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Goubault C, Iglicki D, Swain RA, McVey BFP, Lefeuvre B, Rault L, Nayral C, Delpech F, Kahn ML, Chevance S, Gauffre F. Effect of nanoparticles on spontaneous Ouzo emulsification. J Colloid Interface Sci 2021; 603:572-581. [PMID: 34216953 DOI: 10.1016/j.jcis.2021.06.104] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 06/17/2021] [Accepted: 06/18/2021] [Indexed: 10/21/2022]
Abstract
Particles stabilize fluid interfaces. In particular, oil/water Pickering emulsions undergo limited coalescence, yielding droplets of smaller size as the amount of particles is increased. Herein, we studied the effect of hydrophobic nanoparticles (<10 nm, alkyl-coated) on submicronic droplets (ca 100 nm) formed in an Ouzo system. We investigated thoroughly the water/tetrahydrofuran (THF)/butylated hydroxytoluene (BHT) reference diagram, in the absence and in the presence of nanoparticles, using the Nanoparticle Tracking Analysis (NTA) technique. This allowed us to characterize the size distributions in a much finer way than what is usually obtained using conventional Dynamic Light Scattering (DLS). Both a Surfactant-Free Microemulsion (SFME, thermodynamically stable) and an Ouzo (metastable spontaneous emulsion) domains were identified and the transition from one to the other could be characterized by specific features of the droplet size distributions. We found that the presence of the nanoparticles limits coalescence in the metastable domain. We also show that the alkyl-coated nanoparticles are irreversibly attached to the liquid-liquid interface.
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Affiliation(s)
| | | | - Robert A Swain
- LPCNO, Université de Toulouse, CNRS, INSA, UPS, 135 Avenue de Rangueil, F-31077 Toulouse, France
| | - Benjamin F P McVey
- LPCNO, Université de Toulouse, CNRS, INSA, UPS, 135 Avenue de Rangueil, F-31077 Toulouse, France
| | | | - Ludivine Rault
- Univ Rennes, CNRS, ScanMAT - UMS 2001, F-35000 Rennes, France
| | - Céline Nayral
- LPCNO, Université de Toulouse, CNRS, INSA, UPS, 135 Avenue de Rangueil, F-31077 Toulouse, France
| | - Fabien Delpech
- LPCNO, Université de Toulouse, CNRS, INSA, UPS, 135 Avenue de Rangueil, F-31077 Toulouse, France
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Koroleva MY, Yurtov EV. Ostwald ripening in macro- and nanoemulsions. RUSSIAN CHEMICAL REVIEWS 2021. [DOI: 10.1070/rcr4962] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Zadymova NM, Yampol’skaya GP, Poteshnova MV, Kulichikhin VG. Emulsion approach to production of polymer films used as carriers of lysozyme. COLLOID JOURNAL 2011. [DOI: 10.1134/s1061933x11050218] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Urbina-Villalba G, García-Sucre M. Role of the secondary minimum on the flocculation rate of nondeformable droplets. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:6675-87. [PMID: 16008374 DOI: 10.1021/la050024p] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The kinetic stability of suspensions is usually associated with a decrease in the flux of flocculating particles due to the action of a repulsive potential. However, previous calculations on bitumen drops suggest the possible occurrence of relatively fast aggregation rates in systems with large electrostatic barriers for primary minimum flocculation. This indicates a strong effect of the secondary minimum in the process of aggregation. Here, emulsion stability simulations (ESS) are used to study the aggregation behavior of 11 systems showing different depths of the secondary minimum and three particle sizes. Micron size drops (as those of Bitumen emulsions) usually exhibit deep secondary minima, which rarely occur between nanometer size particles. At high surfactant concentrations, these drops do not coalesce but can still show fast aggregation rates caused by irreversible secondary-minimum flocculation. On the other hand, the extent of coalescence in nanometer-size systems markedly depends on the height of the repulsive barrier. Furthermore, the secondary minimum of these smaller particles is usually shallow, causing reversible aggregation or no aggregation at all. In this article, the consequences of the referred behaviors on the magnitude of the stability ratio are discussed.
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Affiliation(s)
- German Urbina-Villalba
- Instituto Venezolano de Investigaciones Científicas (IVIC), Centro de Física, Laboratorio de Fisicoquímica de Coloides, Aptdo. 21827, Caracas 1020-A, Venezuela.
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