystallized portion. The results showed that the confined ibuprofen forms nanocrystals inside of the mesopores after approximately 200 mg/cm3 payloads were obtained, accounting for half of the adsorbed drug amount. The presence of both crystalline and noncrystalline phases was further characterized using variable temperature solid-state nuclear magnetic resonance (NMR) measurements. The interactions between the drug molecules and the pore walls of TOPSi and THCPSi were observed using Fourier transform infrared and 1H NMR spectroscopies, and the hydrogen bonding between the silanol groups of TOPSi and the adsorbed ibuprofen was confirmed, but having only limited effect on the overall state of the confined drug. In vitro drug permeation studies in Caco-2 and Caco-2/HT29 cocultures showed that the adsorption onto hydrophilic or hydrophobic PSi microparticles had no significant effects on the ibuprofen permeation, whether the drug was partially nanocrystalline or completely in a liquidlike state.
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Affiliation(s)
- Ermei Mäkilä
- Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki , Helsinki FI-00014, Finland
| | | | - Neha Shrestha
- Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki , Helsinki FI-00014, Finland
| | - Alexandra Correia
- Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki , Helsinki FI-00014, Finland
| | | | | | - Jouni Hirvonen
- Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki , Helsinki FI-00014, Finland
| | - Hélder A Santos
- Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki , Helsinki FI-00014, Finland
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150
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He X, Shen Y, Hung FR, Santiso EE. Heterogeneous nucleation from a supercooled ionic liquid on a carbon surface. J Chem Phys 2016; 145:211919. [DOI: 10.1063/1.4963336] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Xiaoxia He
- Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, USA
| | - Yan Shen
- Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, USA
| | - Francisco R. Hung
- Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, USA
- Center for Computation & Technology, Louisiana State University, Baton Rouge, Louisiana 70803, USA
| | - Erik E. Santiso
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA
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