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Influence of structurally related micelle forming surfactants on the antioxidant activity of natural substances. Chem Phys Lipids 2019; 225:104818. [DOI: 10.1016/j.chemphyslip.2019.104818] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 08/22/2019] [Accepted: 09/04/2019] [Indexed: 11/23/2022]
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Tojo C, de Dios M, Buceta D, López-Quintela MA. Cage-like effect in Au-Pt nanoparticle synthesis in microemulsions: a simulation study. Phys Chem Chem Phys 2015; 16:19720-31. [PMID: 25115366 DOI: 10.1039/c4cp02936d] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The different distributions of metals in bimetallic nanoparticles synthesized in microemulsions were studied by computer simulation. The simulations demonstrated that if the difference between the reduction potentials of both metals is about 0.15-0.3 V, the compartmentalization of the reaction media causes the accumulation of slower reduction reactants in the microemulsions droplets, which favours the chemical reaction like a cage effect: increasing the local concentration of the slower reduction metal salt gives rise to a faster reduction, so the differences in reduction rates of both metals are attenuated. A more coincidental reduction of both metals deeply affects the nanoparticle structure, causing a better mixed alloy. This effect will be more pronounced when the concentration is higher and the intermicellar exchange rate is faster. This means that for any fixed microemulsion the nanoparticle structure can be modified by changing the reactant concentration: the core can be enriched in the faster reduction metal by lower concentrations, and the shell can be enriched in the slower metal by higher concentrations. Based on these observations, this study suggests a route to help experimentalists better create nanoparticles with a pre-defined structure.
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Affiliation(s)
- C Tojo
- Physical Chemistry Department, Faculty of Chemistry, University of Vigo, E-36310 Vigo, Spain.
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Wang C, Lin C, Zhang L, Quan Z, Sun K, Zhao B, Wang F, Porter N, Wang Y, Fang J. Pt3Co Concave Nanocubes: Synthesis, Formation Understanding, and Enhanced Catalytic Activity toward Hydrogenation of Styrene. Chemistry 2013; 20:1753-9. [DOI: 10.1002/chem.201301724] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 11/26/2013] [Indexed: 11/12/2022]
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Volovych I, Schwarze M, Hamerla T, Blum J, Schomäcker R. Enantioselective hydrogenation of itaconic acid and its derivates with sol–gel immobilized Rh/BPPM catalysts. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.molcata.2012.10.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Schwarze M, Schmidt M, Nguyen L, Drews A, Kraume M, Schomäcker R. Micellar enhanced ultrafiltration of a rhodium catalyst. J Memb Sci 2012. [DOI: 10.1016/j.memsci.2012.07.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Niedziółka K, Szymula M, Lewińska A, Wilk K, Narkiewicz-Michałek J. Studies of vitamin C antioxidative activity in the N-oxide surfactant solutions. Colloids Surf A Physicochem Eng Asp 2012. [DOI: 10.1016/j.colsurfa.2012.02.047] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Tang JA, Gruppi F, Fleysher R, Sodickson DK, Canary JW, Jerschow A. Extended para-hydrogenation monitored by NMR spectroscopy. Chem Commun (Camb) 2011; 47:958-60. [DOI: 10.1039/c0cc03421e] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Schwarze M, Milano-Brusco J, Strempel V, Hamerla T, Wille S, Fischer C, Baumann W, Arlt W, Schomäcker R. Rhodium catalyzed hydrogenation reactions in aqueous micellar systems as green solvents. RSC Adv 2011. [DOI: 10.1039/c1ra00397f] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Milano-Brusco JS, Schwarze M, Djennad M, Nowothnick H, Schomäcker R. Catalytic Hydrogenation of Dimethyl Itaconate in a Water−Cyclohexane−Triton X-100 Microemulsion in Comparison to a Biphasic System. Ind Eng Chem Res 2008. [DOI: 10.1021/ie800190g] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Juan S. Milano-Brusco
- Department of Chemistry, TU Berlin, Secr. TC-8, Strasse des 17. Juni 124, 10623 Berlin, Germany, and Département de Chimie, Université de Mostaganem, B. P. 188, Mostaganem, DZ 27000 Algeria
| | - Michael Schwarze
- Department of Chemistry, TU Berlin, Secr. TC-8, Strasse des 17. Juni 124, 10623 Berlin, Germany, and Département de Chimie, Université de Mostaganem, B. P. 188, Mostaganem, DZ 27000 Algeria
| | - M’hamed Djennad
- Department of Chemistry, TU Berlin, Secr. TC-8, Strasse des 17. Juni 124, 10623 Berlin, Germany, and Département de Chimie, Université de Mostaganem, B. P. 188, Mostaganem, DZ 27000 Algeria
| | - Henriette Nowothnick
- Department of Chemistry, TU Berlin, Secr. TC-8, Strasse des 17. Juni 124, 10623 Berlin, Germany, and Département de Chimie, Université de Mostaganem, B. P. 188, Mostaganem, DZ 27000 Algeria
| | - Reinhard Schomäcker
- Department of Chemistry, TU Berlin, Secr. TC-8, Strasse des 17. Juni 124, 10623 Berlin, Germany, and Département de Chimie, Université de Mostaganem, B. P. 188, Mostaganem, DZ 27000 Algeria
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Affiliation(s)
- Carmen Najera
- Departamento de Química OrgAnica, Facultad de Ciencias, and Instituto de Síntesis OrgAnica, Universidad de Alicante, Apdo. 99, 03080-Alicante, Spain.
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Schwarze M, Schomäcker R. Homogen katalysierte stereoselektive Hydrierreaktion im mizellaren Medium. CHEM-ING-TECH 2006. [DOI: 10.1002/cite.200600038] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Abstract
The notion of "green chemistry" has encouraged even synthetic organic chemists to include water as a solvent. Incredible selectivities and activities can be achieved through the addition of amphiphiles with a defined structure. The morphology of supramolecular assemblies or associates formed by surfactants vary according to the temperature and concentration. As a rule, reactions are typically conducted using simple spherical aggregates, that is, micelles in the nanometer range. The strong polarity gradient present between the hydrophilic surface and the hydrophobic core of the micelle means that both nonpolar and polar reagents can be solubilized. This solubilization results in reactants becoming more concentrated within the micelle than in the surrounding water phase and leads to an acceleration of the reaction and causes selective effects. The kinetic treatment of reactions in micellar systems can be accomplished by considering them as microheterogeneous two-phase systems.
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Affiliation(s)
- Torsten Dwars
- Leibniz-Institut für Organische Katalyse (IFOK), Universität Rostock e.V. Albert-Einstein-Strasse 29a, 18059 Rostock, Germany
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