1
|
Stracke K, Evans JD. The use of collective variables and enhanced sampling in the simulations of existing and emerging microporous materials. NANOSCALE 2024. [PMID: 38647659 DOI: 10.1039/d4nr01024h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
Microporous materials, including zeolites, metal-organic frameworks, and cage compounds, offer diverse functionalities due to their unique dynamics and guest confinement properties. These materials play a significant role in separation, catalysis, and sensing, but their complexity hinders exploration using traditional atomistic simulations. This review explores collective variables (CVs) paired with enhanced sampling as a powerful approach to enable efficient investigation of key features in microporous materials. We highlight successful applications of CVs in studying adsorption, diffusion, phase transitions, and mechanical properties, demonstrating their crucial role in guiding material design and optimisation. The future of CVs lies in integration with techniques like machine learning, allowing for enhanced efficiency and accuracy. By tailoring CVs to specific materials and developing multi-scale approaches we can further unlock the intricacies of these fascinating materials. Simulations are a cornerstone in unravelling the complexities of microporous materials and are crucial for our future understanding.
Collapse
Affiliation(s)
- Konstantin Stracke
- School of Physics, Chemistry and Earth Science, The University of Adelaide, 5005 Australia.
| | - Jack D Evans
- School of Physics, Chemistry and Earth Science, The University of Adelaide, 5005 Australia.
| |
Collapse
|
2
|
Wang J, Xie SJ. The influence of force fields on the structure and dynamics of water confined in ZIF-8 from atomistic simulations. Phys Chem Chem Phys 2023; 25:23100-23110. [PMID: 37602670 DOI: 10.1039/d3cp02075d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/22/2023]
Abstract
The complexity of modeling flexible crystals, such as ZIF-8, mainly stems from the handling of intramolecular interactions. Numerous force fields have been proposed in the literature to describe the interactions between atoms in ZIF-8. We employ seven force fields to examine the structure and dynamic behavior of water molecules confined in ZIF-8, with the aim of investigating the impact of force fields on simulation results. Various structural characterization methods consistently indicate that the choice of different force fields has quantitative effects but no qualitative effects on the structural characteristics of confined water. Additionally, the force fields do not impact the qualitative description of the diffusion mechanism. Both mean-square displacement and van Hove autocorrelation function reveal two characteristic movements of water molecules diffusing in ZIF-8: a short-time intra-cavity hopping process and a long-time inter-cavity hopping process. However, the framework flexibility is found to play a crucial role in determining the order of spatial arrangement and local structure, self-diffusion coefficient and reorientational dynamics of confined water. Specifically, the DREIDING force field gives rise to an unrealistic stiff framework, enhancing the order of spatial arrangement and diminishing the local ordered structure of confined water. Meanwhile, it results in much slower translational and reorientational dynamics. Hence, the general DREIDING force field cannot be considered for providing a quantitative description of the water structure and dynamics.
Collapse
Affiliation(s)
- Jing Wang
- Center for Membrane Separation and Water Science & Technology, Zhejiang University of Technology, Hangzhou 310014, P. R. China.
| | - Shi-Jie Xie
- Center for Membrane Separation and Water Science & Technology, Zhejiang University of Technology, Hangzhou 310014, P. R. China.
| |
Collapse
|
3
|
Kurapothula PJ, Shepherd S, Wilkins DM. Competing Nuclear Quantum Effects and Hydrogen-Bond Jumps in Hydrated Kaolinite. J Phys Chem Lett 2023; 14:1542-1547. [PMID: 36745462 PMCID: PMC9940297 DOI: 10.1021/acs.jpclett.2c03896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 02/01/2023] [Indexed: 06/18/2023]
Abstract
Recent work has shown that the dynamics of hydrogen bonds in pure clays are affected by nuclear quantum fluctuations, with different effects for the hydrogen bonds holding different layers of the clay together and for those within the same layer. At the clay-water interface there is an even wider range of types of hydrogen bond, suggesting that the quantum effects may be yet more varied. We apply classical and thermostated ring polymer molecular dynamics simulations to show that nuclear quantum effects accelerate hydrogen-bond dynamics to varying degrees. By interpreting the results in terms of the extended jump model of hydrogen-bond switching, we can understand the origins of these effects in terms of changes in the quantum kinetic energy of hydrogen atoms during an exchange. We also show that the extended jump mechanism is applicable not only to the hydrogen bonds involving water, but also those internal to the clay.
Collapse
|
4
|
Amaro-Estrada JI, Wang Y, Torres-Verdín C. Quantifying the Effect of Spatial Confinement on the Diffusion and Nuclear Magnetic Resonance Relaxation of Water/Hydrocarbon Mixtures: A Molecular Dynamics Simulation Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:14540-14549. [PMID: 36399119 DOI: 10.1021/acs.langmuir.2c01357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
We implement molecular dynamics (MD) simulations to explore the relaxation mechanisms involved in the description of translational diffusion and rotational dynamics in water/hydrocarbon interfaces. The analysis of density profiles, self-diffusion coefficients, and nuclear magnetic resonance (NMR) relaxation properties as a function of the confinement layer width and type of hydrocarbons improves the understanding of confined water properties at water/oil interfaces. Density profile fluctuations reveal the presence of water-oil interactions close to the interface. MD results show that self-diffusion coefficients and NMR relaxation times of planar and cylindrical water/oil interfaces are strongly influenced by layer thickness and geometry. Shorter (between 20 and 60%) self-diffusion coefficients and 1H NMR relaxation times were obtained for water/n-pentane, water/n-decane, and water/n-hexadecane systems than bulk diffusion coefficients. An increase in Larmor frequency from 2.3 MHz to 400 MHz shows that longitudinal relaxation time (T1) of confined oil has slightly larger differences at higher frequencies than the transverse relaxation time (T2). At 400 MHz, n-alkanes (n-pentane, n-decane, and n-hexadecane) exhibit longer relaxation times than at smaller frequency values (2.3 and 22 MHz). Analysis of spin-spin and spin-lattice times provides relevant information about inter- and intramolecular relaxation mechanisms of water and oil as a function of geometry and width of the interface layer. These MD results suggest that the strength of confinement and geometry play a vital role in the diffusion and NMR relaxation properties of water/oil interfaces.
Collapse
Affiliation(s)
- Jorge Ivan Amaro-Estrada
- Hildebrand Department of Petroleum and Geosystems Engineering, The University of Texas at Austin, Austin, Texas78712, United States
| | - You Wang
- Hildebrand Department of Petroleum and Geosystems Engineering, The University of Texas at Austin, Austin, Texas78712, United States
| | - Carlos Torres-Verdín
- Hildebrand Department of Petroleum and Geosystems Engineering, The University of Texas at Austin, Austin, Texas78712, United States
| |
Collapse
|
5
|
Tang YB, Xie SJ. Structure and dynamics of a water/methanol mixture confined in zeolitic imidazolate framework ZIF-8 from atomistic simulations. Phys Chem Chem Phys 2022; 24:5220-5232. [PMID: 35167632 DOI: 10.1039/d1cp05571b] [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 classical atomistic simulation study is reported for the microscopic structure and dynamics of a water/methanol mixture confined in flexible nanoporous zeolitic imidazolate framework ZIF-8. Both the radial density distribution and vivid two-dimensional density profile demonstrate that methanol molecules can roughly be viewed as "embedded" between two layers of water molecules to form a "sandwich" structure. The reason for the formation of such a specific structure is explained based on the hydrogen-bonding state and the strength of various hydrogen bonds. The investigation of guest molecular diffusion shows that the self-diffusion coefficient of confined water is generally one to two orders of magnitude smaller than that of bulk water. In addition, the dependence of the self-diffusion coefficient on loading is non-monotonic: the self-diffusion coefficient firstly shows a significant increase and then decreases at higher loading. Moreover, both the structure and dynamics of the hydrogen bond (HB) network of confined water molecules are investigated in a spatially resolved manner. The results indicate that both the HB structure and dynamics of water molecules near the ZIF-8 surface deviate significantly from those of bulk water. However, while water molecules located at the pore center are relatively similar to bulk water molecules with respect to the HB structure, they exhibit strong slowdown in HB dynamics when compared with bulk water. This simulation study elucidates in detail the structural and dynamical properties of a water/methanol mixture in nanoscopic ZIF-8 confinement, which is expected to provide a deep insight into the role of porous fillers, such as ZIF-8, in improving the performance of the dehydration of alcohols via pervaporation and other related processes.
Collapse
Affiliation(s)
- Yu-Bo Tang
- Center for Membrane Separation and Water Science & Technology, Zhejiang University of Technology, Hangzhou 310014, P. R. China.
| | - Shi-Jie Xie
- Center for Membrane Separation and Water Science & Technology, Zhejiang University of Technology, Hangzhou 310014, P. R. China.
| |
Collapse
|
6
|
Randrianandraina J, Badawi M, Cardey B, Grivet M, Groetz JE, Ramseyer C, Anzola FT, Chambelland C, Ducret D. Adsorption of water in Na-LTA zeolites: an ab initio molecular dynamics investigation. Phys Chem Chem Phys 2021; 23:19032-19042. [PMID: 34612441 DOI: 10.1039/d1cp02624k] [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 very wide range of applications of LTA zeolites, including the storage of tritiated water, implies that a detailed and accurate atomic-scale description of the adsorption processes taking place in their structure is crucial. To unravel with an unprecedented accuracy the mechanisms behind the water filling in NaA, we have conducted a systematic ab initio molecular dynamics investigation. Two LTA structural models, the conventional Z4A and the reduced one ZK4, have been used for static and dynamic ab initio calculations, respectively. After assessing this reduced model with comparative static DFT calculations, we start the filling of the α and β cages by water, molecule by molecule. This allowed us to thoroughly study the interaction of water molecules with the zeolite structure and between water molecules, progressively forming H-bond chains and ring patterns as the cage is being filled. The adsorption energies could then be calculated with an unprecedented accuracy, which showed that the interaction of the molecules with the zeolite weakens as their number increases. By these methods, we have been able to highlight the primary role of Na+ cations in the interaction of water with zeolite, and inversely, the role of water in the displacement of cations when it is sufficiently solvated, allowing the passage between the α and β cages. This phenomenon is possible thanks to the inhomogeneous distribution of water molecules on the cationic sites, as shown by our AIMD simulations, which allows the formation of water clusters. These results are important because they help in understanding how the coverage of cationic sites by water will affect the adsorption of other molecules inside the Na-LTA zeolite.
Collapse
Affiliation(s)
- Joharimanitra Randrianandraina
- Laboratoire Chrono-Environnement UMR 6249, Université de Bourgogne Franche-Comté, 16 route de Gray, F-25030 Besançon Cedex, France.
| | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Mitra S, Sharma VK, Mukhopadhyay R. Diffusion of confined fluids in microporous zeolites and clay materials. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2021; 84:066501. [PMID: 33740783 DOI: 10.1088/1361-6633/abf085] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 03/19/2021] [Indexed: 06/12/2023]
Abstract
Fluids exhibit remarkable variation in their structural and dynamic properties when they are confined at the nanoscopic scale. Various factors, including geometric restriction, the size and shape of the guest molecules, the topology of the host, and guest-host interactions, are responsible for the alterations in these properties. Due to their porous structures, aluminosilicates provide a suitable host system for studying the diffusion of sorbates in confinement. Zeolites and clays are two classes of the aluminosilicate family, comprising very ordered porous or layered structures. Zeolitic materials are important due to their high catalytic activity and molecular sieving properties. Guest molecules adsorbed by zeolites display many interesting features including unidimensional diffusion, non-isotropic rotation, preferred orientation and levitation effects, depending on the guest and host characteristics. These are useful for the separation of hydrocarbons which commonly exist as mixtures in nature. Similarly, clay materials have found application in catalysis, desalination, enhanced oil recovery, and isolation barriers used in radioactive waste disposal. It has been shown that the bonding interactions, level of hydration, interlayer spacing, and number of charge-balancing cations are the important factors that determine the nature of diffusion of water molecules in clays. Here, we present a review of the current status of the diffusion mechanisms of various adsorbed species in different microporous zeolites and clays, as investigated using quasielastic neutron scattering and classical molecular dynamics simulation techniques. It is impossible to write an exhaustive review of the subject matter, as it has been explored over several decades and involves many research topics. However, an effort is made to cover the relevant issues specific to the dynamics of different molecules in microporous zeolites and clay materials and to highlight a variety of interesting features that are important for both practical applications and fundamental aspects.
Collapse
Affiliation(s)
- S Mitra
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - V K Sharma
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - R Mukhopadhyay
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| |
Collapse
|
8
|
Baryiames CP, Ma E, Baiz CR. Ions Slow Water Dynamics at Nonionic Surfactant Interfaces. J Phys Chem B 2020; 124:11895-11900. [DOI: 10.1021/acs.jpcb.0c09086] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Christopher P. Baryiames
- Department of Chemistry, University of Texas at Austin, 105 East 24th Street, Stop A5300, Austin, Texas 78712-1224, United States
| | - Emily Ma
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Carlos R. Baiz
- Department of Chemistry, University of Texas at Austin, 105 East 24th Street, Stop A5300, Austin, Texas 78712-1224, United States
| |
Collapse
|
9
|
Piskulich ZA, Laage D, Thompson WH. Activation energies and the extended jump model: How temperature affects reorientation and hydrogen-bond exchange dynamics in water. J Chem Phys 2020; 153:074110. [DOI: 10.1063/5.0020015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Zeke A. Piskulich
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, USA
| | - Damien Laage
- PASTEUR, Départment de Chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS, Paris 75005, France
| | - Ward H. Thompson
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, USA
| |
Collapse
|
10
|
Mouhat F, Coudert FX, Bocquet ML. Structure and chemistry of graphene oxide in liquid water from first principles. Nat Commun 2020; 11:1566. [PMID: 32218448 PMCID: PMC7099009 DOI: 10.1038/s41467-020-15381-y] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 03/04/2020] [Indexed: 12/03/2022] Open
Abstract
Graphene oxide is a rising star among 2D materials, yet its interaction with liquid water remains a fundamentally open question: experimental characterization at the atomic scale is difficult, and modeling by classical approaches cannot properly describe chemical reactivity. Here, we bridge the gap between simple computational models and complex experimental systems, by realistic first-principles molecular simulations of graphene oxide (GO) in liquid water. We construct chemically accurate GO models and study their behavior in water, showing that oxygen-bearing functional groups (hydroxyl and epoxides) are preferentially clustered on the graphene oxide layer. We demonstrated the specific properties of GO in water, an unusual combination of both hydrophilicity and fast water dynamics. Finally, we evidence that GO is chemically active in water, acquiring an average negative charge of the order of 10 mC m-2. The ab initio modeling highlights the uniqueness of GO structures for applications as innovative membranes for desalination and water purification.
Collapse
Affiliation(s)
- Félix Mouhat
- PASTEUR, Département de Chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS, 24 Rue Lhomond 75005, Paris, France
| | - François-Xavier Coudert
- Chimie ParisTech, PSL University, CNRS, Institut de Recherche de Chimie Paris, 75005, Paris, France
| | - Marie-Laure Bocquet
- PASTEUR, Département de Chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS, 24 Rue Lhomond 75005, Paris, France.
| |
Collapse
|
11
|
Ahsan SAMS, Durani S, Reddy G, Subramanian Y. Shared hydrogen bonds: water in aluminated faujasite. Phys Chem Chem Phys 2020; 22:1632-1639. [PMID: 31894781 DOI: 10.1039/c9cp04972j] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Water confined in faujasite, a zeolite, with aluminium content, exhibits properties different from those of bulk water as well as water confined in siliceous faujasite. The RDF between oxygen of water (OW) and oxygen of aluminium (OAl) shows a prominent first peak near to 2.9 Å similar to any oxygen-oxygen RDF seen in bulk water and unlike water confined in siliceous faujasite. Further, HW-OAl shows a peak near 1.9 Å suggesting hydrogen bonding between hydrogen of water and OAl. The water satisfies the hydrogen bond criteria with both O1Al and O2Al indicating that it is participating in a shared hydrogen bond. The hydrogen bond exchange between such a water forming a shared hydrogen bond to OAl and another water molecule H2Ob is investigated through the changes in the distances and appropriate angles. The O-Al-O angle of the zeolite increases by about 7 degrees on the formation of the shared hydrogen bond. The jump dynamics of the shared hydrogen bond when the two bonds break simultaneously has been obtained and this is reported. This jump reorientation dynamics is different compared to normal hydrogen bonding reported by Laage and Hynes: it has a short lifetime, around 50-100 fs computed from SHB(t). The intermittent and continuous hydrogen bond correlation functions are also reported.
Collapse
Affiliation(s)
- S A M Shamimul Ahsan
- Atomic Mineral Directorate For Exploration & Research, Nagarbhavi, Bangalore-560072, India
| | - Smeer Durani
- Atomic Mineral Directorate For Exploration & Research, R. K. Puram, New Delhi-110066, India
| | - Govardhan Reddy
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore-560012, India.
| | - Yashonath Subramanian
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore-560012, India.
| |
Collapse
|
12
|
Caratelli C, Hajek J, Meijer EJ, Waroquier M, Van Speybroeck V. Dynamic Interplay between Defective UiO-66 and Protic Solvents in Activated Processes. Chemistry 2019; 25:15315-15325. [PMID: 31461187 PMCID: PMC6916623 DOI: 10.1002/chem.201903178] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Indexed: 01/24/2023]
Abstract
UiO‐66, composed by Zr‐oxide inorganic bricks [Zr6(μ3‐O)4(μ3‐OH)4] and organic terephthalate linkers, is one of the most studied metal–organic frameworks (MOFs) due to its exceptional thermal, chemical, and mechanical stability. Thanks to its high connectivity, the material can withstand structural deformations during activation processes such as linker exchange, dehydration, and defect formation. These processes do alter the zirconium coordination number in a dynamic way, creating open metal sites for catalysis and thus are able to tune the catalytic properties. In this work, it is shown, by means of first‐principle molecular‐dynamics simulations at operating conditions, how protic solvents may facilitate such changes in the metal coordination. Solvent can induce structural rearrangements in the material that can lead to undercoordinated but also overcoordinated metal sites. This is demonstrated by simulating activation processes along well‐chosen collective variables. Such enhanced MD simulations are able to track the intrinsic dynamics of the framework at realistic conditions.
Collapse
Affiliation(s)
- Chiara Caratelli
- Center for Molecular Modeling, Ghent University, Technologiepark 46, 9052, Zwijnaarde, Belgium
| | - Julianna Hajek
- Center for Molecular Modeling, Ghent University, Technologiepark 46, 9052, Zwijnaarde, Belgium
| | - Evert Jan Meijer
- Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098, XH, Amsterdam, The Netherlands
| | - Michel Waroquier
- Center for Molecular Modeling, Ghent University, Technologiepark 46, 9052, Zwijnaarde, Belgium
| | | |
Collapse
|
13
|
Lépori CMO, Correa NM, Silber JJ, Vaca Chávez F, Falcone RD. Interfacial properties modulated by the water confinement in reverse micelles created by the ionic liquid-like surfactant bmim-AOT. SOFT MATTER 2019; 15:947-955. [PMID: 30644504 DOI: 10.1039/c8sm02217h] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The behavior of the interfacial water entrapped in reverse micelles (RMs) that were formed by the ionic liquid-like surfactant 1-butyl-3-methylimidazolium 1,4-bis-2-ethylhexylsulfosuccinate (bmim-AOT) was investigated with the use of UV-Vis absorption spectroscopy and nuclear magnetic resonance (NMR) relaxometry. The solvatochromism of two molecular probes, namely, 1-methyl-8-oxyquinolinium betaine (QB) and N,N,N',N'-tetramethylethylenediamine copper(ii)acetylacetonate tetraphenylborate ([Cu(acac)(tmen)][B(C6H5)4]), was investigated. As a comparison, the analog RMs formed by sodium 1,4-bis-2-ethylhexylsulfosuccinate (Na-AOT) were also explored. By varying the water content inside the RMs and consequently the different magnitude of the water-surfactant interactions at the interface, interesting properties were observed by comparing bmim-AOT and Na-AOT RMs. From the solvatochromic behavior of ([Cu(acac)(tmen)][B(C6H5)4]), we found that the interface in bmim-AOT RMs shows a smaller electron donating capacity than that in Na-AOT RMs. QB revealed that the interfacial region is a weaker hydrogen bond donor and less polar than the corresponding Na-AOT RMs. NMR experiments showed that the molecular motion of water in bmim-AOT RMs is less restricted than that of the water molecules confined in Na-AOT RMs. In summary, the results show how the nature of the bmim+ cation affects the interaction between the entrapped water and the RM interface, greatly modifying the interfacial water structure in comparison with the results known for Na-AOT.
Collapse
Affiliation(s)
- Cristian M O Lépori
- Departamento de Química, Universidad Nacional de Río Cuarto, Agencia Postal # 3, C.P. X5804BYA Río Cuarto, Argentina.
| | | | | | | | | |
Collapse
|
14
|
Affiliation(s)
- Ward H. Thompson
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, USA
| |
Collapse
|
15
|
Scalfi L, Fraux G, Boutin A, Coudert FX. Structure and Dynamics of Water Confined in Imogolite Nanotubes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:6748-6756. [PMID: 29782170 DOI: 10.1021/acs.langmuir.8b01115] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We have studied the properties of water adsorbed inside nanotubes of hydrophilic imogolite, an aluminum silicate clay mineral, by means of molecular simulations. We used a classical force field to describe the water and the flexible imogolite nanotube and validated it against the data obtained from first-principles molecular dynamics. With it, we observe a strong structuration of the water confined in the nanotube, with specific adsorption sites and a distribution of hydrogen bond patterns. The combination of number of adsorption sites, their geometry, and the preferential tetrahedral hydrogen bonding pattern of water leads to frustration and disorder. We further characterize the dynamics of the water, as well as the hydrogen bonds formed between water molecules and the nanotube, which is found to be more than 1 order of magnitude longer than water-water hydrogen bonds.
Collapse
Affiliation(s)
- Laura Scalfi
- PASTEUR, Département de Chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS , 75005 Paris , France
| | - Guillaume Fraux
- Chimie ParisTech, PSL University, CNRS, Institut de Recherche de Chimie Paris , 75005 Paris , France
| | - Anne Boutin
- PASTEUR, Département de Chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS , 75005 Paris , France
| | - François-Xavier Coudert
- Chimie ParisTech, PSL University, CNRS, Institut de Recherche de Chimie Paris , 75005 Paris , France
| |
Collapse
|
16
|
Stirnemann G, Duboué-Dijon E, Laage D. Ab Initio Simulations of Water Dynamics in Aqueous TMAO Solutions: Temperature and Concentration Effects. J Phys Chem B 2017; 121:11189-11197. [PMID: 29200289 DOI: 10.1021/acs.jpcb.7b09989] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We use ab initio molecular dynamics simulation to study the effect of hydrophobic groups on the dynamics of water molecules in aqueous solutions of trimethylamine N-oxide (TMAO). We show that hydrophobic groups induce a moderate (<2-fold) slowdown of water reorientation and hydrogen-bond dynamics in dilute solutions, but that this slowdown rapidly increases with solute concentration. In addition, the slowdown factor is found to vary very little with temperature, thus suggesting an entropic origin. All of these results are in quantitative agreement with prior classical molecular dynamics simulations and with the previously suggested excluded-volume model. The hydrophilic TMAO headgroup is found to affect water dynamics more strongly than the hydrophobic moiety, and the magnitude of this slowdown is very sensitive to the strength of the water-solute hydrogen-bond.
Collapse
Affiliation(s)
- Guillaume Stirnemann
- CNRS Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique, Univ. Paris Diderot, Sorbonne Paris Cité, PSL Research University , 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Elise Duboué-Dijon
- PASTEUR, Département de Chimie, École Normale Supérieure, PSL Research University, Sorbonne Universités, UPMC Univ. Paris 06, CNRS , 75005 Paris, France
| | - Damien Laage
- PASTEUR, Département de Chimie, École Normale Supérieure, PSL Research University, Sorbonne Universités, UPMC Univ. Paris 06, CNRS , 75005 Paris, France
| |
Collapse
|
17
|
Alarcos N, Cohen B, Ziółek M, Douhal A. Photochemistry and Photophysics in Silica-Based Materials: Ultrafast and Single Molecule Spectroscopy Observation. Chem Rev 2017; 117:13639-13720. [PMID: 29068670 DOI: 10.1021/acs.chemrev.7b00422] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Silica-based materials (SBMs) are widely used in catalysis, photonics, and drug delivery. Their pores and cavities act as hosts of diverse guests ranging from classical dyes to drugs and quantum dots, allowing changes in the photochemical behavior of the confined guests. The heterogeneity of the guest populations as well as the confinement provided by these hosts affect the behavior of the formed hybrid materials. As a consequence, the observed reaction dynamics becomes significantly different and complex. Studying their photobehavior requires advanced laser-based spectroscopy and microscopy techniques as well as computational methods. Thanks to the development of ultrafast (spectroscopy and imaging) tools, we are witnessing an increasing interest of the scientific community to explore the intimate photobehavior of these composites. Here, we review the recent theoretical and ultrafast experimental studies of their photodynamics and discuss the results in comparison to those in homogeneous media. The discussion of the confined dynamics includes solvation and intra- and intermolecular proton-, electron-, and energy transfer events of the guest within the SBMs. Several examples of applications in photocatalysis, (photo)sensors, photonics, photovoltaics, and drug delivery demonstrate the vast potential of the SBMs in modern science and technology.
Collapse
Affiliation(s)
- Noemí Alarcos
- Departamento de Química Física, Facultad de Ciencias Ambientales y Bioquímica, and INAMOL, Universidad de Castilla-La Mancha , Avenida Carlos III, S.N., 45071 Toledo, Spain
| | - Boiko Cohen
- Departamento de Química Física, Facultad de Ciencias Ambientales y Bioquímica, and INAMOL, Universidad de Castilla-La Mancha , Avenida Carlos III, S.N., 45071 Toledo, Spain
| | - Marcin Ziółek
- Quantum Electronics Laboratory, Faculty of Physics, Adam Mickiewicz University , Umultowska 85, 61-614 Poznań, Poland
| | - Abderrazzak Douhal
- Departamento de Química Física, Facultad de Ciencias Ambientales y Bioquímica, and INAMOL, Universidad de Castilla-La Mancha , Avenida Carlos III, S.N., 45071 Toledo, Spain
| |
Collapse
|
18
|
Fraux G, Coudert FX, Boutin A, Fuchs AH. Forced intrusion of water and aqueous solutions in microporous materials: from fundamental thermodynamics to energy storage devices. Chem Soc Rev 2017; 46:7421-7437. [PMID: 29051934 DOI: 10.1039/c7cs00478h] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We review the high pressure forced intrusion studies of water in hydrophobic microporous materials such as zeolites and MOFs, a field of research that has emerged some 15 years ago and is now very active. Many of these studies are aimed at investigating the possibility of using these systems as energy storage devices. A series of all-silica zeolites (zeosil) frameworks were found suitable for reversible energy storage because of their stability with respect to hydrolysis after several water intrusion-extrusion cycles. Several microporous hydrophobic zeolite imidazolate frameworks (ZIFs) also happen to be quite stable and resistant towards hydrolysis and thus seem very promising for energy storage applications. Replacing pure water by electrolyte aqueous solutions enables to increase the stored energy by a factor close to 3, on account of the high pressure shift of the intrusion transition. In addition to the fact that aqueous solutions and microporous silica materials are environmental friendly, these systems are thus becoming increasingly interesting for the design of new energy storage devices. This review also addresses the theoretical approaches and molecular simulations performed in order to better understand the experimental behavior of nano-confined water. Molecular simulation studies showed that water condensation takes place through a genuine first-order phase transition, provided that the interconnected pores structure is 3-dimensional and sufficiently open. In an extreme confinement situations such as in ferrierite zeosil, condensation seem to take place through a continuous supercritical crossing from a diluted to a dense fluid, on account of the fact that the first-order transition line is shifted to higher pressure, and the confined water critical point is correlatively shifted to lower temperature. These molecular simulation studies suggest that the most important features of the intrusion/extrusion process can be understood in terms of equilibrium thermodynamics considerations.
Collapse
Affiliation(s)
- Guillaume Fraux
- Chimie ParisTech, PSL Research University, CNRS, Institut de Recherche de Chimie, Paris, 75005 Paris, France.
| | - François-Xavier Coudert
- Chimie ParisTech, PSL Research University, CNRS, Institut de Recherche de Chimie, Paris, 75005 Paris, France.
| | - Anne Boutin
- PASTEUR, École normale supérieure, PSL Research University, Sorbonne Universités, UPMC Univ. Paris 06, CNRS, 75005 Paris, France
| | - Alain H Fuchs
- Chimie ParisTech, PSL Research University, CNRS, Institut de Recherche de Chimie, Paris, 75005 Paris, France.
| |
Collapse
|
19
|
Villa CC, Silber JJ, Falcone RD, Correa NM. Subtleties of catanionic surfactant reverse micelle assemblies revealed by a fluorescent molecular probe. Methods Appl Fluoresc 2017; 5:044001. [PMID: 28653961 DOI: 10.1088/2050-6120/aa7b64] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
In this work, the absorption and emission behavior of the cationic hemicyanine trans-4-[4-(dimethylamino)styryl]-N-methylpyridinium iodide (HC) in reverse micelles (RMs) formed by the catanionic surfactants benzyl-n-hexadecyldimethylammonium-1,4-bis-2-ethylhexylsulfosuccinate (AOT-BHD) and cetyltrimethylammonium-1,4-bis-2-ethylhexylsulfosuccinate (AOT-CTA) have been investigated. Our results show that the spectroscopic behavior of HC changes when the dye is dissolved in AOT-BHD or in AOT-CTA RMs. While HC undergoes an intramolecular charge-transfer process upon excitation in AOT-CTA RMs, in AOT-BHD RMs this process is inhibited due to a specific interaction between HC and the polar head group of the BHD+ cation. This implies that the chemical structure of CTA+ and BHD+ cations has a large impact on the excited stated from which HC emission occurs. Additionally, the structural difference between the two cations impacts on the water-RM interface interaction, which provides a way of controlling the solvation process in these RMs. Furthermore, differences in the interfacial fluidity between the two catanionic RMs is observed, a result that is particularly interesting with regard to these systems being used as nanoreactors.
Collapse
|
20
|
Abstract
The structure and function of biomolecules are strongly influenced by their hydration shells. Structural fluctuations and molecular excitations of hydrating water molecules cover a broad range in space and time, from individual water molecules to larger pools and from femtosecond to microsecond time scales. Recent progress in theory and molecular dynamics simulations as well as in ultrafast vibrational spectroscopy has led to new and detailed insight into fluctuations of water structure, elementary water motions, electric fields at hydrated biointerfaces, and processes of vibrational relaxation and energy dissipation. Here, we review recent advances in both theory and experiment, focusing on hydrated DNA, proteins, and phospholipids, and compare dynamics in the hydration shells to bulk water.
Collapse
Affiliation(s)
- Damien Laage
- École
Normale Supérieure, PSL Research University, UPMC Univ Paris
06, CNRS, Département de Chimie,
PASTEUR, 24 rue Lhomond, 75005 Paris, France
- Sorbonne
Universités, UPMC Univ Paris 06, ENS, CNRS, PASTEUR, 75005 Paris, France
| | - Thomas Elsaesser
- Max-Born-Institut
für Nichtlineare Optik und Kurzzeitspektroskopie, D-12489 Berlin, Germany
| | - James T. Hynes
- École
Normale Supérieure, PSL Research University, UPMC Univ Paris
06, CNRS, Département de Chimie,
PASTEUR, 24 rue Lhomond, 75005 Paris, France
- Sorbonne
Universités, UPMC Univ Paris 06, ENS, CNRS, PASTEUR, 75005 Paris, France
- Department
of Chemistry and Biochemistry, University
of Colorado, Boulder, Colorado 80309, United
States
| |
Collapse
|
21
|
Foroutan M, Fatemi SM, Esmaeilian F. A review of the structure and dynamics of nanoconfined water and ionic liquids via molecular dynamics simulation. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2017; 40:19. [PMID: 28229319 DOI: 10.1140/epje/i2017-11507-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 01/30/2017] [Indexed: 05/04/2023]
Abstract
During the past decade, the research on fluids in nanoconfined geometries has received considerable attention as a consequence of their wide applications in different fields. Several nanoconfined systems such as water and ionic liquids, together with an equally impressive array of nanoconfining media such as carbon nanotube, graphene and graphene oxide have received increasingly growing interest in the past years. Water is the first system that has been reviewed in this article, due to its important role in transport phenomena in environmental sciences. Water is often considered as a highly nanoconfined system, due to its reduction to a few layers of water molecules between the extended surface of large macromolecules. The second system discussed here is ionic liquids, which have been widely studied in the modern green chemistry movement. Considering the great importance of ionic liquids in industry, and also their oil/water counterpart, nanoconfined ionic liquid system has become an important area of research with many fascinating applications. Furthermore, the method of molecular dynamics simulation is one of the major tools in the theoretical study of water and ionic liquids in nanoconfinement, which increasingly has been joined with experimental procedures. In this way, the choice of water and ionic liquids in nanoconfinement is justified by applying molecular dynamics simulation approaches in this review article.
Collapse
Affiliation(s)
- Masumeh Foroutan
- Department of Physical Chemistry, School of Chemistry, College of Science, University of Tehran, Tehran, Iran.
| | - S Mahmood Fatemi
- Department of Physical Chemistry, School of Chemistry, College of Science, University of Tehran, Tehran, Iran
| | - Farshad Esmaeilian
- Department of Physical Chemistry, School of Chemistry, College of Science, University of Tehran, Tehran, Iran
| |
Collapse
|
22
|
Duboué-Dijon E, Fogarty AC, Hynes JT, Laage D. Dynamical Disorder in the DNA Hydration Shell. J Am Chem Soc 2016; 138:7610-20. [DOI: 10.1021/jacs.6b02715] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Elise Duboué-Dijon
- École Normale
Supérieure, PSL Research University, UPMC Univ Paris 06, CNRS,
Département de Chimie, PASTEUR, 24 rue Lhomond, 75005 Paris, France
- Sorbonne Universités,
UPMC Univ Paris 06, ENS, CNRS, PASTEUR, 75005 Paris, France
| | - Aoife C. Fogarty
- École Normale
Supérieure, PSL Research University, UPMC Univ Paris 06, CNRS,
Département de Chimie, PASTEUR, 24 rue Lhomond, 75005 Paris, France
- Sorbonne Universités,
UPMC Univ Paris 06, ENS, CNRS, PASTEUR, 75005 Paris, France
| | - James T. Hynes
- École Normale
Supérieure, PSL Research University, UPMC Univ Paris 06, CNRS,
Département de Chimie, PASTEUR, 24 rue Lhomond, 75005 Paris, France
- Sorbonne Universités,
UPMC Univ Paris 06, ENS, CNRS, PASTEUR, 75005 Paris, France
- Department
of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - Damien Laage
- École Normale
Supérieure, PSL Research University, UPMC Univ Paris 06, CNRS,
Département de Chimie, PASTEUR, 24 rue Lhomond, 75005 Paris, France
- Sorbonne Universités,
UPMC Univ Paris 06, ENS, CNRS, PASTEUR, 75005 Paris, France
| |
Collapse
|
23
|
Lépori CMO, Correa NM, Silber JJ, Falcone RD. How the cation 1-butyl-3-methylimidazolium impacts the interaction between the entrapped water and the reverse micelle interface created with an ionic liquid-like surfactant. SOFT MATTER 2016; 12:830-844. [PMID: 26542472 DOI: 10.1039/c5sm02421h] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The behavior of the interfacial water entrapped in reverse micelles (RMs) formed by the ionic liquid-like surfactant 1-butyl-3-methylimidazolium 1,4-bis-2-ethylhexylsulfosuccinate (bmim-AOT) dissolved in benzene (or chlorobenzene) was investigated using noninvasive techniques such as dynamic light scattering (DLS), static light scattering (SLS), FT-IR and (1)H NMR. The DLS and SLS results reveal the formation of discrete spherical and non-interacting water droplets stabilized by the bmim-AOT surfactant. Moreover, since the droplet size increases as the W0 (W0 = [water]/[surfactant]) value increases, water interacts with the RM interface. From FT-IR and (1)H NMR data, a weaker water-surfactant interaction in bmim-AOT RMs in comparison with the RMs created by sodium 1,4-bis-2-ethylhexylsulfosuccinate (Na-AOT) is detected. Consequently, there are less water molecules interacting with the interface in bmim-AOT RMs, and their hydrogen bond network is not completely disrupted as they are in Na-AOT RMs. The results show how the nature of the new cation impacts the interaction between the entrapped water and the RM interface, modifying the interfacial water structure in comparison with the results known for Na-AOT.
Collapse
Affiliation(s)
- Cristian M O Lépori
- Departamento de Química, Universidad Nacional de Río Cuarto, Agencia Postal # 3, C.P. X5804BYA Río Cuarto, Argentina.
| | | | | | | |
Collapse
|
24
|
Mesele OO, Vartia AA, Laage D, Thompson WH. Reorientation of Isomeric Butanols: The Multiple Effects of Steric Bulk Arrangement on Hydrogen-Bond Dynamics. J Phys Chem B 2015; 120:1546-59. [DOI: 10.1021/acs.jpcb.5b07692] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Oluwaseun O. Mesele
- Department
of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Anthony A. Vartia
- Department
of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Damien Laage
- Department
of Chemistry, Ecole Normale Supérieure, UMR ENS-CNRS-UPMC 8640, 24 rue Lhmond, 75005 Paris, France
| | - Ward H. Thompson
- Department
of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| |
Collapse
|
25
|
Usui K, Hunger J, Sulpizi M, Ohto T, Bonn M, Nagata Y. Ab Initio Liquid Water Dynamics in Aqueous TMAO Solution. J Phys Chem B 2015; 119:10597-606. [DOI: 10.1021/acs.jpcb.5b02579] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kota Usui
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany
| | - Johannes Hunger
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany
| | - Marialore Sulpizi
- Johannes Gutenberg University Mainz, Staudingerweg 7, 55099 Mainz, Germany
| | - Tatsuhiko Ohto
- Graduate
School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
| | - Mischa Bonn
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany
| | - Yuki Nagata
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany
| |
Collapse
|
26
|
Fogarty AC, Duboué-Dijon E, Laage D, Thompson WH. Origins of the non-exponential reorientation dynamics of nanoconfined water. J Chem Phys 2014; 141:18C523. [DOI: 10.1063/1.4896983] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Aoife C. Fogarty
- Ecole Normale Supérieure - PSL Research University, Département de Chimie, Sorbonne Universités - UPMC Univ Paris 06, CNRS UMR 8640 PASTEUR, 24 rue Lhomond, 75005 Paris, France
| | - Elise Duboué-Dijon
- Ecole Normale Supérieure - PSL Research University, Département de Chimie, Sorbonne Universités - UPMC Univ Paris 06, CNRS UMR 8640 PASTEUR, 24 rue Lhomond, 75005 Paris, France
| | - Damien Laage
- Ecole Normale Supérieure - PSL Research University, Département de Chimie, Sorbonne Universités - UPMC Univ Paris 06, CNRS UMR 8640 PASTEUR, 24 rue Lhomond, 75005 Paris, France
| | - Ward H. Thompson
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, USA
| |
Collapse
|
27
|
Medders GR, Paesani F. Water Dynamics in Metal-Organic Frameworks: Effects of Heterogeneous Confinement Predicted by Computational Spectroscopy. J Phys Chem Lett 2014; 5:2897-902. [PMID: 26278096 DOI: 10.1021/jz5013998] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The behavior of water confined in MIL-53(Cr), a flexible metal-organic framework (MOF), is investigated through computational infrared spectroscopy. As the number of molecules adsorbed inside of the pores increases, the water OH stretch band of the linear infrared spectrum grows in intensity and approaches that of bulk water. To assess whether the water confined in MIL-53(Cr) becomes liquid-like, two-dimensional infrared spectra (2DIR) are also calculated. Confinement effects result in distinct chemical environments that appear as specific features in the 2DIR spectra. The evolution of the 2DIR line shape as a function of waiting time is well described in terms of the orientational dynamics of the water molecules, with chemical exchange cross peaks appearing at a time scale similar to the hydrogen bond rearrangement lifetime. The confining environment considerably slows the hydrogen bond dynamics relative to bulk as a result of the competition between water-framework and water-water interactions.
Collapse
Affiliation(s)
- Gregory R Medders
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Francesco Paesani
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
| |
Collapse
|
28
|
Villa CC, Silber JJ, Correa NM, Falcone RD. Effect of the cationic surfactant moiety on the structure of water entrapped in two catanionic reverse micelles created from ionic liquid-like surfactants. Chemphyschem 2014; 15:3097-109. [PMID: 25044685 DOI: 10.1002/cphc.201402307] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Indexed: 11/08/2022]
Abstract
The behavior of water entrapped in reverse micelles (RMs) formed by two catanionic ionic liquid-like surfactants, benzyl-n-hexadecyldimethylammonium 1,4-bis-2-ethylhexylsulfosuccinate (AOT-BHD) and cetyltrimethylammonium 1,4-bis-2-ethylhexylsulfosuccinate (AOT-CTA), was investigated by using dynamic (DLS) and static (SLS) light scattering, FTIR, and (1)H NMR spectroscopy techniques. To the best of our knowledge, this is the first report in which AOT-CTA has been used to create RMs and encapsulate water. DLS and SLS results revealed the formation of RMs in benzene and the interaction of water with the RM interface. From FTIR and (1)H NMR spectroscopy data, a difference in the magnitude of the water-catanionic surfactant interaction at the interface is observed. For the AOT-BHD RMs, a strong water-surfactant interaction can be invoked whereas for AOT-CTA this interaction seems to be weaker. Consequently, more water molecules interact with the interface in AOT-BHD RMs with a completely disrupted hydrogen-bond network, than in AOT-CTA RMs in which the water structure is partially preserved. We suggest that the benzyl group present in the BHD(+) moiety in AOT-BHD is responsible for the behavior of the catanionic interface in comparison with the interface created in AOT-CTA. These results show that a simple change in the cationic component in the catanionic surfactant promotes remarkable changes in the RMs interface with interesting consequences, in particular when using the systems as nanoreactors.
Collapse
Affiliation(s)
- Cristian C Villa
- Departamento de Química, Universidad Nacional de Río Cuarto, Agencia Postal # 3. C.P. X5804BYA Río Cuarto (Argentina)
| | | | | | | |
Collapse
|
29
|
Duboué-Dijon E, Fogarty AC, Laage D. Temperature dependence of hydrophobic hydration dynamics: from retardation to acceleration. J Phys Chem B 2014; 118:1574-83. [PMID: 24460522 DOI: 10.1021/jp408603n] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The perturbation induced by a hydrophobic solute on water dynamics is essential in many biochemical processes, but its mechanism and magnitude are still debated. A stringent test of the different proposed pictures is provided by recent NMR measurements by Qvist and Halle (J. Am. Chem. Soc. 2008, 130, 10345-10353) which showed that, unexpectedly, the perturbation changes in a non-monotonic fashion when the solution is cooled below room temperature. Here we perform and analyze molecular dynamics simulations of a small paradigm amphiphilic solute, trimethylamine N-oxide (TMAO), in dilute aqueous solutions over the 218-350 K temperature range. We first show that our simulations properly reproduce the non-monotonic temperature dependence. We then develop a model which combines our previously suggested entropic excluded-volume effect with a perturbation factor arising from the difference between local structural fluctuations in the shell and the bulk. Our model provides a detailed molecular understanding of the hydrophobic perturbation over the full temperature range investigated. It shows that the excluded-volume factor brings a dominant temperature-independent contribution to the perturbation at all temperatures, and provides a very good approximation at room temperature. The non-monotonic temperature dependence of the perturbation is shown to arise from the structural factor and mostly from relative shifts between the shell and bulk distributions of local structures, whose amplitude remains very small compared to the widths of those distributions.
Collapse
Affiliation(s)
- Elise Duboué-Dijon
- Department of Chemistry, École Normale Supérieure , UMR ENS-CNRS-UPMC 8640, 24 rue Lhomond, 75005 Paris, France
| | | | | |
Collapse
|
30
|
Ortiz AU, Freitas AP, Boutin A, Fuchs AH, Coudert FX. What makes zeolitic imidazolate frameworks hydrophobic or hydrophilic? The impact of geometry and functionalization on water adsorption. Phys Chem Chem Phys 2014; 16:9940-9. [DOI: 10.1039/c3cp54292k] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|