1
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Garrett P, Baiz CR. Hidden Beneath the Layers: Extending the Core/Shell Model of Reverse Micelles. J Phys Chem B 2023; 127:9399-9404. [PMID: 37870992 DOI: 10.1021/acs.jpcb.3c04978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Reverse micelles (RMs) provide a unique and highly tunable model system to study water in confined environments. The complex properties of water within RMs arise from the disruption of extended hydrogen bond (H-bond) networks that mediate local and long-range dynamics in bulk aqueous systems. Modulating the water pool size influences its H-bond dynamics, with smaller RMs increasingly restricting the H-bond network rearrangements leading to slower dynamics; however, within small confined systems, the dynamics of the surfactants also influence the water dynamics. Using ultrafast two-dimensional infrared spectroscopy, we investigate the effects of RM size on the surfactant headgroup rotamer populations and picosecond interfacial H-bond dynamics of aerosol-OT surfactants. We find that the increased water penetration accelerates H-bond dynamics, with larger RMs showing faster dynamics. These results imply that the changes in the RM structure alter the physical structure of the RM interface and thus alter the solvation dynamics. The findings in this study can be used for developing models for structure-specific solvation dynamics that account for the surfactant packing and hydration at the interface.
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Affiliation(s)
- Paul Garrett
- Department of Chemistry, the University of Texas at Austin, Austin, Texas 78712, United States
| | - Carlos R Baiz
- Department of Chemistry, the University of Texas at Austin, Austin, Texas 78712, United States
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2
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Crowder M, Tahiry F, Lizarraga I, Rodriguez S, Peña N, Sharma AK. Computatiaonal Analysis of Water Dynamics in AOT Reverse Micelles. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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3
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van Dam EP, Gouzy R, Pelan E, Velikov KP, Bakker HJ. Water reorientation dynamics in colloidal water-oil emulsions. Phys Chem Chem Phys 2021; 23:27024-27030. [PMID: 34846395 DOI: 10.1039/d1cp03182a] [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
We study the molecular-scale properties of colloidal water-oil emulsions consisting of 120-290 nm oil droplets embedded in water. This type of emulsion can be prepared with low concentrations of surfactants and is usually kinetically stable. Even though colloidal water-oil emulsions are used ubiquitously, their molecular properties are still poorly understood. Here we study the orientational dynamics of water molecules in these emulsions using polarization resolved pump-probe infrared spectroscopy, for varying surfactant concentrations, droplet sizes, and temperatures. We find that the majority of the water molecules reorients with the same time constant as in bulk water, while a small fraction of the water molecules reorients on a much longer time scale. These slowly reorienting water molecules are interacting with the surface of the oil droplets. The fraction of slowly orienting water molecules is proportional to the oil volume fraction, and shows a negligible dependence on the average droplet size. This finding indicates that the total surface area of the oil droplets is quite independent of the average droplet size, which indicates that the larger oil droplets are quite corrugated, showing large protrusions into the water phase.
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Affiliation(s)
| | - Roland Gouzy
- Unilever Innovation Centre Wageningen, Bronland 14, 6708 WH Wageningen, The Netherlands
| | - Eddie Pelan
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Krassimir P Velikov
- Unilever Innovation Centre Wageningen, Bronland 14, 6708 WH Wageningen, The Netherlands.,Van der Waals-Zeeman Institute, Institute of Physics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.,Soft Condensed Matter, Debye Institute for NanoMaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands
| | - Huib J Bakker
- AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands.
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4
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Versatility of Reverse Micelles: From Biomimetic Models to Nano (Bio)Sensor Design. Processes (Basel) 2021. [DOI: 10.3390/pr9020345] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
This paper presents an overview of the principal structural and dynamics characteristics of reverse micelles (RMs) in order to highlight their structural flexibility and versatility, along with the possibility to modulate their parameters in a controlled manner. The multifunctionality in a large range of different scientific fields is exemplified in two distinct directions: a theoretical model for mimicry of the biological microenvironment and practical application in the field of nanotechnology and nano-based sensors. RMs represent a convenient experimental approach that limits the drawbacks of the conventionally biological studies in vitro, while the particular structure confers them the status of simplified mimics of cells by reproducing a complex supramolecular organization in an artificial system. The biological relevance of RMs is discussed in some particular cases referring to confinement and a crowded environment, as well as the molecular dynamics of water and a cell membrane structure. The use of RMs in a range of applications seems to be more promising due to their structural and compositional flexibility, high efficiency, and selectivity. Advances in nanotechnology are based on developing new methods of nanomaterial synthesis and deposition. This review highlights the advantages of using RMs in the synthesis of nanoparticles with specific properties and in nano (bio)sensor design.
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5
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Roy VP, Kubarych KJ. A simple lattice Monte Carlo simulation to model interfacial and crowded water rearrangements. Chem Phys 2020. [DOI: 10.1016/j.chemphys.2019.110653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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6
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Interfacial and Nanoconfinement Effects Decrease the Excited-State Acidity of Polymer-Bound Photoacids. Chem 2019. [DOI: 10.1016/j.chempr.2019.04.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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7
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Wei Q, Zhang M, Zhou D, Li X, Bian H, Fang Y. Ultrafast Hydrogen Bond Exchanging between Water and Anions in Concentrated Ionic Liquid Aqueous Solutions. J Phys Chem B 2019; 123:4766-4775. [PMID: 31082232 DOI: 10.1021/acs.jpcb.9b03504] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The mixtures of 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) ionic liquids (ILs) and water as a function of IL concentrations have been investigated by Fourier transform infrared (FTIR) spectroscopy and ultrafast two-dimensional IR (2D IR) spectroscopy. FTIR spectra of the mixtures resolve two different types of water species, one interacting with the BF4- anions and the other associated with bulklike water molecules. These two water species are in a dynamic equilibrium through forming different hydrogen bonding configurations which are separated by more than 100 cm-1 in the IR spectra. The structural dynamics of the IL mixtures are further revealed by monitoring the vibrational relaxation dynamics of the OD stretching group of interfacial water molecules hydrogen bonded to BF4- anions. With the increase of the IL bulk concentration, vibrational population and rotational dynamics of the interfacial water molecules can be described by a biexponential decay function and are strongly dependent on the IL concentrations. Furthermore, the ultrafast hydrogen bond exchanging between water and BF4- anions in the ILs are also measured using 2D IR spectroscopy. The average hydrogen bond exchanging rate is determined to be 19 ± 4 ps, which is around 3 times slower than that in the NaBF4 electrolyte aqueous solution. The much slower hydrogen bond exchanging rate indicates that the local structure of ILs and water molecules are strongly mediated by the steric effect of the cationic group in the ILs, which is proposed to be responsible for the formation of the heterogeneous structure in the IL mixtures. By using SCN- as the anionic probe, the structural inhomogeneity in the IL solutions can be confirmed from the distinct rotational dynamics of the SCN-, which is segregated from the rotational dynamics of water molecules in the IL mixtures.
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Affiliation(s)
- Qianshun Wei
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering , Shaanxi Normal University , Xi'an 710119 , China
| | - Miaomiao Zhang
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering , Shaanxi Normal University , Xi'an 710119 , China
| | - Dexia Zhou
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering , Shaanxi Normal University , Xi'an 710119 , China
| | - Xiaoqian Li
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering , Shaanxi Normal University , Xi'an 710119 , China
| | - Hongtao Bian
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering , Shaanxi Normal University , Xi'an 710119 , China
| | - Yu Fang
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering , Shaanxi Normal University , Xi'an 710119 , China
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8
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Zhou D, Wei Q, Wang S, Li X, Bian H. Counterion Effect on Vibrational Relaxation and the Rotational Dynamics of Interfacial Water and an Anionic Vibrational Probe in the Confined Reverse Micelles Environment. J Phys Chem Lett 2019; 10:176-182. [PMID: 30582817 DOI: 10.1021/acs.jpclett.8b03389] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Vibrational relaxation and the rotational dynamics of water molecules encapsulated in reverse micelles (RMs) have been investigated by ultrafast infrared (IR) spectroscopy and two-dimensional IR (2D IR) spectroscopy. By changing the counterion of the hydrophilic headgroup in the RMs formed by Aerosol-OT (AOT) from Na+ to K+, Cs+ and Ca2+, we could determine the specific counterion effects on the rotational dynamics of water molecules. The orientational relaxation time constant of water decreases in the order Ca2+ > Na+ > K+ > Cs+. The SCN- anionic probe and counterion can form ion pairs at the interfacial region of the RMs. The rotational dynamics of SCN- anion significantly decreases because of the synergistic effects of confinement and the surface interactions in the interfacial region of the RMs. The results can provide a new understanding of the cationic Hofmeister effect at the molecular level observed in biological studies.
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Affiliation(s)
- Dexia Zhou
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering , Shaanxi Normal University , Xi'an , 710119 , China
| | - Qianshun Wei
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering , Shaanxi Normal University , Xi'an , 710119 , China
| | - Shuyan Wang
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering , Shaanxi Normal University , Xi'an , 710119 , China
| | - Xiaoqian Li
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering , Shaanxi Normal University , Xi'an , 710119 , China
| | - Hongtao Bian
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering , Shaanxi Normal University , Xi'an , 710119 , China
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9
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Blackshaw KJ, Varmecky MG, Patterson JD. Interfacial Structure and Partitioning of Nitrate Ions in Reverse Micelles. J Phys Chem A 2018; 123:336-342. [DOI: 10.1021/acs.jpca.8b09751] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- K. Jacob Blackshaw
- Department of Molecular Biology and Chemistry, Christopher Newport University, Newport News, Virginia 23606, United States
| | - Meredith G. Varmecky
- Department of Molecular Biology and Chemistry, Christopher Newport University, Newport News, Virginia 23606, United States
| | - Joshua D. Patterson
- Department of Molecular Biology and Chemistry, Christopher Newport University, Newport News, Virginia 23606, United States
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10
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Affiliation(s)
- Ward H. Thompson
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, USA
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11
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Modulation of probe-genomic DNA interaction within the confined interior of a reverse micelle: Is the bulk-like properties of water truly achieved in large reverse micelles? Int J Biol Macromol 2018; 118:1203-1210. [PMID: 29969635 DOI: 10.1016/j.ijbiomac.2018.06.180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Revised: 05/29/2018] [Accepted: 06/28/2018] [Indexed: 11/20/2022]
Abstract
The prime motivation of the present study is to explore the effect of reverse micellar confinement on the binding interaction of an anthracene-based probe 9-methyl anthroate with herring-sperm DNA. The structural modification of the genomic DNA from its native B-form to the non-native C-form and subsequently to the condensed Ψ-form as a function of the level of hydration (W0, defined as [water] / [surfactant]) of the reverse micellar core is found to reveal a remarkable regulatory role on the stability of the stacking interaction (intercalation) of the probe within the DNA helix; the interaction being progressively stabilized at higher W0. Particularly, a close perusal of the dynamical aspects of the interaction is found to be counter-intuitive to the popular notion of the properties of the confined water within the reverse micelles typically approaching bulk-like properties at sufficiently high hydration levels (W0 > 10).
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12
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Kundu K, Singh AP, Panda S, Singh V, Gardas RL, Senapati S. Study on the Conformation of Entrapped Protein inside the Reverse Micellar Confinement Based on the Amino Acid Derived Ionic Liquid. ChemistrySelect 2018. [DOI: 10.1002/slct.201800918] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Kaushik Kundu
- Department of Biotechnology; Bhupat and Jyoti Mehta School of Biosciences; Indian Institute of Technology Madras; Chennai 600036 India
| | - Akhil Pratap Singh
- Department of Biotechnology; Bhupat and Jyoti Mehta School of Biosciences; Indian Institute of Technology Madras; Chennai 600036 India
- Department of Chemistry; Indian Institute of Technology Madras; Chennai 600036 India
| | - Somenath Panda
- Department of Chemistry; Indian Institute of Technology Madras; Chennai 600036 India
| | - Vikram Singh
- Department of Chemistry; Indian Institute of Technology Madras; Chennai 600036 India
| | - Ramesh L. Gardas
- Department of Chemistry; Indian Institute of Technology Madras; Chennai 600036 India
| | - Sanjib Senapati
- Department of Biotechnology; Bhupat and Jyoti Mehta School of Biosciences; Indian Institute of Technology Madras; Chennai 600036 India
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13
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Fu J, Zhang L. Probing pH difference between micellar solution and nanoscale water within common black film by fluorescent dye. Chem Phys 2018. [DOI: 10.1016/j.chemphys.2018.02.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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14
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Sett R, Sen S, Paul BK, Guchhait N. How Does Nanoconfinement within a Reverse Micelle Influence the Interaction of Phenazinium-Based Photosensitizers with DNA? ACS OMEGA 2018; 3:1374-1385. [PMID: 31458466 PMCID: PMC6641382 DOI: 10.1021/acsomega.7b01820] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 01/17/2018] [Indexed: 06/10/2023]
Abstract
The major focus of the present work lies in exploring the influence of nanoconfinement within aerosol-OT (AOT) reverse micelles on the binding interaction of two phenazinium-based photosensitizers, namely, phenosafranin (PSF) and safranin-O (SO), with the DNA duplex. Circular dichroism and dynamic light-scattering studies reveal the condensation of DNA within the reverse micellar interior (transformation of the B-form of native DNA to ψ-form). Our results unveil a remarkable effect of the degree of hydration of the reverse micellar core on the stability of the stacking interaction (intercalation) of the drugs (PSF and SO) into DNA; increasing size of the water nanopool (that is, w 0) accompanies decreasing curvature of the DNA duplex structure with the consequent effect of increasing stabilization of the drug:DNA intercalation. The marked differences in the dynamical aspects of the interaction scenario following encapsulation within the reverse micellar core and the subsequent dependence on the size of the water nanopool are also meticulously explored. The differential degrees of steric interactions offered by the drug molecules (presence of methyl substitutions on the planar phenazinium ring in SO) are also found to affect the extent of intercalation of the drugs to DNA. In this context, it is imperative to state that the water pool of the reverse micellar core is often argued to approach bulk-like properties of water with increasing micellar size (typically w 0 ≥ 10), so that deviation from the bulk water properties is likely to be minimized in large reverse micelles (w 0 ≥ 10). On the contrary, our results (particularly quantitative elucidation of micropolarity and dynamical aspects of the interaction) explicitly demonstrate that the bulk-like behavior of the nanoconfined water is not truly achieved even in large reverse micelles.
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Affiliation(s)
- Riya Sett
- Department
of Chemistry, University of Calcutta, 92 A. P. C. Road, Kolkata 700009, India
| | - Swagata Sen
- Department
of Chemistry, University of Calcutta, 92 A. P. C. Road, Kolkata 700009, India
| | - Bijan K. Paul
- Department
of Chemistry, Mahadevananda Mahavidyalaya, Barrackpore, Kolkata 700120, India
| | - Nikhil Guchhait
- Department
of Chemistry, University of Calcutta, 92 A. P. C. Road, Kolkata 700009, India
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15
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Cui Y, Kuroda DG. Evidence of Molecular Heterogeneities in Amide-Based Deep Eutectic Solvents. J Phys Chem A 2018; 122:1185-1193. [DOI: 10.1021/acs.jpca.7b10264] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Yaowen Cui
- Department of Chemistry, Louisiana State University, Baton
Rouge, Louisiana 70803, United States
| | - Daniel G. Kuroda
- Department of Chemistry, Louisiana State University, Baton
Rouge, Louisiana 70803, United States
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16
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Biswas R, Bagchi B. Anomalous water dynamics at surfaces and interfaces: synergistic effects of confinement and surface interactions. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:013001. [PMID: 29205175 DOI: 10.1088/1361-648x/aa9b1d] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In nature, water is often found in contact with surfaces that are extended on the scale of molecule size but small on a macroscopic scale. Examples include lipid bilayers and reverse micelles as well as biomolecules like proteins, DNA and zeolites, to name a few. While the presence of surfaces and interfaces interrupts the continuous hydrogen bond network of liquid water, confinement on a mesoscopic scale introduces new features. Even when extended on a molecular scale, natural and biological surfaces often have features (like charge, hydrophobicity) that vary on the scale of the molecular diameter of water. As a result, many new and exotic features, which are not seen in the bulk, appear in the dynamics of water close to the surface. These different behaviors bear the signature of both water-surface interactions and of confinement. In other words, the altered properties are the result of the synergistic effects of surface-water interactions and confinement. Ultrafast spectroscopy, theoretical modeling and computer simulations together form powerful synergistic approaches towards an understanding of the properties of confined water in such systems as nanocavities, reverse micelles (RMs), water inside and outside biomolecules like proteins and DNA, and also between two hydrophobic walls. We shall review the experimental results and place them in the context of theory and simulations. For water confined within RMs, we discuss the possible interference effects propagating from opposite surfaces. Similar interference is found to give rise to an effective attractive force between two hydrophobic surfaces immersed and kept fixed at a separation of d, with the force showing an exponential dependence on this distance. For protein and DNA hydration, we shall examine a multitude of timescales that arise from frustration effects due to the inherent heterogeneity of these surfaces. We pay particular attention to the role of orientational correlations and modification of the same due to interaction with the surfaces.
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17
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Roy VP, Kubarych KJ. Interfacial Hydration Dynamics in Cationic Micelles Using 2D-IR and NMR. J Phys Chem B 2017; 121:9621-9630. [DOI: 10.1021/acs.jpcb.7b08225] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Ved Prakash Roy
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - Kevin J. Kubarych
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
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18
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Prototropism and dynamics of an anticancer drug in reverse micelles: Focus on the variation of pH in reverse micelles having w0≥ 10. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.08.076] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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19
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Orellano MS, Porporatto C, Silber JJ, Falcone RD, Correa NM. AOT reverse micelles as versatile reaction media for chitosan nanoparticles synthesis. Carbohydr Polym 2017; 171:85-93. [DOI: 10.1016/j.carbpol.2017.04.074] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 03/07/2017] [Accepted: 04/24/2017] [Indexed: 10/19/2022]
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20
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Kundu A, Verma PK, Cho M. Role of Solvent Water in the Temperature-Induced Self-Assembly of a Triblock Copolymer. J Phys Chem Lett 2017; 8:3040-3047. [PMID: 28613892 DOI: 10.1021/acs.jpclett.7b01008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Water-soluble triblock copolymers have received much attention in industrial applications and scientific fields. We here show that femtosecond mid-IR pump-probe spectroscopy is useful to study the role of water in the temperature-induced self-assembly of triblock copolymers. Our experimental results suggest two distinct subpopulations of water molecules: those that interact with other water molecules and those involved in the hydration of a triblock copolymer surface. We find that the vibrational dynamics of bulk-like water is not affected by either micellation or gelation of triblock copolymers. The increased population of water interacting with ether oxygen atoms of the copolymer during the unimer to micelle phase transition is important evidence for the entropic role of water in temperature-induced micelle formation at a low copolymer concentration. In contrast, at the critical gelation temperature and beyond, the population of surface-associated water molecules interacting with ether oxygen atoms decreases, which indicates important enthalpic control by water. The present study on the roles of water in the two different phase transitions of triblock copolymers sheds new light on the underlying mechanisms of temperature-induced self-aggregation behaviors of amphiphiles that are ubiquitous in nature.
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Affiliation(s)
- Achintya Kundu
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS) , Seoul 02841, Republic of Korea
- Department of Chemistry, Korea University , Seoul 02841, Republic of Korea
| | - Pramod Kumar Verma
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS) , Seoul 02841, Republic of Korea
- Department of Chemistry, Korea University , Seoul 02841, Republic of Korea
| | - Minhaeng Cho
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS) , Seoul 02841, Republic of Korea
- Department of Chemistry, Korea University , Seoul 02841, Republic of Korea
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21
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Burris PC, Laage D, Thompson WH. Simulations of the infrared, Raman, and 2D-IR photon echo spectra of water in nanoscale silica pores. J Chem Phys 2016; 144:194709. [DOI: 10.1063/1.4949766] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Paul C. Burris
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, USA
| | - Damien Laage
- Département de Chimie, Ecole Normale Supérieure-PSL Research University, 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
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22
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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.
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Affiliation(s)
- Cristian M O Lépori
- Departamento de Química, Universidad Nacional de Río Cuarto, Agencia Postal # 3, C.P. X5804BYA Río Cuarto, Argentina.
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23
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Sánchez-Lombardo I, Baruah B, Alvarez S, Werst KR, Segaline NA, Levinger NE, Crans DC. Size and shape trump charge in interactions of oxovanadates with self-assembled interfaces: application of continuous shape measure analysis to the decavanadate anion. NEW J CHEM 2016. [DOI: 10.1039/c5nj01788b] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Using 51V NMR spectroscopy, dynamic light scattering and continuous shape analysis to characterize two polyoxometalate-encapsulation in reverse micelles.
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Affiliation(s)
| | - Bharat Baruah
- Department of Chemistry
- Colorado State University
- Colorado 80523-1872
- USA
- Department of Chemistry
| | - Santiago Alvarez
- Departament de Química Inorganica
- Institut de Química Teorica i Computacional (IQTCUB)
- Universitat de Barcelona
- 08028 Barcelona
- Spain
| | - Katarina R. Werst
- Department of Chemistry
- Colorado State University
- Colorado 80523-1872
- USA
| | | | - Nancy E. Levinger
- Department of Chemistry
- Colorado State University
- Colorado 80523-1872
- USA
| | - Debbie C. Crans
- Department of Chemistry
- Colorado State University
- Colorado 80523-1872
- USA
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24
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Lee C, Nam D, Park S. Vibrational probing of the hydrogen-bond structure and dynamics of water in aqueous NaPF6 solutions. NEW J CHEM 2015. [DOI: 10.1039/c5nj00160a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The H-bond structures and dynamics of water in bulk and ionic hydration shells in aqueous NaPF6 solutions were measured at different NaPF6 concentrations.
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Affiliation(s)
- Chiho Lee
- Department of Chemistry
- Korea University
- Seoul 136-701
- Korea
| | - Dayoung Nam
- Department of Chemistry
- Korea University
- Seoul 136-701
- Korea
| | - Sungnam Park
- Department of Chemistry
- Korea University
- Seoul 136-701
- Korea
- Multidimensional Spectroscopy Laboratory
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25
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Koninti RK, Gavvala K, Sengupta A, Hazra P. Excited State Proton Transfer Dynamics of Topotecan Inside Biomimicking Nanocavity. J Phys Chem B 2014; 119:2363-71. [DOI: 10.1021/jp5066902] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Raj Kumar Koninti
- Department
of Chemistry, Indian Institute of Science Education and Research (IISER), Pune 411008, Maharashtra, India
| | - Krishna Gavvala
- Department
of Chemistry, Indian Institute of Science Education and Research (IISER), Pune 411008, Maharashtra, India
| | - Abhigyan Sengupta
- Department
of Chemistry, Indian Institute of Science Education and Research (IISER), Pune 411008, Maharashtra, India
| | - Partha Hazra
- Department
of Chemistry, Indian Institute of Science Education and Research (IISER), Pune 411008, Maharashtra, India
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26
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Lee J, Jeon J, Kim MS, Lee H, Cho M. Amide I IR probing of core and shell hydrogen-bond structures in reverse micelles. PURE APPL CHEM 2014. [DOI: 10.1515/pac-2014-5016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The properties of N-methylacetamide (NMA) molecules encapsulated in the reverse micelles (RMs) formed by anionic surfactant aerosol OT (AOT), are studied with vibrational spectroscopy and computation. Vibrational spectra of the amide I′ mode of the fully deuterated NMA-d7 show gradual increase of peak frequencies and line broadening as the size of RMs decreases. Analyses of the spectral features reveal the presence of three states of NMA-d7 that correspond to NMA located in the core of water phase (absorption frequency of 1606 cm–1) and two types of interfacial NMA near the surfactant layer (1620 and 1644 cm–1). In larger RMs with water content w0 = [D2O]/[AOT] ≥ 10, only the first two states are observed, whereas in smaller RMs, the population of the third state grows up to 25 % at w0 = 2. These results indicate the general validity of the two-state core/shell model for the confined aqueous solution of NMA, with small modifications due to the system-dependent solute-interface interaction. However, simulations of small RM systems with w0 ≤ 15 show continuous variations of the population, frequency shifts, and the solute-solvent interaction strengths at solute-interface distance less than 4 Å. Thus, the distinction of solute core/shell states tends to be blurred in small RMs but is still effective in interpreting the average spectroscopic observables.
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27
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28
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A facile synthesis of high optical quality silver nanoparticles by ascorbic acid reduction in reverse micelles at room temperature. J Colloid Interface Sci 2014; 413:37-42. [DOI: 10.1016/j.jcis.2013.09.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 08/29/2013] [Accepted: 09/03/2013] [Indexed: 11/21/2022]
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29
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Soper AK. Radical re-appraisal of water structure in hydrophilic confinement. Chem Phys Lett 2013; 590:1-15. [PMID: 25843963 PMCID: PMC4376068 DOI: 10.1016/j.cplett.2013.10.075] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 10/22/2013] [Indexed: 11/29/2022]
Abstract
The structure of water confined in MCM41 silica cylindrical pores is studied to determine whether confined water is simply a version of the bulk liquid which can be substantially supercooled without crystallisation. A combination of total neutron scattering from the porous silica, both wet and dry, and computer simulation using a realistic model of the scattering substrate is used. The water in the pore is divided into three regions: core, interfacial and overlap. The average local densities of water in these simulations are found to be about 20% lower than bulk water density, while the density in the core region is below, but closer to, the bulk density. There is a decrease in both local and core densities when the temperature is lowered from 298 K to 210 K. The radical proposal is made here that water in hydrophilic confinement is under significant tension, around -100 MPa, inside the pore.
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30
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Maity A, Das S, Ghosh P, Das T, Seth SK, Mondal S, Gupta P, Purkayastha P. Dynamics of pyrenesemicarbazide and pyrenethiosemicarbazide in reverse micelle of AOT in n-heptane: Probing critical penetration of water molecules toward the palisade. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2013.09.055] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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31
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Zhao Y. Cooperatively enhanced receptors for biomimetic molecular recognition. Chemphyschem 2013; 14:3878-85. [PMID: 24151236 DOI: 10.1002/cphc.201300744] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 08/22/2013] [Indexed: 11/06/2022]
Abstract
The concept of preorganization suggests that organizing a receptor around its guest during binding is detrimental, because the cost of conformational change is assumed to be paid out of the binding energy. Although this concept has historically guided the synthesis of a great many synthetic hosts, in recent years, chemists have begun to synthesize receptors that resemble proteins in their cooperative conformational changes. Such changes could enhance the host-guest interactions, in particular if the binding of the guest triggers previously unengaged noncovalent interactions within the host. These hosts, referred to as cooperatively enhanced receptors, corroborate with their biological counterparts to support the approach of creating high-affinity receptors through the combined strategies of cooperativity and preorganization. Solvents, often the invisible participants of any solution-based supramolecular process, should be properly considered in the design of synthetic receptors, whether preorganized or cooperatively enhanced.
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Affiliation(s)
- Yan Zhao
- Department of Chemistry, Iowa State University, Ames, Iowa 50011-3111 (USA), Fax: (+1) 515-294-5845.
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32
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Biswas R, Furtado J, Bagchi B. Layerwise decomposition of water dynamics in reverse micelles: A simulation study of two-dimensional infrared spectrum. J Chem Phys 2013; 139:144906. [DOI: 10.1063/1.4824446] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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33
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Uskoković V. Revisiting the Fundamentals in the Design and Control of Nanoparticulate Colloids in the Frame of Soft Chemistry. REVIEW JOURNAL OF CHEMISTRY 2013; 3:271-303. [PMID: 24490052 PMCID: PMC3906689 DOI: 10.1134/s2079978013040031] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This review presents thoughts on some of the fundamental features of conceptual models applied in the design of fine particles in the frames of colloid and soft chemistry. A special emphasis is placed on the limitations of these models, an acknowledgment of which is vital in improving their intricacy and effectiveness in predicting the outcomes of the corresponding experimental settings. Thermodynamics of self-assembly phenomena illustrated on the examples of protein assembly and micellization is analyzed in relation to the previously elaborated thesis that each self-assembly in reality presents a co-assembly, since it implies a mutual reorganization of the assembling system and its immediate environment. Parameters used in the design of fine particles by precipitation are discussed while referring to solubility product, various measures of supersaturation levels, induction time, nucleation and crystal growth rates, interfacial energies, and the Ostwald-Lussac law of phases. Again, the main drawbacks and inadequacies of using the aforementioned parameters in tailoring the materials properties in a soft and colloidal chemical setting were particularly emphasized. The basic and practical limitations of zeta-potential analyses, routinely used to stabilize colloidal dispersions and initiate specific interactions between soft chemical entities, were also outlined. The final section of the paper reiterates the unavoidable presence of practical qualitative models in the design and control of nanoparticulate colloids, which is supported by the overwhelming complexity of quantitative relationships that govern the processes of their formation and assembly.
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Affiliation(s)
- Vuk Uskoković
- Therapeutic Micro and Nanotechnology Laboratory, Department of Bioengineering and Therapeutic Sciences, University of California, 1700 4th Street, QB3 204, Mission Bay Campus, San Francisco, CA 94158-2330707, USA
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34
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Bakulin AA, Cringus D, Pieniazek PA, Skinner JL, Jansen TLC, Pshenichnikov MS. Dynamics of water confined in reversed micelles: multidimensional vibrational spectroscopy study. J Phys Chem B 2013; 117:15545-58. [PMID: 23980543 DOI: 10.1021/jp405853j] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Here we perform a comprehensive study of ultrafast molecular and vibrational dynamics of water confined in small reversed micelles (RMs). The molecular picture is elucidated with two-dimensional infrared (2D IR) spectroscopy of water OH stretch vibrations and molecular dynamics simulations, bridged by theoretical calculations of linear and 2D IR vibrational spectra. To investigate the effects of intermolecular coupling, experiments and modeling are performed for isotopically diluted (HDO in D2O) and undiluted (H2O) water. We put a separation of water inside RMs into two subensembles (water-bound and surfactant-bound molecules), observed by many before, on a solid theoretical basis. Water molecules fully attached to the lipid interface ("shell" water) are decoupled from one another and from the central water nanopool ("core" water). The environmental fluctuations are largely "frozen" for the shell water, while the core waters demonstrate much faster dynamics but still not as fast as in the bulk case. A substantial nanoconfinement effect on the dynamics of the core water is observed after disentanglement of the shell water contribution, which is fully confirmed by the simulations of 2D IR spectra. Current results provide new insights into interaction between biological objects like membranes or proteins with the surrounding aqueous bath, and highlight peculiarities in vibrational energy redistribution near the lipid surface.
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Affiliation(s)
- Artem A Bakulin
- Zernike Institute for Advanced Materials, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
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35
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Singh PK, Kuroda DG, Hochstrasser RM. An ion's perspective on the molecular motions of nanoconfined water: a two-dimensional infrared spectroscopy study. J Phys Chem B 2013; 117:9775-84. [PMID: 23855349 DOI: 10.1021/jp406725a] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The vibrational population relaxation and hydration shell dynamics of the symmetric tricyanomethanide (TCM) anion are investigated in a sodium bis(2-ethylhexyl)sulfosuccinate reverse micelle as a function of the water pool radius. Two-dimensional infrared (IR) spectroscopy in combination with linear absorption and ultrafast IR pump-probe spectroscopy is utilized in this study. Spectroscopic measurements show that the anion has two bands in the 2160-2175 cm(-1) region, each with its own spectroscopic signatures. Analysis of the vibrational dynamics shows that the two vibrational bands are consistent with the anion located either at the interface or in the water pool. The sensitivity of the TCM anion to the environment allows us to unequivocally monitor the vibrational and hydration dynamics of the anion in those two different environments. A TCM anion located at the interface does not show any significant variation of the vibrational dynamics with the water pool size. On the contrary, the TCM anion inside the water pool exhibits a large and nonlinear variation of the vibrational lifetime and the frequency-frequency correlation time with the pool radius. Moreover, for the solvated anion in water pools of 49 Å in radius (W0 = 30), the vibrational lifetime reaches the values observed for the anion in bulk water while the frequency-frequency correlation time shows a characteristic time higher than that observed in the bulk. In addition, for the first time a model is developed and used to explain the observed nonlinear variation of the spectroscopic observables with the pool size. This model attributes the changes in the vibrational dynamics of the TCM anion in the water pool to the slow and radius-dependent water dynamics present in the confined environment of a reverse micelle.
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Affiliation(s)
- Prabhat K Singh
- Ultrafast Optical Processes Laboratory, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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36
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Reverse micelles as a tool for probing solvent modulation of protein dynamics: Reverse micelle encapsulated hemoglobin. Chem Phys 2013; 430:88-97. [PMID: 24039330 DOI: 10.1016/j.chemphys.2013.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Hydration waters impact protein dynamics. Dissecting the interplay between hydration waters and dynamics requires a protein that manifests a broad range of dynamics. Proteins in reverse micelles (RMs) have promise as tools to achieve this objective because the water content can be manipulated. Hemoglobin is an appropriate tool with which to probe hydration effects. We describe both a protocol for hemoglobin encapsulation in reverse micelles and a facile method using PEG and cosolvents to manipulate water content. Hydration properties are probed using the water-sensitive fluorescence from Hb bound pyranine and covalently attached Badan. Protein dynamics are probed through ligand recombination traces derived from photodissociated carbonmonoxy hemoglobin on a log scale that exposes the potential role of both α and β solvent fluctuations in modulating protein dynamics. The results open the possibility of probing hydration level phenomena in this system using a combination of NMR and optical probes.
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37
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Biswas R, Chakraborti T, Bagchi B, Ayappa KG. Non-monotonic, distance-dependent relaxation of water in reverse micelles: Propagation of surface induced frustration along hydrogen bond networks. J Chem Phys 2012; 137:014515. [DOI: 10.1063/1.4732095] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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38
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Correa NM, Silber JJ, Riter RE, Levinger NE. Nonaqueous Polar Solvents in Reverse Micelle Systems. Chem Rev 2012; 112:4569-602. [DOI: 10.1021/cr200254q] [Citation(s) in RCA: 204] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- N. Mariano Correa
- Departamento de Química, Universidad Nacional de Río Cuarto, Agencia
Postal #3, C.P. X5804BYA Río Cuarto, Argentina
| | - Juana J. Silber
- Departamento de Química, Universidad Nacional de Río Cuarto, Agencia
Postal #3, C.P. X5804BYA Río Cuarto, Argentina
| | - Ruth E. Riter
- Department of Chemistry, Agnes Scott College, Decatur, Georgia 30030-3770, United
States
| | - Nancy E. Levinger
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872,
United States
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39
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Setua P, Ghatak C, Rao VG, Das SK, Sarkar N. Dynamics of Solvation and Rotational Relaxation of Coumarin 480 in Pure Aqueous-AOT Reverse Micelle and Reverse Micelle Containing Different-Sized Silver Nanoparticles Inside Its Core: A Comparative Study. J Phys Chem B 2012; 116:3704-12. [PMID: 22380919 DOI: 10.1021/jp203043k] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Palash Setua
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, West
Bengal, India
| | - Chiranjib Ghatak
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, West
Bengal, India
| | - Vishal Govind Rao
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, West
Bengal, India
| | - S. K. Das
- Variable Energy Cyclotron Centre, 1/AF, Bidhan Nagar,
Kolkata 700064, West Bengal, India
| | - Nilmoni Sarkar
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, West
Bengal, India
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40
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Fenn EE, Fayer MD. Extracting 2D IR frequency-frequency correlation functions from two component systems. J Chem Phys 2011; 135:074502. [PMID: 21861571 DOI: 10.1063/1.3625278] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The center line slope (CLS) method is often used to extract the frequency-frequency correlation function (FFCF) from 2D IR spectra to delineate dynamics and to identify homogeneous and inhomogeneous contributions to the absorption line shape of a system. While the CLS method is extremely efficient, quite accurate, and immune to many experimental artifacts, it has only been developed and properly applied to systems that have a single vibrational band, or to systems of two species that have spectrally resolved absorption bands. In many cases, the constituent spectra of multiple component systems overlap and cannot be distinguished from each other. This situation creates ambiguity when analyzing 2D IR spectra because dynamics for different species cannot be separated. Here a mathematical formulation is presented that extends the CLS method for a system consisting of two components (chemically distinct uncoupled oscillators). In a single component system, the CLS corresponds to the time-dependent portion of the normalized FFCF. This is not the case for a two component system, as a much more complicated expression arises. The CLS method yields a series of peak locations originating from slices taken through the 2D spectra. The slope through these peak locations yields the CLS value for the 2D spectra at a given T(w). We derive analytically that for two component systems, the peak location of the system can be decomposed into a weighted combination of the peak locations of the constituent spectra. The weighting depends upon the fractional contribution of each species at each wavelength and also on the vibrational lifetimes of both components. It is found that an unknown FFCF for one species can be determined as long as the peak locations (referred to as center line data) of one of the components are known, as well as the vibrational lifetimes, absorption spectra, and other spectral information for both components. This situation can arise when a second species is introduced into a well characterized single species system. An example is a system in which water exists in bulk form and also as water interacting with an interface. An algorithm is presented for back-calculating the unknown FFCF of the second component. The accuracy of the algorithm is tested with a variety of model cases in which all components are initially known. The algorithm successfully reproduces the FFCF for the second component within a reasonable degree of error.
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Affiliation(s)
- Emily E Fenn
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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41
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Milischuk AA, Ladanyi BM. Structure and dynamics of water confined in silica nanopores. J Chem Phys 2011; 135:174709. [DOI: 10.1063/1.3657408] [Citation(s) in RCA: 148] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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42
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Fenn EE, Wong DB, Giammanco CH, Fayer MD. Dynamics of Water at the Interface in Reverse Micelles: Measurements of Spectral Diffusion with Two-Dimensional Infrared Vibrational Echoes. J Phys Chem B 2011; 115:11658-70. [DOI: 10.1021/jp206903k] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Emily E. Fenn
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Daryl B. Wong
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Chiara H. Giammanco
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - M. D. Fayer
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
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43
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Fenn EE, Wong DB, Fayer MD. Water dynamics in small reverse micelles in two solvents: two-dimensional infrared vibrational echoes with two-dimensional background subtraction. J Chem Phys 2011; 134:054512. [PMID: 21303143 DOI: 10.1063/1.3532542] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Water dynamics as reflected by the spectral diffusion of the water hydroxyl stretch were measured in w(0) = 2 (1.7 nm diameter) Aerosol-OT (AOT)/water reverse micelles in carbon tetrachloride and in isooctane solvents using ultrafast 2D IR vibrational echo spectroscopy. Orientational relaxation and population relaxation are observed for w(0) = 2, 4, and 7.5 in both solvents using IR pump-probe measurements. It is found that the pump-probe observables are sensitive to w(0), but not to the solvent. However, initial analysis of the vibrational echo data from the water nanopool in the reverse micelles in the isooctane solvent seems to yield different dynamics than the CCl(4) system in spite of the fact that the spectra, vibrational lifetimes, and orientational relaxation are the same in the two systems. It is found that there are beat patterns in the interferograms with isooctane as the solvent. The beats are observed from a signal generated by the AOT/isooctane system even when there is no water in the system. A beat subtraction data processing procedure does a reasonable job of removing the distortions in the isooctane data, showing that the reverse micelle dynamics are the same within experimental error regardless of whether isooctane or carbon tetrachloride is used as the organic phase. Two time scales are observed in the vibrational echo data, ~1 and ~10 ps. The slower component contains a significant amount of the total inhomogeneous broadening. Physical arguments indicate that there is a much slower component of spectral diffusion that is too slow to observe within the experimental window, which is limited by the OD stretch vibrational lifetime.
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Affiliation(s)
- Emily E Fenn
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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44
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Chowdhary J, Ladanyi BM. Molecular simulation study of water mobility in aerosol-OT reverse micelles. J Phys Chem A 2011; 115:6306-16. [PMID: 21548627 DOI: 10.1021/jp201866t] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In this work, we present results from molecular dynamics simulations on the single-molecule relaxation of water within reverse micelles (RMs) of different sizes formed by the surfactant aerosol-OT (AOT, sodium bis(2-ethylhexyl)sulfosuccinate) in isooctane. Results are presented for RM water content w(0) = [H(2)O]/[AOT] in the range from 2.0 to 7.5. We show that translational diffusion of water within the RM can, to a good approximation, be decoupled from the translation of the RM through the isooctane solvent. Water translational mobility within the RM is restricted by the water pool dimensions, and thus, the water mean-squared displacements (MSDs) level off in time. Comparison with models of diffusion in confined geometries shows that a version of the Gaussian confinement model with a biexponential decay of correlations provides a good fit to the MSDs, while a model of free diffusion within a sphere agrees less well with simulation results. We find that the local diffusivity is considerably reduced in the interfacial region, especially as w(0) decreases. Molecular orientational relaxation is monitored by examining the behavior of OH and dipole vectors. For both vectors, orientational relaxation slows down close to the interface and as w(0) decreases. For the OH vector, reorientation is strongly affected by the presence of charged species at the RM interface and these effects are especially pronounced for water molecules hydrogen-bonded to surfactant sites that serve as hydrogen-bond acceptors. For the dipole vector, orientational relaxation near the interface slows down more than that for the OH vector due mainly to the influence of ion-dipole interactions with the sodium counterions. We investigate water OH and dipole reorientation mechanisms by studying the w(0) and interfacial shell dependence of orientational time correlations for different Legendre polynomial orders.
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Affiliation(s)
- Janamejaya Chowdhary
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, USA
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45
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Affiliation(s)
- Alberto Striolo
- School of Chemical, Biological and Materials Engineering, University of Oklahoma, Norman, OK 73019, U.S.A
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46
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Lee KK, Park KH, Kwon D, Choi JH, Son H, Park S, Cho M. Ion-pairing dynamics of Li+ and SCN− in dimethylformamide solution: Chemical exchange two-dimensional infrared spectroscopy. J Chem Phys 2011; 134:064506. [DOI: 10.1063/1.3552961] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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47
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Abramczyk H, Brozek-Pluska B, Surmacki J, Jablonska-Gajewicz J, Kordek R. Hydrogen bonds of interfacial water in human breast cancer tissue compared to lipid and DNA interfaces. ACTA ACUST UNITED AC 2011. [DOI: 10.4236/jbpc.2011.22020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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48
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Rosenfeld DE, Schmuttenmaer CA. Dynamics of the Water Hydrogen Bond Network at Ionic, Nonionic, and Hydrophobic Interfaces in Nanopores and Reverse Micelles. J Phys Chem B 2010; 115:1021-31. [PMID: 21182316 DOI: 10.1021/jp109599q] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Daniel E. Rosenfeld
- Department of Chemistry, Yale University, 225 Prospect Street, P.O. Box 208107, New Haven, Connecticut 06520-8107, United States
| | - Charles A. Schmuttenmaer
- Department of Chemistry, Yale University, 225 Prospect Street, P.O. Box 208107, New Haven, Connecticut 06520-8107, United States
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49
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Vodolazkaya NA, Mchedlov-Petrossyan NO, Salamanova NV, Surov YN, Doroshenko AO. Molecular spectroscopy studies of solvent properties of dispersed ‘water pools’: Fluorescein and 2,7-dichlorofluorescein in reversed AOT-based microemulsions. J Mol Liq 2010. [DOI: 10.1016/j.molliq.2010.08.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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50
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Biswas R, Bagchi B. A kinetic Ising model study of dynamical correlations in confined fluids: Emergence of both fast and slow time scales. J Chem Phys 2010; 133:084509. [DOI: 10.1063/1.3474948] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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