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Antoni Czarnecki M, Warchoł J, Orzechowski K, Beć K, Huck CW. Soft confinement of water in aliphatic alcohols: MIR/NIR spectroscopic and DFT studies. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 323:124851. [PMID: 39084017 DOI: 10.1016/j.saa.2024.124851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 07/12/2024] [Accepted: 07/17/2024] [Indexed: 08/02/2024]
Abstract
Here, we present the first examination of the state of water under a soft confinement in eight aliphatic alcohols including cyclopentanol, 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-decanol, 2-octanol and 3-octanol. Due to relatively large size of the aliphatic part, water has limited solubility in all studied alcohols. Water content in saturated solutions was determined by Karl Fischer titration and correlated with the spectroscopic data. This way, we determined the molar absorptivity of the ν2+ν3 combination mode. The effect of addition of water and temperature variation was monitored by ATR-IR and NIR spectroscopy. Analysis of the experimental results was guided by DFT calculations, which provided the structures, harmonic MIR spectra and binding energies of selected alcohol-water complexes. Our studies demonstrated that the state of water in alcohols is related to its solubility, which depends on structure of solvent molecules. The solubility of water in 1-alcohols decreases on increasing of the chain length, but for long chain alcohols this effect is less evident. More apparent solubility reduction appears in going from the primary to secondary alcohols. The effective shielding of the OH group in the linear alcohols is achieved when on both sides of the OH group are ethyl or longer substituents, while the shielding by methyl groups is less efficient. Water is much better soluble in the cyclic alcohols as compared with the linear ones due to better accessibility of the OH group. The soft confinement of water in aliphatic alcohols allows for flexible structural arrangements and interactions. Even at low water content, we did not observe free molecules of water. At these conditions, the molecules of water are singly or doubly bonded to the OH groups from the alcohol. Increasing solubility of water reduces the number of the free OH groups and leads to formation of water clusters. Obtained results allow concluding that in alcohols with sizable aliphatic part the molecules of water are confined in the vicinity of the OH groups.
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Affiliation(s)
| | - Justyna Warchoł
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
| | - Kazimierz Orzechowski
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
| | - Krzysztof Beć
- Institute of Analytical Chemistry and Radiochemistry, University of Innsbruck, Innrain 80-82, A6020 Innsbruck, Austria
| | - Christian W Huck
- Institute of Analytical Chemistry and Radiochemistry, University of Innsbruck, Innrain 80-82, A6020 Innsbruck, Austria
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2
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Tripathy M, Bharadwaj S, van der Vegt NFA. Solvation shell thermodynamics of extended hydrophobic solutes in mixed solvents. J Chem Phys 2022; 156:164901. [DOI: 10.1063/5.0090646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The ability of various cosolutes and cosolvents to enhance or quench solvent density fluctuations at solute–water interfaces has crucial implications on the conformational equilibrium of macromolecules such as polymers and proteins. Herein, we use an extended hydrophobic solute as a model system to study the effect of urea and methanol on the density fluctuations in the solute’s solvation shell and the resulting thermodynamics. On strengthening the solute–water/cosolute repulsive interaction, we observe distinct trends in the mutual affinities between various species in, and the thermodynamic properties of, the solvation shell. These trends strongly follow the respective trends in the preferential adsorption of urea and methanol: solute–water/cosolute repulsion strengthens, urea accumulation decreases, and methanol accumulation increases. Preferential accumulation of urea is found to quench the density fluctuations around the extended solute, leading to a decrease in the compressibility of the solvation shell. In contrast, methanol accumulation enhances the density fluctuations, leading to an increase in the compressibility. The mode of action of urea and methanol seems to be strongly coupled to their hydration behavior. The observations from this simple model is discussed in relation to urea driven swelling and methanol induced collapse of some well-known thermo-responsive polymers.
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Affiliation(s)
- Madhusmita Tripathy
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Swaminath Bharadwaj
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Nico F. A. van der Vegt
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, 64287 Darmstadt, Germany
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3
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Trabelsi S, Tlili M, Abdelmoulahi H, Bouazizi S, Nasr S, González MA, Bellissent-Funel MC, Darpentigny J. Intermolecular interactions in an equimolar methanol-water mixture: Neutron scattering, DFT, NBO, AIM, and MD investigations. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2021.118131] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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4
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Zhai Y, Luo P, Waller J, Self JL, Harriger LW, Z Y, Faraone A. Dynamics of molecular associates in methanol/water mixtures. Phys Chem Chem Phys 2022; 24:2287-2299. [PMID: 35015001 DOI: 10.1039/d1cp04726d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The dynamics of molecular associates in a methanol/water mixture was investigated using quasielastic neutron scattering. By measuring the signal from four methanol/water samples differing only by their isotopic composition, the relative motion of the water to methanol molecules, i.e. their mutual dynamics, was determined at the nanoscale. The thus obtained nanoscopic mutual diffusion coefficient signals a significantly slower process than the single particle diffusion of either methanol or water in the system as well as their macroscopic mutual diffusion. The data do not provide any indication of microsegregation in this preeminent alcohol/water mixture; however, they do indicate the existence of long lived but dynamic molecular associates of water and methanol molecules. Analysis of the structural relaxation shows that the lifetime of molecular association through hydrogen bonding determines the fact that viscosity of the mixtures at intermediate concentrations is higher than that of both pure components.
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Affiliation(s)
- Yanqin Zhai
- Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Peng Luo
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Jackson Waller
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Jeffrey L Self
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, USA
| | - Leland W Harriger
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
| | - Y Z
- Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
| | - Antonio Faraone
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
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5
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Palomar R, Sesé G. Thermodynamic properties of a molecular dipolar liquid using the two-phase thermodynamic approach. Phys Chem Chem Phys 2021; 23:26524-26533. [PMID: 34807211 DOI: 10.1039/d1cp03246a] [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
A modified version of the original two-phase thermodynamic approach has been extended to evaluate the thermodynamic properties of molecular systems. Its basic assumption states that the density of states can be decomposed into solid-like and gas-like components. The solid part has been approximated by that of a set of harmonic oscillators, whereas a subset composed of rough hard spheres has been considered for the gas part. In this new approach, molecules have been modelled as rotating hard spheres that experience elastic collisions. The technique has been tested on a system made up of dipolar diatomic molecules, and it leads to very good results for total entropy, potential energy reference and heat capacity. Translation and rotation solid components of the overall spectra have been compared to the real part of the instantaneous normal mode vibrational densities of states. Similarities between them reinforce the validity of the two-phase thermodynamic approach.
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Affiliation(s)
- Ricardo Palomar
- Departament de Física, Universitat Politècnica de Catalunya, Campus Nord-Mòdul B4, c/Jordi Girona 1-3, 08034 Barcelona, Spain.
| | - Gemma Sesé
- Departament de Física, Universitat Politècnica de Catalunya, Campus Nord-Mòdul B4, c/Jordi Girona 1-3, 08034 Barcelona, Spain.
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6
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Su Z, Alavi S, Ripmeester JA, Wolosh G, Dias CL. Methane Clathrate Formation is Catalyzed and Kinetically Inhibited by the Same Molecule: Two Facets of Methanol. J Phys Chem B 2021; 125:4162-4168. [PMID: 33861613 DOI: 10.1021/acs.jpcb.1c01274] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Here, we perform molecular dynamics simulations to provide atomic-level insights into the dual roles of methanol in enhancing and delaying the rate of methane clathrate hydrate nucleation. Consistent with experiments, we find that methanol slows clathrate hydrate nucleation above 250 K but promotes clathrate formation at temperatures below 250 K. We show that this behavior can be rationalized by the unusual temperature dependence of the methane-methanol interaction in an aqueous solution, which emerges due to the hydrophobic effect. In addition to its antifreeze properties at temperatures above 250 K, methanol competes with water to interact with methane prior to the formation of clathrate nuclei. Below 250 K, methanol encourages water to occupy the space between methane molecules favoring clathrate formation and it may additionally promote water mobility.
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Affiliation(s)
- Zhaoqian Su
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, Bronx, New York 10461, United States
| | - Saman Alavi
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - John A Ripmeester
- National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada
| | - Gedaliah Wolosh
- New Jersey Institute of Technology, Academic and Research Computing Systems, University Heights, Newark, New Jersey 07102, United States
| | - Cristiano L Dias
- New Jersey Institute of Technology, Department of Physics, University Heights, Newark, New Jersey 07102, United States
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7
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Servis MJ, Piechowicz M, Skanthakumar S, Soderholm L. Molecular-scale origins of solution nanostructure and excess thermodynamic properties in a water/amphiphile mixture. Phys Chem Chem Phys 2021; 23:8880-8890. [PMID: 33876047 DOI: 10.1039/d1cp00082a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The molecular and nanoscale origins of nonideality in excess thermodynamic properties are essential to understanding cosolvent mixtures, yet they remain challenging to determine. Here, we consider a binary mixture of water and an amphiphile, N,N,N',N'-tetramethylmalonamide (TMMA), which is characterized by strong hydrogen bonding between the two components and no hydrogen bonding between amphiphiles. Using molecular dynamics simulation, validated with excess volume measurements and X-ray scattering, we identify three distinct solution regimes across the composition range of the binary mixture and find that the transition between two of these regimes, marked by the water percolation threshold, is closely correlated with minima in the excess volume and excess enthalpy. Structural analysis of the simulations reveals an interplay between local interactions and solution nanostructure, determined by the relative strength of the water-water and water-amphiphile hydrogen bonding interactions. By comparison with other amphiphiles, such as linear alcohols, the relative strength of like and unlike interactions between water and amphiphile affects the relationship between thermodynamics and structural regimes. This provides insight into how molecular forces of mutual solvation interact across length scales and how they manifest in excess thermodynamic properties.
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Affiliation(s)
- Michael J Servis
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL, 60439, USA.
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8
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Pethes I, Pusztai L, Ohara K, Kohara S, Darpentigny J, Temleitner L. Temperature-dependent structure of methanol-water mixtures on cooling: X-ray and neutron diffraction and molecular dynamics simulations. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.113664] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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9
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Li S, Pokuri BSS, Ryno SM, Nkansah A, De'Vine C, Ganapathysubramanian B, Risko C. Determination of the Free Energies of Mixing of Organic Solutions through a Combined Molecular Dynamics and Bayesian Statistics Approach. J Chem Inf Model 2020; 60:1424-1431. [PMID: 31935097 DOI: 10.1021/acs.jcim.9b01113] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
As new generations of thin-film semiconductors are moving toward solution-based processing, the development of printing formulations will require information pertaining to the free energies of mixing of complex mixtures. From the standpoint of in silico material design, this move necessitates the development of methods that can accurately and quickly evaluate these formulations in order to maximize processing speed and reproducibility. Here, we make use of molecular dynamics (MD) simulations, in combination with the two-phase thermodynamic (2PT) model, to explore the free energy of mixing surfaces for a series of halogenated solvents and high-boiling point solvent additives used in the development of thin-film organic semiconductors. Although the combined methods generally show good agreement with available experimental data, the computational cost to traverse the free-energy landscape is considerable. Hence, we demonstrate how a Bayesian optimization scheme, coupled with the MD and 2PT approaches, can drastically reduce the number of simulations required, in turn shrinking both the computational cost and time.
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Affiliation(s)
- Shi Li
- Department of Chemistry & Center for Applied Energy Research (CAER), University of Kentucky, Lexington, Kentucky 40506, United States
| | | | - Sean M Ryno
- Department of Chemistry & Center for Applied Energy Research (CAER), University of Kentucky, Lexington, Kentucky 40506, United States
| | - Asare Nkansah
- Department of Chemistry & Center for Applied Energy Research (CAER), University of Kentucky, Lexington, Kentucky 40506, United States
| | - Camron De'Vine
- Department of Chemistry & Center for Applied Energy Research (CAER), University of Kentucky, Lexington, Kentucky 40506, United States
| | | | - Chad Risko
- Department of Chemistry & Center for Applied Energy Research (CAER), University of Kentucky, Lexington, Kentucky 40506, United States
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10
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Zhang X, Wang Z, Chen Z, Li H, Zhang L, Ye J, Zhang Q, Zhuang W. Molecular Mechanism of Water Reorientation Dynamics in Dimethyl Sulfoxide Aqueous Mixtures. J Phys Chem B 2020; 124:1806-1816. [PMID: 32022564 DOI: 10.1021/acs.jpcb.0c00717] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nonmonotonic composition dependence is often observed for numerous properties in the aqueous mixtures of small amphiphilic molecules. The molecular picture underlying this structure-activity relationship, however, remains largely elusive. We herein studied water reorientation dynamics in the aqueous mixture of dimethyl sulfoxide (DMSO), which has a significant nonmonotonic composition dependence, using molecular dynamic simulation and an extended molecular jump model. The analysis indicates that this nonideal behavior is driven by the collective frame diffusion component of water reorientation, which decelerates in the water-rich regime because of the strengthened hydrogen bonds and accelerates in the water-poor regime as the hydrogen bonding network is broken into smaller aggregates. The current work therefore connects the microheterogeneity in the solvation structure of DMSO-water with its nonmonotonic hydration dynamics and sheds new light on how microsegregation leads to the multiscale hydration nonideality in general.
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Affiliation(s)
- Xia Zhang
- College of Chemistry and Materials Science, Inner Mongolia University for Nationlities, Tongliao Inner Mongolia 028043, China
| | - Zhangtao Wang
- College of Chemistry and Chemical Engineering, Bohai University, Jinzhou, Liaoning 121013, China
| | - Zhening Chen
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 35000, China
| | - Hui Li
- College of Chemistry and Chemical Engineering, Bohai University, Jinzhou, Liaoning 121013, China
| | - Lu Zhang
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 35000, China
| | - Jinting Ye
- College of Chemistry and Materials Science, Inner Mongolia University for Nationlities, Tongliao Inner Mongolia 028043, China
| | - Qiang Zhang
- College of Chemistry and Materials Science, Inner Mongolia University for Nationlities, Tongliao Inner Mongolia 028043, China
| | - Wei Zhuang
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 35000, China
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11
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Li F, Wang Y, Men Z, Sun C. Exploring the hydrogen bond kinetics of methanol–water solutions using Raman scattering. Phys Chem Chem Phys 2020; 22:26000-26004. [DOI: 10.1039/d0cp04295a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Stimulated Raman scattering was used to clearly show the hydrogen bond kinetics of water–methanol mixed solutions.
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Affiliation(s)
- Fabing Li
- Coherent Light and Atomic and Molecular Spectroscopy Laboratory
- College of Physics
- Jilin University
- Changchun 130012
- China
| | - Ying Wang
- Coherent Light and Atomic and Molecular Spectroscopy Laboratory
- College of Physics
- Jilin University
- Changchun 130012
- China
| | - Zhiwei Men
- Coherent Light and Atomic and Molecular Spectroscopy Laboratory
- College of Physics
- Jilin University
- Changchun 130012
- China
| | - Chenglin Sun
- Key Laboratory of Physics and Technology for Advanced Batteries
- College of Physics
- Jilin University
- Changchun 130012
- China
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12
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Tiwari A, Honingh C, Ensing B. Accurate calculation of zero point energy from molecular dynamics simulations of liquids and their mixtures. J Chem Phys 2019; 151:244124. [PMID: 31893925 DOI: 10.1063/1.5131145] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The two-phase thermodynamic (2PT) method is used to compute the zero point energy (ZPE) of several liquids and their mixtures. The 2PT method uses the density of states (DoS), which is computed from the velocity autocorrelation (VAC) function obtained from a short classical molecular dynamics trajectory. By partitioning the VAC and the DoS of a fluid into solid and gaslike components, quantum mechanical corrections to thermodynamical properties can be computed. The ZPE is obtained by combining the partition function of the quantum harmonic oscillator with the vibrational part of the solidlike DoS. The resulting ZPE is found to be in excellent agreement with both experimental and ab initio results. Solvent effects such as hydrogen bonding and polarization can be included by the utilization of ab initio density functional theory based molecular dynamics simulations. It is found that these effects significantly influence the DoS of water molecules. The obtained results demonstrate that the 2PT model is a powerful method for efficient ZPE calculations, in particular, to account for solvent effects and polarization.
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Affiliation(s)
- A Tiwari
- Van't Hoff Institute for Molecular Sciences, Universiteit van Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - C Honingh
- Van't Hoff Institute for Molecular Sciences, Universiteit van Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - B Ensing
- Van't Hoff Institute for Molecular Sciences, Universiteit van Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
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13
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Das Mahanta D, Islam SI, Choudhury S, Das DK, Mitra RK, Barman A. Contrasting hydration dynamics in DME and DMSO aqueous solutions: A combined optical pump-probe and GHz-THz dielectric relaxation investigation. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.111194] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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14
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Rosenberger D, Sanyal T, Shell MS, van der Vegt NFA. Transferability of Local Density-Assisted Implicit Solvation Models for Homogeneous Fluid Mixtures. J Chem Theory Comput 2019; 15:2881-2895. [PMID: 30995034 DOI: 10.1021/acs.jctc.8b01170] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The application of bottom-up coarse grained (CG) models to study the equilibrium mixing behavior of liquids is rather challenging, since these models can be significantly influenced by the density or the concentration of the state chosen during parametrization. This dependency leads to low transferability in density/concentration space and has been one of the major limitations in bottom-up coarse graining. Recent approaches proposed to tackle this shortcoming range from the addition of thermodynamic constraints, to an extended ensemble parametrization, to the addition of supplementary terms to the system's Hamiltonian. To study fluid phase equilibria with bottom-up CG models, the application of local density (LD) potentials appears to be a promising approach, as shown in previous work by Sanyal and Shell [T. Sanyal, M. S. Shell, J. Phys. Chem. B, 2018, 122, 5678]. Here, we want to further explore this method and test its ability to model a system which contains structural inhomogeneities only on the molecular scale, namely, solutions of methanol and water. We find that a water-water LD potential improves the transferability of an implicit-methanol CG model toward high water concentration. Conversely, a methanol-methanol LD potential does not significantly improve the transferability of an implicit-water CG model toward high methanol concentration. These differences appear due to the presence of cooperative interactions in water at high concentrations that the LD potentials can capture. In addition, we compare two different approaches to derive our CG models, namely, relative entropy optimization and the Inverse Monte Carlo method, and formally demonstrate under which analytical and numerical assumptions these two methods yield equivalent results.
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Affiliation(s)
- David Rosenberger
- Eduard Zintl Institut für Anorganische und Physikalische Chemie , Technische Universität Darmstadt , Darmstadt , Germany
| | - Tanmoy Sanyal
- Department of Chemical Engineering , University of California Santa Barbara , Santa Barbara , California 93106 , United States
| | - M Scott Shell
- Department of Chemical Engineering , University of California Santa Barbara , Santa Barbara , California 93106 , United States
| | - Nico F A van der Vegt
- Eduard Zintl Institut für Anorganische und Physikalische Chemie , Technische Universität Darmstadt , Darmstadt , Germany
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15
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Mosaddeghi H, Alavi S, Kowsari MH, Najafi B, Az'hari S, Afshar Y. Molecular dynamics simulations of nano-confined methanol and methanol-water mixtures between infinite graphite plates: Structure and dynamics. J Chem Phys 2019; 150:144510. [PMID: 30981262 DOI: 10.1063/1.5088030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Molecular dynamics simulations are used to investigate microscopic structures and dynamics of methanol and methanol-water binary mixture films confined between hydrophobic infinite parallel graphite plate slits with widths, H, in the range of 7-20 Å at 300 K. The initial geometric densities of the liquids were chosen to be the same as bulk methanol at the same temperature. For the two narrowest slit widths, two smaller initial densities were also considered. For the nano-confined system with H = 7 Å and high pressure, a solid-like hexagonal arrangement of methanol molecules arranged perpendicular to the plates is observed which reflects the closest packing of the molecules and partially mirrors the structure of the underlying graphite structure. At lower pressures and for larger slit widths, in the contact layer, the methanol molecules prefer having the C-O bond oriented parallel to the walls. Layered structures of methanol parallel to the wall were observed, with contact layers and additional numbers of central layers depending on the particular slit width. For methanol-water mixtures, simulations of solutions with different composition were performed between infinite graphite slits with H = 10 and 20 Å at 300 K. For the nanoslit with H = 10 Å, in the solution mixtures, three layers of molecules form, but for all mole fractions of methanol, methanol molecules are excluded from the central fluid layer. In the nanopore with H = 20 Å, more than three fluid layers are formed and methanol concentrations are enhanced near the confining plates walls compared to the average solution stoichiometry. The self-diffusion coefficients of methanol and water molecules in the solution show strong dependence on the solution concentration. The solution mole fractions with minimal diffusivity are the same in confined and non-confined bulk methanol-water mixtures.
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Affiliation(s)
- Hamid Mosaddeghi
- Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran
| | - Saman Alavi
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Mohammad H Kowsari
- Department of Chemistry and Center for Research in Climate Change and Global Warming (CRCC), Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran
| | - Bijan Najafi
- Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran
| | - Sara Az'hari
- Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran
| | - Yaser Afshar
- Department of Aerospace Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
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16
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Basařová P, Pišlová J, Mills J, Orvalho S. Influence of molecular structure of alcohol-water mixtures on bubble behaviour and bubble surface mobility. Chem Eng Sci 2018. [DOI: 10.1016/j.ces.2018.07.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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17
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Kuroki N, Mori H. Applicability of effective fragment potential version 2 – Molecular dynamics (EFP2-MD) simulations for predicting excess properties of mixed solvents. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2018.01.042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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18
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Elewa M, Maltar-Strmečki N, Said MM, El Shihawy HA, El-Sadek M, Frank J, Drescher S, Drescher M, Mäder K, Hinderberger D, Imming P. Synthesis and EPR-spectroscopic characterization of the perchlorotriarylmethyl tricarboxylic acid radical (PTMTC) and its 13C labelled analogue (13C-PTMTC). Phys Chem Chem Phys 2018; 19:6688-6697. [PMID: 28210718 DOI: 10.1039/c6cp07200c] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A hydrophilic tris(tetrachlorotriaryl)methyl (tetrachloro-TAM) radical labelled 50% with 13C at the central carbon atom was prepared. The mixture of isotopologue radicals was characterised by continuous wave and pulsed X-band electron paramagnetic spectroscopy (EPS). For the pharmaceutical and medical applications planned, the quantitative influence of oxygen, viscosity, temperature and pH on EPR line widths was studied in aqueous buffer, DMSO, water-methanol and water-glycerol mixtures. Under in vivo conditions, pH can be disregarded. There is a clear oxygen dependence of the width of the 12C isotopologue single EPR line in aqueous solutions while changes in rotational motion (viscosity) are observable only in the doublet lines of the central carbon of the 13C isotopologue. The tetrachloro-TAM proved to be very stable as a solid. Its thermal decay was determined quantitatively by thermal annealing. Towards ascorbic acid as a reducing agent and towards an oocyte cell extract it had a half-life of approx. 60 and 10 min. Thus for in vivo applications, 50% 13C tetrachloro-TAMs are suitable for selective and simultaneous oxygen and macroviscosity measurements in a formulation, e.g. nanocapsules.
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Affiliation(s)
- Marwa Elewa
- Institut für Pharmazie, Martin-Luther-Universität Halle-Wittenberg, Wolfgang-Langenbeck-Str. 4, 06120 Halle, Germany. and Faculty of Pharmacy, Suez Canal University, P.O. 41522, Ismailia, Egypt
| | - Nadica Maltar-Strmečki
- Institut für Chemie, Physikalische Chemie, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle, Germany.
| | - Mohamed M Said
- Faculty of Pharmacy, Suez Canal University, P.O. 41522, Ismailia, Egypt
| | | | | | - Juliane Frank
- Institut für Pharmazie, Martin-Luther-Universität Halle-Wittenberg, Wolfgang-Langenbeck-Str. 4, 06120 Halle, Germany.
| | - Simon Drescher
- Institut für Pharmazie, Martin-Luther-Universität Halle-Wittenberg, Wolfgang-Langenbeck-Str. 4, 06120 Halle, Germany.
| | - Malte Drescher
- Department of Chemistry and Konstanz Research School Chemical Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Karsten Mäder
- Institut für Pharmazie, Martin-Luther-Universität Halle-Wittenberg, Wolfgang-Langenbeck-Str. 4, 06120 Halle, Germany.
| | - Dariush Hinderberger
- Institut für Chemie, Physikalische Chemie, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle, Germany.
| | - Peter Imming
- Institut für Pharmazie, Martin-Luther-Universität Halle-Wittenberg, Wolfgang-Langenbeck-Str. 4, 06120 Halle, Germany.
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19
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Zhang X, Zhang L, Jin T, Zhang Q, Zhuang W. Cosolvent effect on the dynamics of water in aqueous binary mixtures. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1424958] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Xia Zhang
- Department of Chemistry, Bohai University, Jinzhou, China
| | - Lu Zhang
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, China
| | - Tan Jin
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, China
| | - Qiang Zhang
- Department of Chemistry, Bohai University, Jinzhou, China
| | - Wei Zhuang
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, China
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20
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Kohns M, Horsch M, Hasse H. Activity coefficients from molecular simulations using the OPAS method. J Chem Phys 2017; 147:144108. [DOI: 10.1063/1.4991498] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Affiliation(s)
- Maximilian Kohns
- Laboratory of Engineering Thermodynamics, University of Kaiserslautern, Erwin-Schrödinger Str. 44, D-67663 Kaiserslautern, Germany
| | - Martin Horsch
- Laboratory of Engineering Thermodynamics, University of Kaiserslautern, Erwin-Schrödinger Str. 44, D-67663 Kaiserslautern, Germany
| | - Hans Hasse
- Laboratory of Engineering Thermodynamics, University of Kaiserslautern, Erwin-Schrödinger Str. 44, D-67663 Kaiserslautern, Germany
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21
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Caro MA, Lopez-Acevedo O, Laurila T. Redox Potentials from Ab Initio Molecular Dynamics and Explicit Entropy Calculations: Application to Transition Metals in Aqueous Solution. J Chem Theory Comput 2017; 13:3432-3441. [DOI: 10.1021/acs.jctc.7b00314] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Miguel A. Caro
- Department
of Electrical Engineering and Automation, Aalto University, 02150 Espoo, Finland
- COMP
Centre of Excellence in Computational Nanoscience, Department of Applied
Physics, Aalto University, Espoo, 02150Finland
| | - Olga Lopez-Acevedo
- COMP
Centre of Excellence in Computational Nanoscience, Department of Applied
Physics, Aalto University, Espoo, 02150Finland
- Departamento
de Ciencias Básicas, Universidad de Medellín, 050026 Medellín, Colombia
| | - Tomi Laurila
- Department
of Electrical Engineering and Automation, Aalto University, 02150 Espoo, Finland
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22
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Caro MA, Laurila T, Lopez-Acevedo O. Accurate schemes for calculation of thermodynamic properties of liquid mixtures from molecular dynamics simulations. J Chem Phys 2017; 145:244504. [PMID: 28049340 DOI: 10.1063/1.4973001] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We explore different schemes for improved accuracy of entropy calculations in aqueous liquid mixtures from molecular dynamics (MD) simulations. We build upon the two-phase thermodynamic (2PT) model of Lin et al. [J. Chem. Phys. 119, 11792 (2003)] and explore new ways to obtain the partition between the gas-like and solid-like parts of the density of states, as well as the effect of the chosen ideal "combinatorial" entropy of mixing, both of which have a large impact on the results. We also propose a first-order correction to the issue of kinetic energy transfer between degrees of freedom (DoF). This problem arises when the effective temperatures of translational, rotational, and vibrational DoF are not equal, either due to poor equilibration or reduced system size/time sampling, which are typical problems for ab initio MD. The new scheme enables improved convergence of the results with respect to configurational sampling, by up to one order of magnitude, for short MD runs. To ensure a meaningful assessment, we perform MD simulations of liquid mixtures of water with several other molecules of varying sizes: methanol, acetonitrile, N, N-dimethylformamide, and n-butanol. Our analysis shows that results in excellent agreement with experiment can be obtained with little computational effort for some systems. However, the ability of the 2PT method to succeed in these calculations is strongly influenced by the choice of force field, the fluidicity (hard-sphere) formalism employed to obtain the solid/gas partition, and the assumed combinatorial entropy of mixing. We tested two popular force fields, GAFF and OPLS with SPC/E water. For the mixtures studied, the GAFF force field seems to perform as a slightly better "all-around" force field when compared to OPLS+SPC/E.
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Affiliation(s)
- Miguel A Caro
- COMP Centre of Excellence in Computational Nanoscience, Department of Applied Physics, Aalto University, Espoo, Finland
| | - Tomi Laurila
- Department of Electrical Engineering and Automation, Aalto University, Espoo, Finland
| | - Olga Lopez-Acevedo
- COMP Centre of Excellence in Computational Nanoscience, Department of Applied Physics, Aalto University, Espoo, Finland
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23
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Sulaiman MI, Yang S, Ellis AM. Infrared Spectroscopy of Methanol and Methanol/Water Clusters in Helium Nanodroplets: The OH Stretching Region. J Phys Chem A 2017; 121:771-776. [DOI: 10.1021/acs.jpca.6b11170] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Media I. Sulaiman
- Department of Chemistry, University of Leicester, University Road, Leicester, LE1 7RH, U.K
| | - Shengfu Yang
- Department of Chemistry, University of Leicester, University Road, Leicester, LE1 7RH, U.K
| | - Andrew M. Ellis
- Department of Chemistry, University of Leicester, University Road, Leicester, LE1 7RH, U.K
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24
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Donaldson SH, Jahnke JP, Messinger RJ, Östlund Å, Uhrig D, Israelachvili JN, Chmelka BF. Correlated Diffusivities, Solubilities, and Hydrophobic Interactions in Ternary Polydimethylsiloxane–Water–Tetrahydrofuran Mixtures. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b01514] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Stephen H. Donaldson
- Department
of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, California 93106-5080, United States
- Departement
de Physique, Ecole Normale Supérieure/PSL Research University, CNRS, 24 rue Lhomond, 75005 Paris, France
| | - Justin P. Jahnke
- Department
of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, California 93106-5080, United States
| | - Robert J. Messinger
- Department
of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, California 93106-5080, United States
| | - Åsa Östlund
- Department
of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, California 93106-5080, United States
| | - David Uhrig
- Center
for Nanophase Materials, Sciences Division, Oak Ridge National Laboratory, P.O.
Box 2008, Oak Ridge, Tennessee 37831, United States
| | - Jacob N. Israelachvili
- Department
of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, California 93106-5080, United States
| | - Bradley F. Chmelka
- Department
of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, California 93106-5080, United States
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25
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Lam RK, Smith JW, Saykally RJ. Communication: Hydrogen bonding interactions in water-alcohol mixtures from X-ray absorption spectroscopy. J Chem Phys 2016; 144:191103. [DOI: 10.1063/1.4951010] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Royce K. Lam
- Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Jacob W. Smith
- Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Richard J. Saykally
- Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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26
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INDRA SANDIPA, BISWAS RANJIT. Are N-methyl groups of Tetramethylurea (TMU) Hydrophobic? A composition and temperature-dependent fluorescence spectroscopic investigation of TMU/water binary mixtures. J CHEM SCI 2016. [DOI: 10.1007/s12039-016-1072-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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27
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Soetens JC, Bopp PA. Water-Methanol Mixtures: Simulations of Mixing Properties over the Entire Range of Mole Fractions. J Phys Chem B 2015; 119:8593-9. [PMID: 26082996 DOI: 10.1021/acs.jpcb.5b03344] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Numerous experimental and theoretical investigations have been devoted to the hydrogen bond in pure liquids and mixtures. Among the different theoretical approaches, molecular dynamics (MD) simulations are predominant in obtaining detailed information, on the molecular level, simultaneously on the structure and the dynamics. Water and methanol are the two most prominent hydrogen-bonded liquids, and they and their mixtures have consequently been the subject of many studies; we revisit here the problem of the mixtures. An important first step is to check whether a classical potential model, the components of which are deemed to be satisfactory for the pure liquids, is able to reproduce the known thermodynamic excess properties of the mixtures sufficiently well. We have used the available BJH (water) and PHH (methanol) flexible models because they are by construction mutually compatible and also well suited to study, in a second step, some dynamic property characteristic of hydrogen-bonded liquids. In this article we show that these models, after a slight reparametrization for use in NpT simulations, reproduce the essential features of the excess mixing and molar properties of water-methanol mixtures. Furthermore, in the pure liquids, the agreement of the radial distribution functions with experiment remains as satisfactory as before. Similarly, the translation self-diffusion coefficients D are modified by less than 10%. In the mixtures, they evolve nonmonotonously as a function of mole fraction.
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Affiliation(s)
- Jean-Christophe Soetens
- Institut des Sciences Moléculaires, UMR CNRS no. 5255, and Department of Chemistry, Université de Bordeaux, 351 Cours de la Libération, 33405 Talence, France
| | - Philippe A Bopp
- Institut des Sciences Moléculaires, UMR CNRS no. 5255, and Department of Chemistry, Université de Bordeaux, 351 Cours de la Libération, 33405 Talence, France
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28
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Fortunelli A, Goddard WA, Sementa L, Barcaro G. Optimizing the oxygen evolution reaction for electrochemical water oxidation by tuning solvent properties. NANOSCALE 2015; 7:4514-4521. [PMID: 25682836 DOI: 10.1039/c4nr07277d] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Electrochemical water-based energy cycles provide a most promising alternative to fossil-fuel sources of energy. However, current electrocatalysts are not adequate (high overpotential, lack of selectivity toward O2 production, catalyst degradation). We propose here mechanistic guidelines for experimental examination of modified catalysts based on the dependence of kinetic rates on the solvent dielectric constant. To illustrate the procedure we consider the fcc(111) platinum surface and show that the individual steps for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) change systematically with the polarizability of the medium. Thus changing this environmental variable can be used to tune the rate determining steps and the barriers, providing a means for screening and validating new systems to optimize the rate determining steps for the ORR and OER reaction pathways.
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Affiliation(s)
- Alessandro Fortunelli
- CNR-ICCOM and IPCF, Consiglio Nazionale delle Ricerche, via Giuseppe Moruzzi 1, 56124, Pisa, Italy
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29
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Hsieh WP, Chien YH. High pressure Raman spectroscopy of H2O-CH3OH mixtures. Sci Rep 2015; 5:8532. [PMID: 25704667 PMCID: PMC4336930 DOI: 10.1038/srep08532] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 01/23/2015] [Indexed: 02/02/2023] Open
Abstract
Complex intra-molecular interactions and the hydrogen-bonding network in H2O-volatile mixtures play critical roles in many dynamics processes in physical chemistry, biology, and Earth and planetary sciences. We used high pressure Raman spectroscopy to study the pressure evolution of vibrational frequencies and bonding behavior in H2O-CH3OH mixtures. We found that the presence of low CH3OH content in H2O increases the transition pressure where water crystallizes to ice VI, but does not significantly change the pressure where ice VI transforms to ice VII. Furthermore, the stiffening rates of C-H stretching frequencies dω/dP in CH3OH significantly decrease upon the crystallization of water, and the softening rates of the O-H stretching frequencies of ice VII are suppressed over a narrow pressure range, after which the frequencies of these modes shift with pressure in ways similar to pure CH3OH and ice VII, respectively. Such complex pressure evolution of Raman frequencies along with pronounced variations in Raman intensities of CH3OH within the sample, and the hysteresis of the water-ice VI phase transition suggest pressure-induced segregation of low content CH3OH from ice VII. These findings indicate the significant influence of volatiles on the crystallization of sub-surface ocean and thermal evolution within large icy planets and satellites.
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Affiliation(s)
- Wen-Pin Hsieh
- Institute of Earth Sciences, Academia Sinica, Nankang, Taipei. 11529, Taiwan
| | - Yu-Hsiang Chien
- Institute of Earth Sciences, Academia Sinica, Nankang, Taipei. 11529, Taiwan
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30
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Matisz G, Kelterer AM, Fabian WMF, Kunsági-Máté S. Structural properties of methanol–water binary mixtures within the quantum cluster equilibrium model. Phys Chem Chem Phys 2015; 17:8467-79. [DOI: 10.1039/c4cp05836d] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The Quantum Cluster Equilibrium (QCE) method computes cluster distributions and thermodynamic properties of binary methanol–water mixtures in agreement with experiments.
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Affiliation(s)
- G. Matisz
- Department of General and Physical Chemistry
- University of Pécs
- 7624 Pécs
- Hungary
- János Szentágothai Research Center
| | - A.-M. Kelterer
- Institute of Physical and Theoretical Chemistry
- Graz University of Technology
- NAWI Graz
- 8010 Graz
- Austria
| | - W. M. F. Fabian
- Institute of Chemistry
- University of Graz
- NAWI Graz
- 8010 Graz
- Austria
| | - S. Kunsági-Máté
- Department of General and Physical Chemistry
- University of Pécs
- 7624 Pécs
- Hungary
- János Szentágothai Research Center
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31
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Benay G, Wipff G. Ammonium Recognition by 18-Crown-6 in Different Solutions and at an Aqueous Interface: A Simulation Study. J Phys Chem B 2014; 118:13913-29. [DOI: 10.1021/jp508379w] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- G. Benay
- Laboratoire MSM, UMR 7177, Institut de Chimie, 1 rue B. Pascal, 67000 Strasbourg, France
| | - G. Wipff
- Laboratoire MSM, UMR 7177, Institut de Chimie, 1 rue B. Pascal, 67000 Strasbourg, France
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32
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Frasch DM, Spiegel DR. Experiments on tracer diffusion in aqueous and non-aqueous solvent combinations. J Chem Phys 2014; 141:124507. [PMID: 25273451 DOI: 10.1063/1.4896303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Forced Rayleigh scattering is used to study the tracer diffusion of an azobenzene in binary combinations of polar solvents, including water. In the absence of water, the tracer diffusion coefficient D in the mixture lies between the diffusion coefficients within the pure solvents, on a curve that is reasonably close to the prediction of free-volume theory. If water is present, on the other hand, the diffusion coefficient displays a minimum that is less than the smaller of the two pure-solvent values. We attempt to understand the different behavior in water by concentrating on the fairly hydrophobic nature of the solute, leading to a first solvent shell that is hydrophobic on the inside and hydrophilic on the outside. We also believe that clusters of amphiphiles explain the observation that, in aqueous combinations, D is nearly constant above a certain amphiphile mole fraction.
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Affiliation(s)
- Duncan M Frasch
- Department of Physics and Astronomy, Trinity University, San Antonio, Texas 78212, USA
| | - Daniel R Spiegel
- Department of Physics and Astronomy, Trinity University, San Antonio, Texas 78212, USA
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33
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Fortunelli A, Goddard WA, Sha Y, Yu TH, Sementa L, Barcaro G, Andreussi O. Dramatic increase in the oxygen reduction reaction for platinum cathodes from tuning the solvent dielectric constant. Angew Chem Int Ed Engl 2014; 53:6669-72. [PMID: 24828005 DOI: 10.1002/anie.201403264] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Indexed: 11/08/2022]
Abstract
Hydrogen fuel cells (FC) are considered essential for a sustainable economy based on carbon-free energy sources, but a major impediment are the costs. First-principles quantum mechanics (density functional theory including solvation) is used to predict how the energies and barriers for the mechanistic steps of the oxygen reduction reaction (ORR) over the fcc(111) platinum surface depend on the dielectric constant of the solvent. The ORR kinetics can be strongly accelerated by decreasing the effective medium polarizability from the high value it has in water. Possible ways to realize this experimentally are suggested. The calculated volcano structure for the dependence of rate on solvent polarization is considered to be general, and should be observed in other electrochemical systems.
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Affiliation(s)
- Alessandro Fortunelli
- CNR-ICCOM and IPCF, Consiglio Nazionale delle Ricerche via Giuseppe Moruzzi 1, 56124 Pisa (Italy); Materials and Process Simulation Center, California Institute of Technology, MC 139-74, Pasadena, CA 91125 (USA). ,
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34
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Pascal TA, Goddard WA. Interfacial Thermodynamics of Water and Six Other Liquid Solvents. J Phys Chem B 2014; 118:5943-56. [DOI: 10.1021/jp410861h] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Tod A. Pascal
- Materials and Process Simulation
Center, California Institute of Technology, Pasadena, California 91125, United States
| | - William A. Goddard
- Materials and Process Simulation
Center, California Institute of Technology, Pasadena, California 91125, United States
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35
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Fortunelli A, Goddard WA, Sha Y, Yu TH, Sementa L, Barcaro G, Andreussi O. Dramatic Increase in the Oxygen Reduction Reaction for Platinum Cathodes from Tuning the Solvent Dielectric Constant. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201403264] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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36
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Scherzinger C, Schwarz A, Bardow A, Leonhard K, Richtering W. Cononsolvency of poly-N-isopropyl acrylamide (PNIPAM): Microgels versus linear chains and macrogels. Curr Opin Colloid Interface Sci 2014. [DOI: 10.1016/j.cocis.2014.03.011] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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37
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Lai PK, Lin ST. Rapid determination of entropy for flexible molecules in condensed phase from the two-phase thermodynamic model. RSC Adv 2014. [DOI: 10.1039/c3ra47071g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
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38
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Cuellar KA, Munroe KL, Magers DH, Hammer NI. Noncovalent Interactions in Microsolvated Networks of Trimethylamine N-Oxide. J Phys Chem B 2013; 118:449-59. [DOI: 10.1021/jp408659n] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kristina A. Cuellar
- Department
of Chemistry and Biochemistry, University of Mississippi, P.O. Box 1848, University, Mississippi 38655, United States
| | - Katherine L. Munroe
- Department
of Chemistry and Biochemistry, Mississippi College, P.O. Box 4036, Clinton, Mississippi 39058, United States
| | - David H. Magers
- Department
of Chemistry and Biochemistry, Mississippi College, P.O. Box 4036, Clinton, Mississippi 39058, United States
| | - Nathan I. Hammer
- Department
of Chemistry and Biochemistry, University of Mississippi, P.O. Box 1848, University, Mississippi 38655, United States
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39
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Bertrand CE, Chiang WS, Tyagi M, Chen SH. Low-temperature water dynamics in an aqueous methanol solution. J Chem Phys 2013; 139:014505. [PMID: 23822312 DOI: 10.1063/1.4812286] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
An aqueous methanol solution (x(MeOH) = 0.30) has been studied by quasielastic neutron scattering. The single-particle water dynamics were effectively isolated by employing deuterated methanol. A smooth dynamic transition to a sub-Arrhenius temperature dependence has been observed in the relaxation times. We associate this behavior with the formation of small crystallites in the system. These findings are compared with molecular dynamics simulations and previous nuclear magnetic resonance measurements. We discuss possible dynamic signatures of structuring in the mixture.
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Affiliation(s)
- C E Bertrand
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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40
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Methanol incorporation in clathrate hydrates and the implications for oil and gas pipeline flow assurance and icy planetary bodies. Proc Natl Acad Sci U S A 2013; 110:8437-42. [PMID: 23661058 DOI: 10.1073/pnas.1302812110] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
One of the best-known uses of methanol is as antifreeze. Methanol is used in large quantities in industrial applications to prevent methane clathrate hydrate blockages from forming in oil and gas pipelines. Methanol is also assigned a major role as antifreeze in giving icy planetary bodies (e.g., Titan) a liquid subsurface ocean and/or an atmosphere containing significant quantities of methane. In this work, we reveal a previously unverified role for methanol as a guest in clathrate hydrate cages. X-ray diffraction (XRD) and NMR experiments showed that at temperatures near 273 K, methanol is incorporated in the hydrate lattice along with other guest molecules. The amount of included methanol depends on the preparative method used. For instance, single-crystal XRD shows that at low temperatures, the methanol molecules are hydrogen-bonded in 4.4% of the small cages of tetrahydrofuran cubic structure II hydrate. At higher temperatures, NMR spectroscopy reveals a number of methanol species incorporated in hydrocarbon hydrate lattices. At temperatures characteristic of icy planetary bodies, vapor deposits of methanol, water, and methane or xenon show that the presence of methanol accelerates hydrate formation on annealing and that there is unusually complex phase behavior as revealed by powder XRD and NMR spectroscopy. The presence of cubic structure I hydrate was confirmed and a unique hydrate phase was postulated to account for the data. Molecular dynamics calculations confirmed the possibility of methanol incorporation into the hydrate lattice and show that methanol can favorably replace a number of methane guests.
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Benson SP, Pleiss J. Incomplete mixing versus clathrate-like structures: A molecular view on hydrophobicity in methanol–water mixtures. J Mol Model 2013; 19:3427-36. [DOI: 10.1007/s00894-013-1857-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 04/16/2013] [Indexed: 10/26/2022]
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