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Blach D, Girardi VR, Silber JJ, Correa NM, Falcone RD. How the type of interface can alter the behavior of an aprotic ionic liquid-water mixture entrapped in different reverse micelles. An exploratory study using an enzymatic reaction as a sensor. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.129812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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2
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Monitoring the microenvironment inside polymeric micelles using the fluorescence probe 6-propionyl-2-dimethylaminonaphthalene (PRODAN). J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.117552] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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3
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Dib N, Girardi VR, Silber JJ, Correa NM, Falcone RD. How the external solvent in biocompatible reverse micelles can improve the alkaline phosphatase behavior. Org Biomol Chem 2021; 19:4969-4977. [PMID: 34002175 DOI: 10.1039/d0ob02371j] [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
In the last decade, the nature of the nonpolar solvents that can be part of reverse micelles (RMs) has been the topic of several investigations to improve their applications. In this sense, the hydrolysis of 1-naphthyl phosphate catalyzed by the enzyme alkaline phosphatase (AP) was used as a probe to investigate the effect of the change of the external solvent on RMs formulated with the anionic surfactant sodium diethylhexyl sulfosuccinate (AOT). As external nonpolar solvents, two biocompatible lipophilic esters, isopropyl myristate and methyl laurate, and the traditional nonpolar solvents, n-heptane and benzene, were used. The results were compared among the RMs investigated and with the reaction in homogeneous media. Thus, the effect of the nanoconfinement as well as the impact of the replacement of a conventional external nonpolar solvent by biocompatible solvents were analyzed. The results indicate that the catalytic efficiency in the AOT RMs is larger than that in homogeneous media, denoting a different hydration level over the AP enzyme, which is directly related to the different degrees of nonpolar solvent penetration to the RM interface. Our findings demonstrated that toxic solvents such as n-heptane and benzene can be replaced by nontoxic ones (isopropyl myristate or methyl laurate) in AOT RMs without affecting the performance of micellar systems as nanoreactors, making them a green and promising alternative toward efficient and sustainable chemistry.
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Affiliation(s)
- Nahir Dib
- Departamento de Química, Universidad Nacional de Rio Cuarto, Agencia Postal 3, C.P. X5804BYA, Ruta Nacional 36, km 601, Rio Cuarto, Córdoba, Argentina and Instituto de Desarrollo Agroindustrial y de la Salud (IDAS), Universidad Nacional de Río Cuarto, Agencia Postal 3, C.P. X5804BYA, Ruta Nacional 36, km 601, Río Cuarto, Córdoba, Argentina.
| | - Valeria R Girardi
- Departamento de Química, Universidad Nacional de Rio Cuarto, Agencia Postal 3, C.P. X5804BYA, Ruta Nacional 36, km 601, Rio Cuarto, Córdoba, Argentina
| | - Juana J Silber
- Departamento de Química, Universidad Nacional de Rio Cuarto, Agencia Postal 3, C.P. X5804BYA, Ruta Nacional 36, km 601, Rio Cuarto, Córdoba, Argentina and Instituto de Desarrollo Agroindustrial y de la Salud (IDAS), Universidad Nacional de Río Cuarto, Agencia Postal 3, C.P. X5804BYA, Ruta Nacional 36, km 601, Río Cuarto, Córdoba, Argentina.
| | - N Mariano Correa
- Departamento de Química, Universidad Nacional de Rio Cuarto, Agencia Postal 3, C.P. X5804BYA, Ruta Nacional 36, km 601, Rio Cuarto, Córdoba, Argentina and Instituto de Desarrollo Agroindustrial y de la Salud (IDAS), Universidad Nacional de Río Cuarto, Agencia Postal 3, C.P. X5804BYA, Ruta Nacional 36, km 601, Río Cuarto, Córdoba, Argentina.
| | - R Dario Falcone
- Departamento de Química, Universidad Nacional de Rio Cuarto, Agencia Postal 3, C.P. X5804BYA, Ruta Nacional 36, km 601, Rio Cuarto, Córdoba, Argentina and Instituto de Desarrollo Agroindustrial y de la Salud (IDAS), Universidad Nacional de Río Cuarto, Agencia Postal 3, C.P. X5804BYA, Ruta Nacional 36, km 601, Río Cuarto, Córdoba, Argentina.
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Gutierrez JA, Silber JJ, Falcone RD, Correa NM. Modified reverse micelle method as facile way to obtain several gold nanoparticle morphologies. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.115709] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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5
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Role of micellar interface in the synthesis of chitosan nanoparticles formulated by reverse micellar method. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2020.124876] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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6
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Smortsova Y, Miannay FA, Koverga V, Dubois J, Kalugin O, Idrissi A. Fluorescent probe dependence of the solvation dynamics in ionic liquid BmimBF4 and propylene carbonate mixtures: a time-resolved fluorescence and quantum chemistry study. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.02.123] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Villa CC, Correa NM, Silber JJ, Falcone RD. Catanionic Reverse Micelles as an Optimal Microenvironment To Alter the Water Electron Donor Capacity in a S N2 Reaction. J Org Chem 2019; 84:1185-1191. [PMID: 30608687 DOI: 10.1021/acs.joc.8b02492] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The effect of interfacial water entrapped in two types of catanionic reverse micelles (RMs) on the kinetic parameters of the SN2 reaction between dimethyl-4-nitrophenylsulfonium trifluoromethanesulfonate (S+) and n-butylamine (BuNH2) was explored. Two catanionic surfactants, composed of a mixture of oppositely charged ionic surfactants without their original counterions, were used to create the RMs. Thus, benzyl- n-hexadecyldimethylammonium 1,4-bis(2-ethylhexyl) sulfosuccinate (BHD-AOT) and cetyltrimethylammonium 1,4-bis(2-ethylhexyl) sulfosuccinate (CTA-AOT) were formed. Also, the well-known anionic surfactant sodium 1,4-bis(2-ethylhexyl) sulfosuccinate (Na-AOT) was employed as a comparison. Our results showed an important catalytic-like effect of all RMs investigated in comparison with a water-benzene mixture, and the rate constant values depend on the type of surfactant used. Faster reaction in BHD-AOT RMs than in CTA-AOT and Na-AOT RMs was observed. This behavior was attributed to the strong interaction (by hydrogen bonding with AOT anion and ion-dipole interaction with BHD+) between the entrapped water and the BHD-AOT interface, which reduces the solvation capacity of water on S+. In CTA-AOT (and Na-AOT) RMs, the water-interface interaction is weaker and the electron pairs of water can solvate S+ ions. In summary, the chemical structure of the counterion on the catanionic surfactant alters the interfacial region, allowing the progress of a reaction inside the RMs to be controlled.
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Affiliation(s)
- Cristian C Villa
- Programa de Química , Universidad del Quindío , Carrera 15 Calle 14 Norte C.P. 630004 Armenia , Colombia
| | - 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
| | - R Dario Falcone
- Departamento de Química , Universidad Nacional de Río Cuarto , Agencia Postal # 3 C.P. X5804BYA Río Cuarto , Argentina
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Chen T, Lee SW, Abelt CJ. 1,5-Prodan Emits from a Planar Intramolecular Charge-Transfer Excited State. ACS OMEGA 2018; 3:4816-4823. [PMID: 31458698 PMCID: PMC6641964 DOI: 10.1021/acsomega.8b00423] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 04/20/2018] [Indexed: 06/10/2023]
Abstract
1-Propionyl-5-dimethylaminonaphthalene (8, 1,5-Prodan) and two derivatives where the amino group is constrained in a seven-membered (9) and five-membered (10) ring are prepared. All three exhibit strong fluorescence and similar degrees of solvatochromism. Their fluorescence is strongly quenched in alcohol solvents. Because the amino group in 9 and especially 10 is forced to be coplanar with the naphthalene ring, the similar photophysical behavior of all three suggests that emission arises from a planar excited state (planar intramolecular charge transfer).
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Beniwal V, Kumar A, Pal H, Dutta Choudhury S. Excited-state prototropism of 7-hydroxy-4-methylcoumarin in [Cnmim][BF4] series of ionic liquid–water mixtures: insights on reverse micelle-like water nanocluster formation. Photochem Photobiol Sci 2018; 17:1256-1266. [DOI: 10.1039/c8pp00132d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This study explores the excited-state prototropic behavior of 7-hydroxy-4-methylcoumarin dye in ionic liquid–water media, to reveal the intriguing reverse micelle formation in these solvent systems.
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Affiliation(s)
- Vijay Beniwal
- Physical and Materials Chemistry Division
- CSIR-National Chemical Laboratory
- Pune-411 008
- India
| | - Anil Kumar
- Physical and Materials Chemistry Division
- CSIR-National Chemical Laboratory
- Pune-411 008
- India
| | - Haridas Pal
- Radiation & Photochemistry Division
- Bhabha Atomic Research Centre
- Mumbai 400 085
- India
- Home Bhabha National Institute
| | - Sharmistha Dutta Choudhury
- Radiation & Photochemistry Division
- Bhabha Atomic Research Centre
- Mumbai 400 085
- India
- Home Bhabha National Institute
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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.
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11
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Crosio MA, Silber JJ, Moyano F, Correa NM, Falcone RD. The Use of AOBH-DEHP Molecular Probe to Characterize BHDC Reverse Micelles Interfaces. Insights on the Interfacial Water Structure. ChemistrySelect 2017. [DOI: 10.1002/slct.201700361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Matías A. Crosio
- Departamento de Química; Universidad Nacional de Río Cuarto, Agencia Postal # 3. ( X5804ZAB ); Río Cuarto Argentina
| | - Juana J. Silber
- Departamento de Química; Universidad Nacional de Río Cuarto, Agencia Postal # 3. ( X5804ZAB ); Río Cuarto Argentina
| | - Fernando Moyano
- Departamento de Química; Universidad Nacional de Río Cuarto, Agencia Postal # 3. ( X5804ZAB ); Río Cuarto Argentina
| | - N. Mariano Correa
- Departamento de Química; Universidad Nacional de Río Cuarto, Agencia Postal # 3. ( X5804ZAB ); Río Cuarto Argentina
| | - R. Darío Falcone
- Departamento de Química; Universidad Nacional de Río Cuarto, Agencia Postal # 3. ( X5804ZAB ); Río Cuarto Argentina
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Lépori CMO, Silber JJ, Falcone RD, Correa NM. Improvement of the amphiphilic properties of a dialkyl phosphate by creation of a protic ionic liquid-like surfactant. RSC Adv 2017. [DOI: 10.1039/c7ra08907d] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Imim-DEHP, an interesting protic IL-like surfactant to create RMs in aliphatic and aromatic non-polar solvents and unilamellar vesicles in water.
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Affiliation(s)
- Cristian M. O. Lépori
- Departamento de Química
- Universidad Nacional de Río Cuarto
- C.P. X5804BYA Río Cuarto
- Argentina
| | - Juana J. Silber
- Departamento de Química
- Universidad Nacional de Río Cuarto
- C.P. X5804BYA Río Cuarto
- Argentina
| | - R. Darío Falcone
- Departamento de Química
- Universidad Nacional de Río Cuarto
- C.P. X5804BYA Río Cuarto
- Argentina
| | - N. Mariano Correa
- Departamento de Química
- Universidad Nacional de Río Cuarto
- C.P. X5804BYA Río Cuarto
- Argentina
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14
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Agazzi FM, Falcone RD, Silber JJ, Correa NM. Non-aqueous reverse micelles created with a cationic surfactant: Encapsulating ethylene glycol in BHDC/non-polar solvent blends. Colloids Surf A Physicochem Eng Asp 2016. [DOI: 10.1016/j.colsurfa.2016.09.070] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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15
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Abel S, Galamba N, Karakas E, Marchi M, Thompson WH, Laage D. On the Structural and Dynamical Properties of DOPC Reverse Micelles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:10610-10620. [PMID: 27649391 DOI: 10.1021/acs.langmuir.6b02566] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The structure and dynamics of phospholipid reverse micelles are studied by molecular dynamics. We report all-atom unconstrained simulations of 1,2-dioleoyl-sn-phosphatidylcholine (DOPC) reverse micelles in benzene of increasing sizes, with water-to-surfactant number ratios ranging from W0 = 1 to 16. The aggregation number, i.e., the number of DOPC molecules per reverse micelle, is determined to fit experimental light-scattering measurements of the reverse micelle diameter. The simulated reverse micelles are found to be approximately spherical. Larger reverse micelles (W0 > 4) exhibit a layered structure with a water core and the hydration structure of DOPC phosphate head groups is similar to that found in phospholipid membranes. In contrast, the structure of smaller reverse micelles (W0 ≤ 4) cannot be described as a series of concentric layers successively containing water, surfactant head groups, and surfactant tails, and the head groups are only partly hydrated and frequently present in the core. The dynamics of water molecules within the phospholipid reverse micelles slow down as the reverse micelle size decreases, in agreement with prior studies on AOT and Igepal reverse micelles. However, the average water reorientation dynamics in DOPC reverse micelles is found to be much slower than in AOT and Igepal reverse micelles with the same W0 ratio. This is explained by the smaller water pool and by the stronger interactions between water and the charged head groups, as confirmed by the red-shift of the computed infrared line shape with decreasing W0.
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Affiliation(s)
- Stéphane Abel
- Commissariat à l'Energie Atomique et aux Energies Alternatives, DRF/iBiTEC-S/SB2SM & CNRS UMR 9198, 91191 Saclay, France
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, F-91198 Cedex Gif-sur-Yvette, France
| | - Nuno Galamba
- Ecole 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
| | - Esra Karakas
- Commissariat à l'Energie Atomique et aux Energies Alternatives, DRF/iBiTEC-S/SB2SM & CNRS UMR 9198, 91191 Saclay, France
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, F-91198 Cedex Gif-sur-Yvette, France
- Maison de la Simulation, USR 3441, CEA-CNRS-INRIA-Univ Paris Sud - Univ Versailles, 91191 Cedex Gif-sur-Yvette, France
| | - Massimo Marchi
- Commissariat à l'Energie Atomique et aux Energies Alternatives, DRF/iBiTEC-S/SB2SM & CNRS UMR 9198, 91191 Saclay, France
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, F-91198 Cedex Gif-sur-Yvette, France
| | - Ward H Thompson
- Department of Chemistry, University of Kansas , Lawrence, Kansas 66045, United States
| | - Damien Laage
- Ecole 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
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Luna MA, Correa NM, Silber JJ, Falcone RD, Moyano F. Properties of AOT reverse micelle interfaces with different polar solvents. J PHYS ORG CHEM 2016. [DOI: 10.1002/poc.3535] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- M. Alejandra Luna
- Departamento de Química; Universidad Nacional de Río Cuarto; Agencia Postal # 3. C.P. X5804BYA Río Cuarto Argentina
| | - 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
| | - R. Dario Falcone
- Departamento de Química; Universidad Nacional de Río Cuarto; Agencia Postal # 3. C.P. X5804BYA Río Cuarto Argentina
| | - Fernando Moyano
- Departamento de Química; Universidad Nacional de Río Cuarto; Agencia Postal # 3. C.P. X5804BYA Río Cuarto Argentina
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17
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Cuenca VE, Falcone RD, Silber JJ, Correa NM. How the Type of Cosurfactant Impacts Strongly on the Size and Interfacial Composition in Gemini 12-2-12 RMs Explored by DLS, SLS, and FTIR Techniques. J Phys Chem B 2016; 120:467-76. [DOI: 10.1021/acs.jpcb.5b10380] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Victor E. Cuenca
- Departamento de Química, Universidad Nacional de Río Cuarto, Agencia Postal # 3. C.P., X5804BYA Río Cuarto, Argentina
| | - R. Darío Falcone
- 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
| | - N. Mariano Correa
- Departamento de Química, Universidad Nacional de Río Cuarto, Agencia Postal # 3. C.P., X5804BYA Río Cuarto, Argentina
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Phukon A, Barman N, Sahu K. Wet Interface of Benzylhexadecyldimethylammonium Chloride Reverse Micelle Revealed by Excited State Proton Transfer of a Localized Probe. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:12587-12596. [PMID: 26540303 DOI: 10.1021/acs.langmuir.5b03632] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Excited state proton transfer (ESPT) of an anionic photoacid 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS or pyranine) has been studied inside a cationic reverse micelle (RM), water/benzylhexadecyldimethylammonium chloride (BHDC)/benzene, using steady-state and time-resolved fluorescence spectroscopy. The observed ESPT behavior is found to be remarkably different from the known ESPT trend of HPTS inside anionic AOT and cationic CTAB RMs; the ESPT dynamics approaches that of bulk water at higher w0 (≥10) inside AOT RM while no ESPT was observed for CTAB reverse micelle [ Sedgwick J. Am. Chem. Soc. 2012 , 134 , 11904 - 11907 ]. The ESPT dynamics inside BHDC RM is remarkably slower compared to that of water at all w0 (= [water]/[surfactant]) values and relatively much less sensitive to w0 variation compared to AOT RM. 2D NOESY and fluorescence anisotropy measurements reveal that the probe (HPTS) is embedded inside the positive interface of BHDC RM. Despite its trapped location, HPTS is able to undergo ESPT due to significant penetration of water molecules into the interface. Furthermore, facile ESPT at higher w0 is consistent with higher degree of interface hydration as predicted by a recent MD simulation [ Agazzi Langmuir 2014 , 30 , 9643 - 9653 ]. The study shows that ESPT dynamics inside RM varies not only with the interface charge but also on the nature of the headgroup and solvation.
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Affiliation(s)
- Aparajita Phukon
- Department of Chemistry, Indian Institute of Technology Guwahati , Guwahati 781039, Assam, India
| | - Nabajeet Barman
- Department of Chemistry, Indian Institute of Technology Guwahati , Guwahati 781039, Assam, India
| | - Kalyanasis Sahu
- Department of Chemistry, Indian Institute of Technology Guwahati , Guwahati 781039, Assam, India
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Florez Tabares JS, Correa NM, Silber JJ, Sereno LE, Molina PG. Droplet-droplet interactions investigated using a combination of electrochemical and dynamic light scattering techniques. The case of water/BHDC/benzene:n-heptane system. SOFT MATTER 2015; 11:2952-2962. [PMID: 25727358 DOI: 10.1039/c5sm00146c] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In this contribution the electrochemistry of [Fe(CN)6](4-/3-) as the probe molecule was investigated in benzyl-n-hexadecyldimethylammonium chloride (BHDC) reverse micelles (RMs) varying the composition of the external solvent (benzene:n-heptane mixtures) and the surfactant concentration, at a fixed water content and probe concentration. The electrochemical and dynamic light scattering results show that in water/BHDC/benzene:n-heptane systems the aggregate sizes increase on increasing BHDC concentration. This behavior was unexpected since it is known that for water/BHDC/benzene RM systems keeping the water content constant and the surfactant concentration below 0.2 M, the droplet sizes are independent of the concentration of the surfactant. We explain the results considering that on changing the external solvent to benzene:n-heptane mixtures, RMs tend to associate in clusters and equilibrium between free RMs and droplet clusters is established. A model is presented which, using electrochemical and dynamic light scattering data, allows calculating the aggregation number of the RMs, the number of RMs that form the droplet clusters and the standard electron transfer heterogeneous rate constant.
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20
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Fan D, Zheng P, Ma Y, Yin T, Zhao J, Shen W. Effects of water content and chain length of n-alkane on the interaction enthalpy between the droplets in water/sodium bis(2-ethylhexyl)-sulfosuccinate/n-alkane microemulsions. SOFT MATTER 2015; 11:2885-2892. [PMID: 25727484 DOI: 10.1039/c5sm00319a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The concentration-dependent enthalpies of mixing for water/sodium bis(2-ethylhexyl)-sulfosuccinate (AOT)/n-alkane microemulsions with different water contents ω0 and chain lengths n of n-alkane were determined by isothermal titration microcalorimetry (ITC) and flow-mixing microcalorimetry at 298.15 K and used to calculate the interaction enthalpies (-ΔH(C)) between the droplets. It was found that -ΔH(C) increased with ω0, and changed from negative to positive at about ω0 = 10. The investigation of the dependence of -ΔH(C) on n revealed that the values of -ΔH(C) were negative and had a minimum for ω0 = 5; while they were positive and had a maximum for ω0 = 15. These phenomena were discussed based on the competition of the overlapping contribution of the surfactant tails between two neighbouring droplets and the penetration contribution of the solvent molecules into the surfactant tails. These results indicated the important role of entropy in the stability of the microemulsion systems.
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Affiliation(s)
- Dashuang Fan
- Department of Chemistry, Lanzhou University, Lanzhou, Gansu 730000, China.
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Gutierrez JA, Alejandra Luna M, Mariano Correa N, Silber JJ, Darío Falcone R. The impact of the polar core size and external organic media composition on micelle–micelle interactions: the effect on gold nanoparticle synthesis. NEW J CHEM 2015. [DOI: 10.1039/c5nj01126d] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
An easy way to modulate reverse micelles as nanoreactors to produce different kinds of gold nanoparticles.
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Affiliation(s)
- Jorge A. Gutierrez
- Departamento de Química
- Universidad Nacional de Río Cuarto
- Río Cuarto
- Argentina
| | - M. Alejandra Luna
- Departamento de Química
- Universidad Nacional de Río Cuarto
- Río Cuarto
- Argentina
| | - N. Mariano Correa
- Departamento de Química
- Universidad Nacional de Río Cuarto
- Río Cuarto
- Argentina
| | - Juana J. Silber
- Departamento de Química
- Universidad Nacional de Río Cuarto
- Río Cuarto
- Argentina
| | - R. Darío Falcone
- Departamento de Química
- Universidad Nacional de Río Cuarto
- Río Cuarto
- Argentina
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22
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Villa CC, Correa NM, Silber JJ, Moyano F, Falcone RD. Singularities in the physicochemical properties of spontaneous AOT-BHD unilamellar vesicles in comparison with DOPC vesicles. Phys Chem Chem Phys 2015; 17:17112-21. [DOI: 10.1039/c5cp02387d] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
AOT-BHD vesicles present a bilayer completely different to the traditional DOPC vesicles, with low polarity, high viscosity and more electron donor capacity.
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Affiliation(s)
- Cristian C. Villa
- Departamento de Química
- Universidad Nacional de Río Cuarto
- C.P. X5804BYA Río Cuarto
- Argentina
| | - N. Mariano Correa
- Departamento de Química
- Universidad Nacional de Río Cuarto
- C.P. X5804BYA Río Cuarto
- Argentina
| | - Juana J. Silber
- Departamento de Química
- Universidad Nacional de Río Cuarto
- C.P. X5804BYA Río Cuarto
- Argentina
| | - Fernando Moyano
- Departamento de Química
- Universidad Nacional de Río Cuarto
- C.P. X5804BYA Río Cuarto
- Argentina
| | - R. Darío Falcone
- Departamento de Química
- Universidad Nacional de Río Cuarto
- C.P. X5804BYA Río Cuarto
- Argentina
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23
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Girardi VR, Silber JJ, Mariano Correa N, Darío Falcone R. The use of two non-toxic lipophilic oils to generate environmentally friendly anionic reverse micelles without cosurfactant. Comparison with the behavior found for traditional organic non-polar solvents. Colloids Surf A Physicochem Eng Asp 2014. [DOI: 10.1016/j.colsurfa.2014.05.077] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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24
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Agazzi FM, Correa NM, Rodriguez J. Molecular dynamics simulation of water/BHDC cationic reverse micelles. structural characterization, dynamical properties, and influence of solvent on intermicellar interactions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:9643-9653. [PMID: 25068175 DOI: 10.1021/la501964q] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We report results obtained from molecular dynamics (MD) experiments of benzylhexadecyldimethylammonium chloride (BHDC) cationic reverse micelles (RMs). In particular we analyzed equilibrium and dynamical characteristics of water/BHDC RMs in pure benzene, at two different water/BHDC ratios (W0 = 5 and W0 = 10). The RMs appear as elliptical aggregates with eccentricities close to ∼0.9. Analysis of the different spatial correlations reveals three different spatial domains in the RMs: a water inner pool, the surfactant interface, and the external solvent. The calculated accessible surface areas for the aqueous inner cores suggest a strong penetration of solvent molecules within the micellar interface domains. Comparison between the density profiles of both RMs shows an increment of the broadness in the distributions of all species at the interface, along with an increasing overlap between the tail segments of the surfactant and benzene molecules as one considers larger micelles. For the dynamical side, the rotational characteristic time scale for the confined water was found to be 1 order of magnitude larger than that of the bulk water. A similar effect was also observed for hydrogen bond dynamics. Both retardation effects diminish with the size of the aggregate. To the estimate the influence of the external solvent on the intermicellar interactions, free energy profiles for the coalescence process between RMs of similar size in pure benzene and in a n-heptane/benzene mixture were also investigated. The results indicate that the association process is facilitated by the presence of n-heptane in the external nonpolar phase. Comparison with previous theoretical and experimental results is also carried out.
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Affiliation(s)
- Federico M Agazzi
- Departamento de Quı́mica, Universidad Nacional de Rı́o Cuarto , Agencia Postal 3, C.P. X5804BYA Rı́o Cuarto, Argentina
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25
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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.
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Affiliation(s)
- Cristian C Villa
- Departamento de Química, Universidad Nacional de Río Cuarto, Agencia Postal # 3. C.P. X5804BYA Río Cuarto (Argentina)
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26
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Gutierrez JA, Falcone RD, Lopez-Quintela MA, Buceta D, Silber JJ, Correa NM. On the Investigation of the Droplet-Droplet Interactions of Sodium 1,4-Bis(2-ethylhexyl) Sulfosuccinate Reverse Micelles upon Changing the External Solvent Composition and Their Impact on Gold Nanoparticle Synthesis. Eur J Inorg Chem 2014. [DOI: 10.1002/ejic.201301612] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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27
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Thakur R, Das A, Chakraborty A. Interaction of human serum albumin with liposomes of saturated and unsaturated lipids with different phase transition temperatures: a spectroscopic investigation by membrane probe PRODAN. RSC Adv 2014. [DOI: 10.1039/c4ra01214c] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The interaction of human serum albumin (HSA) with liposomes made of saturated and unsaturated phosphocholines has been studied using circular dichroism (CD), steady state and time resolved fluorescence spectroscopic techniques.
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Affiliation(s)
- Raina Thakur
- Department of Chemistry
- Indian Institute of Technology Indore
- , India
| | - Anupam Das
- Department of Chemistry
- Indian Institute of Technology Indore
- , India
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28
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Odella E, Falcone RD, Silber JJ, Correa NM. How TOPO affects the interface of the novel mixed water/AOT:TOPO/n-heptane reverse micelles: dynamic light scattering and Fourier transform infrared spectroscopy studies. Phys Chem Chem Phys 2014; 16:15457-68. [DOI: 10.1039/c4cp01026d] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The proportion of TOPO in water/AOT:TOPO/n-heptane reverse micelles produces dramatic changes in the water structure, droplet size and composition of the interface.
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Affiliation(s)
- Emmanuel Odella
- Departamento de Química
- Universidad Nacional de Río Cuarto
- C.P. X5804BYA Río Cuarto, Argentina
| | - R. Darío Falcone
- Departamento de Química
- Universidad Nacional de Río Cuarto
- C.P. X5804BYA Río Cuarto, Argentina
| | - Juana J. Silber
- Departamento de Química
- Universidad Nacional de Río Cuarto
- C.P. X5804BYA Río Cuarto, Argentina
| | - N. Mariano Correa
- Departamento de Química
- Universidad Nacional de Río Cuarto
- C.P. X5804BYA Río Cuarto, Argentina
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