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Delance L, Santanach-Carreras E, Passade-Boupat N, Lequeux F, Talini L, Verneuil E. How emulsified droplets induce the bursting of suspended films of liquid mixtures. SOFT MATTER 2024; 20:5407-5416. [PMID: 38941082 DOI: 10.1039/d4sm00240g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/29/2024]
Abstract
Emulsion droplets of silicone oil (PDMS) are widely used as antifoaming agents but, in the case of non-aqueous foams, the mechanisms responsible for the bursting of the films separating the bubbles remain unclear. We consider a ternary non-aqueous liquid mixture in which PDMS-rich microdroplets are formed by spontaneous emulsification. In order to quantitatively assess the effect of the emulsified microdroplets, we measure the lifetime of sub-micrometer-thick suspended films of these emulsions as well as the time variations of their thickness profiles. We observe that a droplet entering the film reduces its lifetime by inducing a local and fast thinning. In most cases, we ascribe it to the spreading of the drop at one of the film interfaces with air, which drags the underlying liquid and eventually causes the film to burst rapidly. We explain why, despite slower spreading, more viscous droplets cause films to burst more efficiently. More rarely, microdroplets may bridge the two interfaces of the film, resulting in an even more efficient bursting of the film, which we explain.
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Affiliation(s)
- Léa Delance
- Soft Matter Sciences and Engineering (SIMM), ESPCI Paris, PSL University, Sorbonne Université, CNRS, F-75005 Paris, France.
- Laboratoire Physico-Chimie des Interfaces Complexes, ESPCI Paris, 10 rue Vauquelin, F-75231 Paris, France
- TOTALEnergies S.A., Pôle d'Etudes et de Recherches de Lacq, BP 47, 64170 Lacq, France
| | - Enric Santanach-Carreras
- TOTALEnergies S.A., Pôle d'Etudes et de Recherches de Lacq, BP 47, 64170 Lacq, France
- Laboratoire Physico-Chimie des Interfaces Complexes, Chemstartup, RD 817, 64170 Lacq, France
| | - Nicolas Passade-Boupat
- TOTALEnergies S.A., Pôle d'Etudes et de Recherches de Lacq, BP 47, 64170 Lacq, France
- Laboratoire Physico-Chimie des Interfaces Complexes, Chemstartup, RD 817, 64170 Lacq, France
| | - François Lequeux
- Soft Matter Sciences and Engineering (SIMM), ESPCI Paris, PSL University, Sorbonne Université, CNRS, F-75005 Paris, France.
- Laboratoire Physico-Chimie des Interfaces Complexes, ESPCI Paris, 10 rue Vauquelin, F-75231 Paris, France
| | - Laurence Talini
- CNRS, Surface du Verre et Interfaces, Saint-Gobain, 93300 Aubervilliers, France.
| | - Emilie Verneuil
- Soft Matter Sciences and Engineering (SIMM), ESPCI Paris, PSL University, Sorbonne Université, CNRS, F-75005 Paris, France.
- Laboratoire Physico-Chimie des Interfaces Complexes, ESPCI Paris, 10 rue Vauquelin, F-75231 Paris, France
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Lombardi L, Roig-Sanchez S, Bapat A, Frostad JM. Nonaqueous foam stabilization mechanisms in the presence of volatile solvents. J Colloid Interface Sci 2023; 648:46-55. [PMID: 37295369 DOI: 10.1016/j.jcis.2023.05.156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 05/17/2023] [Accepted: 05/24/2023] [Indexed: 06/12/2023]
Abstract
Hypothesis Nonaqueous foams are found in a variety of applications, many of which contain volatile components that need to be removed during processing. Sparging air bubbles into the liquid can be used to aid in their removal, but the resulting foam can be stabilized or destabilized by several different mechanisms, the relative importance of which are not yet fully understood. Investigating the dynamics of thin film drainage, four competing mechanisms can be observed, such as solvent evaporation, film viscosification, and thermal and solutocapillary Marangoni flows. Experiments Experimental studies with isolated bubbles and/or bulk foams are needed to strengthen the fundamental knowledge of these systems. This paper presents interferometric measurements of the dynamic evolution of a film formed by a bubble rising to an air-liquid interface to shed light on this situation. Two different solvents with different degrees of volatility were investigated to reveal both qualitative and quantitative details on thin film drainage mechanisms in polymer-volatile mixtures. Findings Using interferometry, we found evidence that solvent evaporation and film viscosification both strongly influence the stability of interface. These findings were corroborated by comparison with bulk foam measurements, revealing a strong correlation between these two systems.
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Affiliation(s)
- Lorenzo Lombardi
- Department of Chemical, Materials and Production Engineering, University of Naples Federico II, P.le Tecchio 80, Naples, 80125, Italy.
| | - Soledad Roig-Sanchez
- Chemical and Biological Engineering, University of British Columbia, 2360 E Mall, Vancouver, V6T 1Z3, BC, Canada; Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, V6T 1Z1, BC, Canada
| | - Amar Bapat
- Department of Mechanical Engineering, Indian Institute of Technology, Kharagpur, 721302, West Bengal, India
| | - John M Frostad
- Chemical and Biological Engineering, University of British Columbia, 2360 E Mall, Vancouver, V6T 1Z3, BC, Canada; Food Science, University of British Columbia, 2205 E Mall, Vancouver, V6T 1Z4, BC, Canada
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Arnaudova T, Mitrinova Z, Denkov N, Growney D, Brenda R, Tcholakova S. Foamability and foam stability of oily mixtures. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.129987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Tran HP, Delance L, Passade-Boupat N, Verneuil E, Lequeux F, Talini L. Foaming of Binary Mixtures: Link with the Nonlinear Behavior of Surface Tension in Asymmetric Mixtures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:13444-13451. [PMID: 34726919 DOI: 10.1021/acs.langmuir.1c02198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The lifetimes of single bubbles or foams that are formed in mixtures of liquids can be several orders of magnitude larger than the ones formed in pure liquids. We recently demonstrated that this enhanced stability results from differences between bulk and interfacial concentrations in the mixture, which induce a thickness dependence of the surface tension in liquid films, and thus a stabilizing Marangoni effect. Concentration differences may be associated with nonlinear variations of surface tension with composition and we further investigate their link with foamability of binary mixtures. We show that, for asymmetric binary mixtures, that is, made of molecules of very different sizes, strong nonlinearities in surface tension can be measured, that are associated with large foam lifetimes. When the molecules that occupy the largest surface areas have the smallest surface tension, the surface tension of the mixture varies sublinearly with composition, reflecting an enrichment in this species at the interface with air, as classically reported in the literature. In contrast, when they exhibit the largest surface tension, superlinear variations of surface tension are observed, despite a similar enrichment. We discuss these variations in light of a simple thermodynamic model for ideal mixtures and we demonstrate why foam stability is enhanced for both sublinear and superlinear surface tension variations, thus, shedding new light on foamability without added surfactants.
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Affiliation(s)
- H P Tran
- CNRS, Sciences et Ingénierie de la Matière Molle, ESPCI Paris, PSL Research University, Sorbonne Université, 75005 Paris, France
- Laboratoire Physico-Chimie des Interfaces Complexes, ESPCI, 10 rue Vauquelin, 75005 Paris, France
- Bâtiment CHEMSTARTUP, Route Départementale 817, 64170 Lacq, France
| | - L Delance
- CNRS, Sciences et Ingénierie de la Matière Molle, ESPCI Paris, PSL Research University, Sorbonne Université, 75005 Paris, France
- Laboratoire Physico-Chimie des Interfaces Complexes, ESPCI, 10 rue Vauquelin, 75005 Paris, France
- Bâtiment CHEMSTARTUP, Route Départementale 817, 64170 Lacq, France
| | - N Passade-Boupat
- Laboratoire Physico-Chimie des Interfaces Complexes, ESPCI, 10 rue Vauquelin, 75005 Paris, France
- Bâtiment CHEMSTARTUP, Route Départementale 817, 64170 Lacq, France
- Total S.A. 64170 Lacq, France
| | - E Verneuil
- CNRS, Sciences et Ingénierie de la Matière Molle, ESPCI Paris, PSL Research University, Sorbonne Université, 75005 Paris, France
- Laboratoire Physico-Chimie des Interfaces Complexes, ESPCI, 10 rue Vauquelin, 75005 Paris, France
- Bâtiment CHEMSTARTUP, Route Départementale 817, 64170 Lacq, France
| | - F Lequeux
- CNRS, Sciences et Ingénierie de la Matière Molle, ESPCI Paris, PSL Research University, Sorbonne Université, 75005 Paris, France
- Laboratoire Physico-Chimie des Interfaces Complexes, ESPCI, 10 rue Vauquelin, 75005 Paris, France
- Bâtiment CHEMSTARTUP, Route Départementale 817, 64170 Lacq, France
| | - L Talini
- CNRS, Surface du Verre et Interfaces, Saint-Gobain, 93300 Aubervilliers, France
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