51
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Zou Y, Wan Z, Guo J, Wang J, Yin S, Yang X. Tunable assembly of hydrophobic protein nanoparticle at fluid interfaces with tannic acid. Food Hydrocoll 2017. [DOI: 10.1016/j.foodhyd.2016.09.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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52
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Huang YR, Lamson M, Matyjaszewski K, Tilton RD. Enhanced interfacial activity of multi-arm poly(ethylene oxide) star polymers relative to linear poly(ethylene oxide) at fluid interfaces. Phys Chem Chem Phys 2017; 19:23854-23868. [DOI: 10.1039/c7cp02841e] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Interfacial tension reduction, dynamic dilatational elasticity and extent of adsorption were investigated for linear poly(ethylene oxide) (PEO) chains of varying molecular weight and for PEO star polymers with an average of 64 arms per star at air/water, xylene/water, and cyclohexane/water interfaces.
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Affiliation(s)
- Yun-Ru Huang
- Center for Complex Fluids Engineering
- Department of Chemical Engineering
- Carnegie Mellon University
- Pittsburgh
- USA
| | - Melissa Lamson
- Center for Complex Fluids Engineering
- Department of Chemistry
- Carnegie Mellon University
- Pittsburgh
- USA
| | - Krzysztof Matyjaszewski
- Center for Complex Fluids Engineering
- Department of Chemistry
- Carnegie Mellon University
- Pittsburgh
- USA
| | - Robert D. Tilton
- Center for Complex Fluids Engineering
- Department of Chemical Engineering
- Carnegie Mellon University
- Pittsburgh
- USA
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53
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Mei Y, Li G, Moldenaers P, Cardinaels R. Dynamics of particle-covered droplets in shear flow: unusual breakup and deformation hysteresis. SOFT MATTER 2016; 12:9407-9412. [PMID: 27853801 DOI: 10.1039/c6sm02031c] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The dynamics of droplets exhibiting an elastic interface generated by a percolated network of particle aggregates at the interface is microscopically investigated in a counter rotating shear flow device. The droplet deformation is significantly suppressed by interfacially localized nanoparticles, even at high Ca numbers, resulting in suspension-like behavior at high particle coverage. When the Ca number surpasses a critical value, the particle network locally breaks up, resulting in localized deformability of the interface and breakup dynamics characterized by extremely irregular shapes. Finally, the destruction of the interfacial network results in hysteresis effects in the droplet deformation.
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Affiliation(s)
- Yuan Mei
- Soft Matter Rheology and Technology, Department of Chemical Engineering, KU Leuven, Celestijnenlaan 200F, P. B. 2424, B-3001 Leuven, Belgium. and College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering of China, Sichuan University, Chengdu 610065, China
| | - Guangxian Li
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering of China, Sichuan University, Chengdu 610065, China
| | - Paula Moldenaers
- Soft Matter Rheology and Technology, Department of Chemical Engineering, KU Leuven, Celestijnenlaan 200F, P. B. 2424, B-3001 Leuven, Belgium.
| | - Ruth Cardinaels
- Soft Matter Rheology and Technology, Department of Chemical Engineering, KU Leuven, Celestijnenlaan 200F, P. B. 2424, B-3001 Leuven, Belgium. and Polymer Technology, Department of Mechanical Engineering, TU Eindhoven, P. B. 513, 5600 MB Eindhoven, The Netherlands
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54
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Rymaruk MJ, Thompson KL, Derry MJ, Warren NJ, Ratcliffe LPD, Williams CN, Brown SL, Armes SP. Bespoke contrast-matched diblock copolymer nanoparticles enable the rational design of highly transparent Pickering double emulsions. NANOSCALE 2016; 8:14497-506. [PMID: 27406976 PMCID: PMC5047046 DOI: 10.1039/c6nr03856e] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 07/04/2016] [Indexed: 05/28/2023]
Abstract
We report the preparation of highly transparent oil-in-water Pickering emulsions using contrast-matched organic nanoparticles. This is achieved via addition of judicious amounts of either sucrose or glycerol to an aqueous dispersion of poly(glycerol monomethacrylate)56-poly(2,2,2-trifluoroethyl methacrylate)500 [PGMA-PTFEMA] diblock copolymer nanoparticles prior to high shear homogenization with an equal volume of n-dodecane. The resulting Pickering emulsions comprise polydisperse n-dodecane droplets of 20-100 μm diameter and exhibit up to 96% transmittance across the visible spectrum. In contrast, control experiments using non-contrast-matched poly(glycerol monomethacrylate)56-poly(benzyl methacrylate)300 [PGMA56-PBzMA300] diblock copolymer nanoparticles as a Pickering emulsifier only produced conventional highly turbid emulsions. Thus contrast-matching of the two immiscible phases is a necessary but not sufficient condition for the preparation of highly transparent Pickering emulsions: it is essential to use isorefractive nanoparticles in order to minimize light scattering. Furthermore, highly transparent oil-in-water-in-oil Pickering double emulsions can be obtained by homogenizing the contrast-matched oil-in-water Pickering emulsion prepared using the PGMA56-PTFEMA500 nanoparticles with a contrast-matched dispersion of hydrophobic poly(lauryl methacrylate)39-poly(2,2,2-trifluoroethyl methacrylate)800 [PLMA39-PTFEMA800] diblock copolymer nanoparticles in n-dodecane. Finally, we show that an isorefractive oil-in-water Pickering emulsion enables fluorescence spectroscopy to be used to monitor the transport of water-insoluble small molecules (pyrene and benzophenone) between n-dodecane droplets. Such transport is significantly less efficient than that observed for the equivalent isorefractive surfactant-stabilized emulsion. Conventional turbid emulsions do not enable such a comparison to be made because the intense light scattering leads to substantial spectral attenuation.
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Affiliation(s)
- Matthew J. Rymaruk
- Dainton Building , Department of Chemistry , The University of Sheffield , Brook Hill , Sheffield , S3 7HF , Yorkshire , UK . ;
| | - Kate L. Thompson
- Dainton Building , Department of Chemistry , The University of Sheffield , Brook Hill , Sheffield , S3 7HF , Yorkshire , UK . ;
| | - Matthew J. Derry
- Dainton Building , Department of Chemistry , The University of Sheffield , Brook Hill , Sheffield , S3 7HF , Yorkshire , UK . ;
| | - Nicholas J. Warren
- Dainton Building , Department of Chemistry , The University of Sheffield , Brook Hill , Sheffield , S3 7HF , Yorkshire , UK . ;
| | - Liam P. D. Ratcliffe
- Dainton Building , Department of Chemistry , The University of Sheffield , Brook Hill , Sheffield , S3 7HF , Yorkshire , UK . ;
| | - Clive N. Williams
- Scott Bader Company Ltd , Wollaston, Wellingborough , NN29 7RL , Northants , UK
| | - Steven L. Brown
- Scott Bader Company Ltd , Wollaston, Wellingborough , NN29 7RL , Northants , UK
| | - Steven P. Armes
- Dainton Building , Department of Chemistry , The University of Sheffield , Brook Hill , Sheffield , S3 7HF , Yorkshire , UK . ;
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55
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Sperling M, Papadopoulos P, Gradzielski M. Understanding the Formation of Anisometric Supraparticles: A Mechanistic Look Inside Droplets Drying on a Superhydrophobic Surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:6902-8. [PMID: 27336463 DOI: 10.1021/acs.langmuir.6b01236] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Evaporating drops of nanoparticle suspensions on superhydrophobic surfaces can give anisotropic superaparticles. Previous studies implied the formation of a stiff shell that collapses, but the exact mechanism leading to anisotropy was unclear so far. Here we report on a new experiment using confocal laser scanning microscopy for a detailed characterization of particle formation from droplets of aqueous colloidal dispersions on superhydrophobic surfaces. In a customized setup, we investigated droplets of fumed silica suspensions using two different fluorescent dyes for independently marking silica and the water phase. Taking advantage of interfacial reflection, we locate the drop-air interface and extract normalized time-resolved intensity profiles for dyed silica throughout the drying process. Using comprehensive image analysis we observe and quantify shell-like interfacial particle accumulation arising from droplet evaporation. This leads to a buildup of a stiff fumed silica mantle of ∼20 μm thickness that causes deformation of the droplet throughout further shrinkage, consequently leading to the formation of solid anisometric fumed silica particles.
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Affiliation(s)
- Marcel Sperling
- Technische Universität Berlin (TU Berlin) , Institut für Chemie - Stranski Laboratorium für Physikalische und Theoretische Chemie, Straße des 17. Juni 124, D-10623 Berlin, Germany
| | - Periklis Papadopoulos
- University of Ioannina , Department of Physics, P.O. Box 1186, GR-45110 Ioannina, Greece
| | - Michael Gradzielski
- Technische Universität Berlin (TU Berlin) , Institut für Chemie - Stranski Laboratorium für Physikalische und Theoretische Chemie, Straße des 17. Juni 124, D-10623 Berlin, Germany
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56
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Jiang L, Li S, Yu W, Wang J, Sun Q, Li Z. Interfacial study on the interaction between hydrophobic nanoparticles and ionic surfactants. Colloids Surf A Physicochem Eng Asp 2016. [DOI: 10.1016/j.colsurfa.2015.10.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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57
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Dilational surface elasticity of monolayers of charged polystyrene nano- and microparticles at liquid/fluid interfaces. Colloids Surf A Physicochem Eng Asp 2015. [DOI: 10.1016/j.colsurfa.2015.09.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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58
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Bournival G, Ata S, Wanless EJ. The roles of particles in multiphase processes: Particles on bubble surfaces. Adv Colloid Interface Sci 2015; 225:114-33. [PMID: 26344866 DOI: 10.1016/j.cis.2015.08.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 08/16/2015] [Accepted: 08/16/2015] [Indexed: 10/23/2022]
Abstract
Particle-stabilised foams (or froths) form the fundamental framework of industrial processes like froth flotation. This review provides an overview of the effects of particles on bubble surfaces. The characteristics of the particles have a profound effect on the stability of the bubbles although the stabilisation mechanisms may differ. It is well known that layers of particles may provide a steric barrier between two interfaces, which prevents the coalescence of bubbles. Although perhaps considered of lesser importance, it is interesting to note that particles may affect the bubble surface and momentarily suppress coalescence despite being absent from the film separating two bubbles. Foams are at best metastable and coalescence occurs to achieve a state of minimum energy. Despite this, particles have been reported to stabilise bubbles for significant periods of time. Bubble coalescence is accompanied by a release of energy triggered by the sudden change in surface area. This produces a distinctive oscillation of the bubble surface, which may be influenced by the presence of incompressible particles yielding unique surface properties. A survey of the literature shows that the properties of these composite materials are greatly affected by the physicochemical characteristics of the particles such as hydrophobicity and size. The intense energy released during the coalescence of bubbles may be sufficient to expel particles from the bubble surface. It is noted that the detachment of particles may preferentially occur from specific locations on the bubble surface. Examination of the research accounts again reveals that the properties of the particles may affect their detachment upon the oscillation of the bubble surface. However, it is believed that most parameters affecting the detachment of particles are in fact modifying the dynamics of the three-phase line of contact. Both the oscillation of a coalescing bubble and the resulting detachment of particles are highly dynamic processes. They would greatly benefit from computer simulation studies.
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59
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Deshmukh OS, van den Ende D, Stuart MC, Mugele F, Duits MHG. Hard and soft colloids at fluid interfaces: Adsorption, interactions, assembly & rheology. Adv Colloid Interface Sci 2015; 222:215-27. [PMID: 25288385 DOI: 10.1016/j.cis.2014.09.003] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 09/09/2014] [Accepted: 09/13/2014] [Indexed: 11/15/2022]
Abstract
Soft microgel particles inherently possess qualities of both polymers as well as particles. We review the similarities and differences between soft microgel particles and stiff colloids at fluid-fluid interfaces. We compare two fundamental aspects of particle-laden interfaces namely the adsorption kinetics and the interactions between adsorbed particles. Although it is well established that the transport of both hard particles and microgels to the interface is driven by diffusion, the analysis of the adsorption kinetics needs reconsideration and a proper equation of state relating the surface pressure to the adsorbed mass should be used. We review the theoretical and experimental investigations into the interactions of particles at the interface. The rheology of the interfacial layers is intimately related to the interactions, and the differences between hard particles and microgels become pronounced. The assembly of particles into the layer is another distinguishing factor that separates hard particles from soft microgel particles. Microgels deform substantially upon adsorption and the stability of a microgel-stabilized emulsion depends on the conformational changes triggered by external stimuli.
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Affiliation(s)
- Omkar S Deshmukh
- Physics of Complex Fluids Group, Dept. Science and Technology, University of Twente, Enschede, The Netherlands
| | - Dirk van den Ende
- Physics of Complex Fluids Group, Dept. Science and Technology, University of Twente, Enschede, The Netherlands
| | - Martien Cohen Stuart
- Physics of Complex Fluids Group, Dept. Science and Technology, University of Twente, Enschede, The Netherlands; Laboratory of Physical Chemistry and Colloid Science, Wageningen University, Wageningen, The Netherlands
| | - Frieder Mugele
- Physics of Complex Fluids Group, Dept. Science and Technology, University of Twente, Enschede, The Netherlands
| | - Michel H G Duits
- Physics of Complex Fluids Group, Dept. Science and Technology, University of Twente, Enschede, The Netherlands.
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60
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Razavi S, Cao KD, Lin B, Lee KYC, Tu RS, Kretzschmar I. Collapse of Particle-Laden Interfaces under Compression: Buckling vs Particle Expulsion. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:7764-75. [PMID: 26099031 DOI: 10.1021/acs.langmuir.5b01652] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Colloidal particles can bind to fluid interfaces with a capillary energy that is thousands of times the thermal energy. This phenomenon offers an effective route to emulsion and foam stabilization where the stability is influenced by the phase behavior of the particle-laden interface under deformation. Despite the vast interest in particle-laden interfaces, the key factors that determine the collapse of such an interface under compression have remained relatively unexplored. In this study, we illustrate the significance of the particle surface wettability and presence of electrolyte in the subphase on interparticle interactions at the interface and the resulting collapse mode. Various collapse mechanisms including buckling, particle expulsion, and multilayer formation are reported and interpreted in terms of particle-particle and particle-interface interactions.
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Affiliation(s)
- Sepideh Razavi
- †Department of Chemical Engineering, City College of City University of New York, New York, New York 10031, United States
| | | | | | | | - Raymond S Tu
- †Department of Chemical Engineering, City College of City University of New York, New York, New York 10031, United States
| | - Ilona Kretzschmar
- †Department of Chemical Engineering, City College of City University of New York, New York, New York 10031, United States
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61
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Maestro A, Deshmukh OS, Mugele F, Langevin D. Interfacial Assembly of Surfactant-Decorated Nanoparticles: On the Rheological Description of a Colloidal 2D Glass. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:6289-6297. [PMID: 25973738 DOI: 10.1021/acs.langmuir.5b00632] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We address the rheology of assemblies of surfactant-decorated silica nanoparticles irreversibly adsorbed at the gas/liquid interface. Positively charged surfactant molecules (such as CTAB) bind to silica nanoparticle surfaces, and the resulting particle-surfactant complexes adsorb at gas/liquid interfaces. The surfactant molecules control the wettability of such decorated nanoparticles and their adsorption. The interparticle forces can be tuned by changing the surfactant concentration Cs. Increasing Cs, in addition to a decrease of the particles wettability, leads to an increase of the area fraction of particles at the interface. Oscillatory shear measurements (strain- and frequency-sweep) have been performed. Here, we explore the effect of the surfactant concentration Cs. At high enough Cs, the interface is highly packed, and an overall solidlike response is observed, with 2D glass properties.
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Affiliation(s)
- Armando Maestro
- †Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, U.K
| | - Omkar S Deshmukh
- ‡Physics of Complex Fluids, Department of Science and Technology, University of Twente, PO Box 217, Enschede, The Netherlands
| | - Frieder Mugele
- ‡Physics of Complex Fluids, Department of Science and Technology, University of Twente, PO Box 217, Enschede, The Netherlands
| | - Dominique Langevin
- §Laboratoire de Physique des Solides, CNRS UMR 8502, Bat. 510, Universite Paris-Sud XI, 91405 Orsay, France
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62
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Cilek EC, Karaca S. Effect of nanoparticles on froth stability and bubble size distribution in flotation. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.minpro.2015.03.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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63
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Kolwas M, Kolwas K, Derkachov G, Jakubczyk D. Surface diagnostics of evaporating droplets of nanosphere suspension: Fano interference and surface pressure. Phys Chem Chem Phys 2015; 17:6881-8. [DOI: 10.1039/c5cp00013k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The demonstrated temporal Fano interference of light scattered by evaporating droplets of a nano-suspension can be a powerful tool to characterize interfaces of evaporating liquids.
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Affiliation(s)
- Maciej Kolwas
- Institute of Physics
- Polish Academy of Sciences
- 02-668 Warszawa
- Poland
| | - Krystyna Kolwas
- Institute of Physics
- Polish Academy of Sciences
- 02-668 Warszawa
- Poland
| | | | - Daniel Jakubczyk
- Institute of Physics
- Polish Academy of Sciences
- 02-668 Warszawa
- Poland
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64
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Persson KH, Blute IA, Mira IC, Gustafsson J. Creation of well-defined particle stabilized oil-in-water nanoemulsions. Colloids Surf A Physicochem Eng Asp 2014. [DOI: 10.1016/j.colsurfa.2014.06.034] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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65
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Fainerman VB, Aksenenko EV, Mucic N, Javadi A, Miller R. Thermodynamics of adsorption of ionic surfactants at water/alkane interfaces. SOFT MATTER 2014; 10:6873-6887. [PMID: 24909966 DOI: 10.1039/c4sm00463a] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
On the basis of experimental data for the homologous series of alkyltrimethylammonium bromides (CnTAB) the equilibrium surface tension isotherms at three types of liquid-fluid interfaces are discussed: solution/air, solution/alkane vapor and solution/liquid alkane interfaces. It is shown that the adsorption characteristics can be described at all three interfaces by the same thermodynamic approach. In the presence of alkane molecules (in the liquid alkane phase or in the alkane vapor phase) the CnTAB adsorption layers can be best described by a co-adsorption of the alkane molecules.
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Affiliation(s)
- V B Fainerman
- Donetsk Medical University, 16 Ilych Avenue, Donetsk 83003, Ukraine
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66
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Pinaud F, Geisel K, Massé P, Catargi B, Isa L, Richtering W, Ravaine V, Schmitt V. Adsorption of microgels at an oil-water interface: correlation between packing and 2D elasticity. SOFT MATTER 2014; 10:6963-6974. [PMID: 24825608 DOI: 10.1039/c4sm00562g] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The aim of this paper is to determine how microgels adsorb at a model oil-water interface and how they adapt their conformation to compression, which gives rise to surface elasticity depending on the microgel packing. The structure of the film is determined by the Langmuir films approach (forced compression) and compared to spontaneous adsorption using the pendant drop method. The behaviour of microgels differs significantly from that of non-deformable particles but resembles that of linear polymers or proteins. We also correlate the properties of microgels spontaneously adsorbed at model interfaces to their forced adsorption during emulsification. Finally we propose a route to easily control a posteriori the microgel packing at the surface of droplets and the flow properties of emulsions stabilised by the microgels.
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Affiliation(s)
- Florent Pinaud
- Université de Bordeaux, Institut des Sciences Moléculaires, ENSCBP, 16 Av. Pey Berland, 33607 Pessac Cedex, France.
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67
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Deleurence R, Parneix C, Monteux C. Mixtures of latex particles and the surfactant of opposite charge used as interface stabilizers--influence of particle contact angle, zeta potential, flocculation and shear energy. SOFT MATTER 2014; 10:7088-7095. [PMID: 25008289 DOI: 10.1039/c4sm00237g] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We investigate the stabilization of air-water interfaces by mixtures of negatively charged latex particles (sulfate polystyrene) and cationic surfactants (alkyl trimethylammonium bromides). First we report results concerning the binding of surfactant molecules to the latex particles. As the surfactant concentration increases, the charge of the particles reverses, from negative to positive, because CnTAB first binds electrostatically to the latex particles and then through hydrophobic interaction with the monolayer already adsorbed on the particles as well as directly with the hydrophobic surface of the latex. Over a large range of surfactant concentrations around the charge inversion, a strong flocculation is observed and 100 μm large aggregates form in the suspension. Unlike previous studies published on mixtures of inorganic particles with oppositely charged surfactants, we show that we can vary the sign of the zeta potential of the particles without changing the contact angle of the particles over a large range of surfactant concentrations. Indeed, the latex particles that we study are more hydrophobic than inorganic particles, hence adding moderate concentrations of the surfactant results in a weak variation of the contact angle while the charge of the particles can be reversed. This enables decoupling of the effect of zeta potential and contact angle on the interfacial properties of the mixtures. Our study shows that the contact angle and the charge of the particles are not sufficient parameters to control the foam properties, and the key-parameters are the flocculation state and the shear energy applied to produce the foam. Indeed, flocculated samples, whatever the sign of the zeta potential, enable production of a stable armour at the interface. The large aggregates do not adsorb spontaneously at the interface because of their large size, however when a large shear energy is used to produce the foam very stable foam is obtained, where particles are trapped at interfaces. We suggest that the large aggregates may be broken during shear and may reform at the interface to form a solid armour. A simple calculation taking into account the adsorption dynamics of the aggregates as a function of their size is consistent with this hypothesis.
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Affiliation(s)
- Rémi Deleurence
- Soft Matter Science and Engineering UMR7615 UPMC/CNRS/ESPCI ParisTech, 10 rue Vauquelin, 75231 Paris, France.
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68
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Noskov BA, Yazhgur PA, Liggieri L, Lin SY, Loglio G, Miller R, Ravera F. Dilational rheology of spread and adsorbed layers of silica nanoparticles at the liquid-gas interface. COLLOID JOURNAL 2014. [DOI: 10.1134/s1061933x14020057] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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69
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Particle laden fluid interfaces: dynamics and interfacial rheology. Adv Colloid Interface Sci 2014; 206:303-19. [PMID: 24200090 DOI: 10.1016/j.cis.2013.10.010] [Citation(s) in RCA: 122] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 10/09/2013] [Accepted: 10/10/2013] [Indexed: 12/30/2022]
Abstract
We review the dynamics of particle laden interfaces, both particle monolayers and particle+surfactant monolayers. We also discuss the use of the Brownian motion of microparticles trapped at fluid interfaces for measuring the shear rheology of surfactant and polymer monolayers. We describe the basic concepts of interfacial rheology and the different experimental methods for measuring both dilational and shear surface complex moduli over a broad range of frequencies, with emphasis in the micro-rheology methods. In the case of particles trapped at interfaces the calculation of the diffusion coefficient from the Brownian trajectories of the particles is calculated as a function of particle surface concentration. We describe in detail the calculation in the case of subdiffusive particle dynamics. A comprehensive review of dilational and shear rheology of particle monolayers and particle+surfactant monolayers is presented. Finally the advantages and current open problems of the use of the Brownian motion of microparticles for calculating the shear complex modulus of monolayers are described in detail.
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70
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Rio E, Drenckhan W, Salonen A, Langevin D. Unusually stable liquid foams. Adv Colloid Interface Sci 2014; 205:74-86. [PMID: 24342735 DOI: 10.1016/j.cis.2013.10.023] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 10/21/2013] [Accepted: 10/21/2013] [Indexed: 11/28/2022]
Abstract
Obtaining stable liquid foams is an important issue in view of their numerous applications. In some of these, the liquid foam in itself is of interest, in others, the liquid foam acts as a precursor for the generation of solid foam. In this short review, we will make a survey of the existing results in the area. This will include foams stabilised by surfactants, proteins and particles. The origin of the stability is related to the slowing down of coarsening, drainage or coalescence, and eventually to their arrest. The three effects are frequently coupled and in many cases, they act simultaneously and enhance one another. Drainage can be arrested if the liquid of the foam either gels or solidifies. Coalescence is slowed down by gelified foam films, and it can be arrested if the films become very thick and/or rigid. These mechanisms are thus qualitatively easy to identify, but they are less easy to model in order to obtain quantitative predictions. The slowing down of coarsening requests either very thick or small films, and its arrest was observed in cases where the surface compression modulus was large. The detail of the mechanisms at play remains unclear.
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Affiliation(s)
- Emmanuelle Rio
- Laboratoire de Physique des Solides, Université Paris-Sud 11, UMR CNRS 8502, Bâtiment 510, 91405 Orsay Cedex, France
| | - Wiebke Drenckhan
- Laboratoire de Physique des Solides, Université Paris-Sud 11, UMR CNRS 8502, Bâtiment 510, 91405 Orsay Cedex, France
| | - Anniina Salonen
- Laboratoire de Physique des Solides, Université Paris-Sud 11, UMR CNRS 8502, Bâtiment 510, 91405 Orsay Cedex, France
| | - Dominique Langevin
- Laboratoire de Physique des Solides, Université Paris-Sud 11, UMR CNRS 8502, Bâtiment 510, 91405 Orsay Cedex, France
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71
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Blockage of coalescence of water droplets in asphaltenes solutions: A jamming perspective. Colloids Surf A Physicochem Eng Asp 2014. [DOI: 10.1016/j.colsurfa.2013.12.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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72
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Haller PD, Bradley LC, Gupta M. Effect of surface tension, viscosity, and process conditions on polymer morphology deposited at the liquid-vapor interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:11640-5. [PMID: 24007385 DOI: 10.1021/la402538e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
We have observed that the vapor-phase deposition of polymers onto liquid substrates can result in the formation of polymer films or particles at the liquid-vapor interface. In this study, we demonstrate the relationship between the polymer morphology at the liquid-vapor interface and the surface tension interaction between the liquid and polymer, the liquid viscosity, the deposition rate, and the deposition time. We show that the thermodynamically stable morphology is determined by the surface tension interaction between the liquid and the polymer. Stable polymer films form when it is energetically favorable for the polymer to spread over the surface of the liquid, whereas polymer particles form when it is energetically favorable for the polymer to aggregate. For systems that do not strongly favor spreading or aggregation, we observe that the initial morphology depends on the deposition rate. Particles form at low deposition rates, whereas unstable films form at high deposition rates. We also observe a transition from particle formation to unstable film formation when we increase the viscosity of the liquid or increase the deposition time. Our results provide a fundamental understanding about polymer growth at the liquid-vapor interface and can offer insight into the growth of other materials on liquid surfaces. The ability to systematically tune morphology can enable the production of particles for applications in photonics, electronics, and drug delivery and films for applications in sensing and separations.
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Affiliation(s)
- Patrick D Haller
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California , Los Angeles, California, 90089, United States
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73
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Hanazawa T, Murray BS. Effect of oil droplets and their solid/liquid composition on the phase separation of protein-polysaccharide mixtures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:9841-9848. [PMID: 23805874 DOI: 10.1021/la401595u] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The phase separation of a model system consisting of sodium caseinate + xanthan ± a low fraction (up to 3 wt %) of an oil-in-water emulsion was studied at room temperature (20-25 °C). The composition of the oil phase was either 100 wt % n-tetradecane (TD); 50% TD + 50% eicosane (EC) or 100% EC. The droplets in these three "emulsions" were therefore totally liquid, partially solid, and totally solid, respectively. In the presence of 22 mM CaCl2, the mixed TD+EC droplets were most effective at inhibiting phase separation, while the EC emulsions could not prevent phase separation at all. At 32 mM CaCl2 the emulsions tended to promote phase separation, possibly due to enhanced calcium ion-induced droplet aggregation. The apparent interfacial viscosity (ηi) between two macroscopically separated phases was also measured. In the presence of the semisolid mixed droplets ηi = 25 mN s m(-1), significantly higher than ηi with the pure (liquid) TD droplets (15 mN s m(-1)) or with the pure solid EC droplets (12 mN s m(-1)) or in the absence of droplets (<3 mN s m(-1)). Confocal microscopy showed that the microstructure of the phase separating regions also depended upon the composition of the oil droplets, and it is tentatively suggested that the more marked effects of the mixed emulsion droplets were due to them forming a stronger network at the interface via partial coalescence. Control of the extent of interfacial aggregation of droplets is therefore possibly one way to influence the course of phase separation in biopolymer mixtures.
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Affiliation(s)
- Tomohito Hanazawa
- Milk Science Research Institute, Megmilk Snow Brand Co., Ltd., 1-1-2, Minamidai, Kawagoe, Saitama, 350-1165, Japan
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74
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Luu XC, Yu J, Striolo A. Nanoparticles adsorbed at the water/oil interface: coverage and composition effects on structure and diffusion. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:7221-8. [PMID: 23472643 DOI: 10.1021/la304828u] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Dissipative particle dynamics simulations are performed to study the structural and dynamical properties of various systems of nanoparticles accumulated at the water/oil interface. Homogeneous and Janus nanoparticles with different surface compositions are studied. For all nanoparticles, as the surface density increases, a transition from a liquidlike to a solidlike state is observed, as expected. At a high density of nanoparticles, hexagonal structures emerge and the nanoparticles' self-diffusion coefficient decreases because of caging effects. Similar results are observed for nanoparticles with different surface chemistry. Because different nanoparticles have different contact angles at the water/oil interface, the results obtained for systems containing mixed nanoparticles are more interesting. For example, our results show that the self-diffusion coefficient is not a monotonic function of the system composition, caused by the complex relation between hydrodynamic interactions and effective nanoparticle-nanoparticle interactions.
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Affiliation(s)
- Xuan-Cuong Luu
- School of Chemical, Biological, and Materials Engineering, The University of Oklahoma, Norman, Oklahoma 73019, United States
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75
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Kobayashi T, Kawaguchi M. Surface dilational moduli of latex-particle monolayers spread at air-water interface. J Colloid Interface Sci 2012; 390:147-50. [PMID: 23084558 DOI: 10.1016/j.jcis.2012.09.050] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 09/18/2012] [Accepted: 09/20/2012] [Indexed: 11/27/2022]
Abstract
Latex particles prepared by radical dispersion polymerization of styrene and diacetone acrylamide (DAAM) in the presence of potassium persulfate as an initiator were spread as particle monolayers at the air-water interface. The surface pressure isotherms of the latex-particle monolayers are almost reversible during the compression-expansion cycles. The surface dilational moduli of the latex-particle monolayers at a fixed surface pressure of 20 mN/m and a fixed frequency of 10 mHz are almost independent of the strain. Moreover, at a fixed strain of 10% and fixed surface pressures of 10 or 15 mN/m the surface dilational moduli of the latex particle monolayers were measured as a function of frequency. The Lissajous orbits of the latex-particle monolayers exhibit positive hysteresis loops for all surface pressure ranges examined. The crossover between the magnitude of the surface elastic modulus and the magnitude of the surface viscous modulus occurs between the frequencies of 10 and 12 mHz and beyond the frequency of 12 mHz the former is larger than the latter. Such crossover indicates that the strain response of the latex-particle monolayers behave changes from liquid-like viscoelastic behavior to solid-like behavior with increasing frequency.
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Affiliation(s)
- Toshio Kobayashi
- Division of Chemistry for Materials, Graduate School of Engineering, Mie University, Tsu, Mie, Japan
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76
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Golemanov K, Tcholakova S, Denkov N, Pelan E, Stoyanov SD. Surface shear rheology of saponin adsorption layers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:12071-84. [PMID: 22830458 DOI: 10.1021/la302150j] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Saponins are a wide class of natural surfactants, with molecules containing a rigid hydrophobic group (triterpenoid or steroid), connected via glycoside bonds to hydrophilic oligosaccharide chains. These surfactants are very good foam stabiliziers and emulsifiers, and show a range of nontrivial biological activities. The molecular mechanisms behind these unusual properties are unknown, and, therefore, the saponins have attracted significant research interest in recent years. In our previous study (Stanimirova et al. Langmuir 2011, 27, 12486-12498), we showed that the triterpenoid saponins extracted from Quillaja saponaria plant (Quillaja saponins) formed adsorption layers with unusually high surface dilatational elasticity, 280 ± 30 mN/m. In this Article, we study the shear rheological properties of the adsorption layers of Quillaja saponins. In addition, we study the surface shear rheological properties of Yucca saponins, which are of steroid type. The experimental results show that the adsorption layers of Yucca saponins exhibit purely viscous rheological response, even at the lowest shear stress applied, whereas the adsorption layers of Quillaja saponins behave like a viscoelastic two-dimensional body. For Quillaja saponins, a single master curve describes the data for the viscoelastic creep compliance versus deformation time, up to a certain critical value of the applied shear stress. Above this value, the layer compliance increases, and the adsorption layers eventually transform into viscous ones. The experimental creep-recovery curves for the viscoelastic layers are fitted very well by compound Voigt rheological model. The obtained results are discussed from the viewpoint of the layer structure and the possible molecular mechanisms, governing the rheological response of the saponin adsorption layers.
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Affiliation(s)
- Konstantin Golemanov
- Department of Chemical Engineering, Faculty of Chemistry and Pharmacy, Sofia University, Sofia, Bulgaria
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77
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Imperiali L, Liao KH, Clasen C, Fransaer J, Macosko CW, Vermant J. Interfacial rheology and structure of tiled graphene oxide sheets. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:7990-8000. [PMID: 22432592 DOI: 10.1021/la300597n] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The hydrophilic nature of graphene oxide sheets can be tailored by varying the carbon to oxygen ratio. Depending on this ratio, the particles can be deposited at either a water-air or a water-oil interface. Upon compression of thus-created Langmuir monolayers, the sheets cover the entire interface, assembling into a strong, compact layer of tiled graphene oxide sheets. With further compression, the particle layer forms wrinkles that are reversible upon expansion, resembling the behavior of an elastic membrane. In the present work, we investigate under which conditions the structure and properties of the interfacial layer are such that free-standing films can be obtained. The interfacial rheological properties of these films are investigated using both compressional experiments and shear rheometry. The role of surface rheology in potential applications of such tiled films is explored. The rheological properties are shown to be responsible for the efficiency of such layers in stabilizing water-oil emulsions. Moreover, because of the mechanical integrity, large-area monolayers can be deposited by, for example, Langmuir-Blodgett techniques using aqueous subphases. These films can be turned into transparent conductive films upon subsequent chemical reduction.
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Affiliation(s)
- Luna Imperiali
- Department of Chemical Engineering, KU Leuven, University of Leuven, Leuven, Belgium
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78
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Effect of hydrophobicity on tensile rheological properties of silica nanoparticle monolayers at the air–water interface. Colloids Surf A Physicochem Eng Asp 2012. [DOI: 10.1016/j.colsurfa.2011.12.047] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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79
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Skelhon TS, Grossiord N, Morgan AR, Bon SAF. Quiescent water-in-oil Pickering emulsions as a route toward healthier fruit juice infused chocolate confectionary. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm34233b] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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80
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Vandewalle N, Caps H, Delon G, Saint-Jalmes A, Rio E, Saulnier L, Adler M, Biance AL, Pitois O, Addad SC, Hohler R, Weaire D, Hutzler S, Langevin D. Foam stability in microgravity. ACTA ACUST UNITED AC 2011. [DOI: 10.1088/1742-6596/327/1/012024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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81
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Zang D, Rio E, Delon G, Langevin D, Wei B, Binks B. Influence of the contact angle of silica nanoparticles at the air–water interface on the mechanical properties of the layers composed of these particles. Mol Phys 2011. [DOI: 10.1080/00268976.2010.542778] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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82
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Ma H, Perea B, Dai LL. Study of two-component colloidal particles at air/water interfaces using Langmuir–Blodgett techniques. Colloids Surf A Physicochem Eng Asp 2010. [DOI: 10.1016/j.colsurfa.2010.09.035] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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83
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Pingali K, Mendez R, Lewis D, Michniak-Kohn B, Cuitiño A, Muzzio F. Evaluation of strain-induced hydrophobicity of pharmaceutical blends and its effect on drug release rate under multiple compression conditions. Drug Dev Ind Pharm 2010; 37:428-35. [PMID: 20942612 DOI: 10.3109/03639045.2010.521160] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE The purpose of this study was to investigate the effect of mechanical shear on hydrophobicity of pharmaceutical powder blends as a function of composition and particle size, and to determine the impact on drug release from tablets. METHODS Four powder formulations were subjected to three different shear strain conditions (40 rev, 160 rev, and 640 rev) in a controlled shear environment operating at a shear rate of 80 rpm. A total of 12 blends were tested for hydrophobicity. Subsequently, sheared blends were compressed into tablets at 8 kN and 12 kN in a rotary tablet press. During tablet compression, powder samples were collected after the feed frame and their hydrophobicity was again measured. RESULTS Results indicated that increase in shear strain could significantly increase hydrophobicity, predominantly as an interacting function of blend composition. Blends with both colloidal silica and magnesium stearate (MgSt) were found to show higher hydrophobicity with shear than other blends. Additional shear applied by the tablet press feed frame was found to change the powder hydrophobicity only in the absence of MgSt. CONCLUSIONS Studies showed that the drug release rates dropped with shear more for the blends with both colloidal silica and MgSt than the other blends. Furthermore, the rate of drug release dropped with a decrease in particle size of the main excipient. Surprisingly, the relationship between the relative increase in hydrophobicity and a corresponding drop in the drug release rate was not found when either MgSt or colloidal silica was mixed alone in the blends.
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Affiliation(s)
- Kalyana Pingali
- Department of Chemical and Biochemical Engineering, Rutgers University, 98 Brett Road, Piscataway, NJ 08854, USA
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84
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Bardosova M, Pemble ME, Povey IM, Tredgold RH. The langmuir-blodgett approach to making colloidal photonic crystals from silica spheres. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2010; 22:3104-24. [PMID: 20589747 DOI: 10.1002/adma.200903708] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The area of colloidal photonic crystal research has attracted enormous attention in recent years as a result of the potential of such materials to provide the means of fabricating new or improved photonic devices. As an area where chemistry still predominates over engineering the field is still in its infancy in terms of finding real applications being limited by ease of fabrication, reproducibility and 'quality'- for example the extent to which ordered structures may be prepared over large areas. It is our contention that the Langmuir-Blodgett assembly method when applied to colloidal particles of silica and perhaps other materials, offers a way of overcoming these issues. To this end the assembly of silica and other particles into colloidal photonic crystals using the Langmuir-Blodgett (LB) method is described and some of the numerous papers on this topic, which have been published, are reviewed. It is shown that the layer-by-layer control of photonic crystal growth afforded by the LB method allows for the fabrication of a range of novel, layered photonic crystals that may not be easily assembled using any other approach. Some of the more interesting of these structures, including so-called heterostructured photonic crystals comprising of layers of spheres having different diameters are presented and their optical properties described. Finally, we offer our comments as to future applications of this interesting technology.
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85
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Santini E, Ravera F, Ferrari M, Alfè M, Ciajolo A, Liggieri L. Interfacial properties of carbon particulate-laden liquid interfaces and stability of related foams and emulsions. Colloids Surf A Physicochem Eng Asp 2010. [DOI: 10.1016/j.colsurfa.2010.01.041] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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86
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87
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Liggieri L, Miller R. Relaxation of surfactants adsorption layers at liquid interfaces. Curr Opin Colloid Interface Sci 2010. [DOI: 10.1016/j.cocis.2010.02.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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88
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89
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Danov KD, Kralchevsky PA. Capillary forces between particles at a liquid interface: general theoretical approach and interactions between capillary multipoles. Adv Colloid Interface Sci 2010; 154:91-103. [PMID: 20170895 DOI: 10.1016/j.cis.2010.01.010] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Revised: 01/18/2010] [Accepted: 01/28/2010] [Indexed: 11/16/2022]
Abstract
The liquid interface around an adsorbed colloidal particle can be undulated because of roughness or heterogeneity of the particle surface, or due to the fact that the particle has non-spherical (e.g. ellipsoidal or polyhedral) shape. In such case, the meniscus around the particle can be expanded in Fourier series, which is equivalent to a superposition of capillary multipoles, viz. capillary charges, dipoles, quadrupoles, etc. The capillary multipoles attract a growing interest because their interactions have been found to influence the self-assembly of particles at liquid interfaces, as well as the interfacial rheology and the properties of particle-stabilized emulsions and foams. As a rule, the interfacial deformation in the middle between two adsorbed colloidal particles is small. This fact is utilized for derivation of accurate asymptotic expressions for calculating the capillary forces by integration in the midplane, where the Young-Laplace equation can be linearized and the superposition approximation can be applied. Thus, we derived a general integral expression for the capillary force, which was further applied to obtain convenient asymptotic formulas for the force and energy of interaction between capillary multipoles of arbitrary orders. The new analytical expressions have a wider range of validity in comparison with the previously published ones. They are applicable not only for interparticle distances that are much smaller than the capillary length, but also for distances that are comparable or greater than the capillary length.
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Affiliation(s)
- Krassimir D Danov
- Department of Chemical Engineering, Faculty of Chemistry, University of Sofia, 1164 Sofia, Bulgaria
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90
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Zang DY, Rio E, Langevin D, Wei B, Binks BP. Viscoelastic properties of silica nanoparticle monolayers at the air-water interface. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2010; 31:125-134. [PMID: 20151313 DOI: 10.1140/epje/i2010-10565-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Revised: 12/04/2009] [Indexed: 05/28/2023]
Abstract
We have investigated the rheological behaviour of silica nanoparticle layers at the air-water interface. Both compressed and deposited layers have been studied in Langmuir troughs and with a bicone rheometer. The compressed layers are more homogeneous and rigid, and the elastic response to continuous, step and oscillatory compression are similar, provided the compression is fast enough and relaxation is prevented. The deposited layers are less rigid and more viscoelastic. Their shear moduli deduced from the oscillatory uniaxial compression are much smaller than those deduced from pure shear deformation suggesting that the effective shear rate is smaller than expected in the compression measurements.
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Affiliation(s)
- D Y Zang
- Laboratoire de Physique des Solides, Université Paris-Sud, UMR CNRS 8502, Bâtiment 510, 91405, Orsay cedex, France
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91
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Maestro A, Langevin D, Monroy F. Amorphous freezing in two dimensions: from soft coils to rigid particles. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2010; 31:89-94. [PMID: 20101518 DOI: 10.1140/epje/i2010-10554-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2009] [Revised: 11/17/2009] [Accepted: 12/10/2009] [Indexed: 05/28/2023]
Abstract
The topic of the gel transition in two dimensions is revisited by considering data on the shear elasticity of Langmuir monolayers of different spherical objects. Amorphous freezing can be associated to structural percolation in a lattice able to resist shear stresses. The shear modulus and its dependence on the packing fraction are found to strongly depend on the details of the interaction potential and largely differ from expectations for entropic networks. This behaviour can be interpreted in terms of more elaborated percolation theories including central forces and bond-bending forces.
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Affiliation(s)
- A Maestro
- Departamento de Química Física I, Universidad Complutense, Madrid, Spain
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92
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Zang D, Langevin D, Binks BP, Wei B. Shearing particle monolayers: strain-rate frequency superposition. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2010; 81:011604. [PMID: 20365381 DOI: 10.1103/physreve.81.011604] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 07/16/2009] [Indexed: 05/29/2023]
Abstract
We report surface shear rheological measurements on monolayers of silica nanoparticles at the air-water interface. We have used the method of strain-rate frequency superposition (SRFS) to characterize the structural relaxation. We show that the rheological properties of the layers have the same universal linear and nonlinear behavior as three-dimensional soft materials. We also discuss the original healing properties of these monolayers.
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Affiliation(s)
- Duyang Zang
- Laboratoire de Physique des Solides, Université Paris Sud and UMR CNRS, Orsay, France
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93
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Silica nanoparticle sols. Part 3: Monitoring the state of agglomeration at the air/water interface using the Langmuir–Blodgett technique. J Colloid Interface Sci 2009; 336:584-91. [DOI: 10.1016/j.jcis.2009.04.039] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2009] [Revised: 04/07/2009] [Accepted: 04/08/2009] [Indexed: 11/24/2022]
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94
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Cheng HL, Velankar SS. Controlled jamming of particle-laden interfaces using a spinning drop tensiometer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:4412-4420. [PMID: 19275131 DOI: 10.1021/la803552j] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
When particles adsorb at a fluid/fluid interface at a sufficiently high concentration, the interface loses mobility and displays solidlike characteristics, a phenomenon called "interfacial jamming". Jamming can arrest interfacial tension-driven morphological coarsening in liquid/liquid or gas/liquid systems and therefore stabilize two phase morphologies with unusual interfacial shapes, for example, nonspherical drops and bubbles, and bijels. Here, we conduct a systematic study of interfacial tension-driven jamming of a particle monolayer using a spinning drop tensiometer (SDT). A drop of mineral oil surrounded by ethylene glycol was spun into a cylindrical shape in a SDT. With decreasing rotational rate, the cylindrical drop retracted due to interfacial tension, thus reducing the interfacial area. In the case of particle-covered drops, drop retraction caused an increase in interfacial particle concentration. Accordingly, when the specific interfacial area became comparable to that of a close packing of particles, interfacial jamming occurred and drop retraction was arrested. Fast interfacial contraction or low particle loadings led to less compact jammed monolayers, that is, with a larger specific interfacial area. There was also significant hysteresis between compressing versus expanding the jammed monolayer, suggesting that a certain minimum stress is required for unjamming. Limited experiments with the same particles at a mineral oil/silicone oil interface showed altogether different behavior. In this case, particles did not spread at the interface and a particle-free portion of the interface coexisted with a particle-covered portion. This suggests that the monolayer behavior at this nonpolar/nonpolar interface is dominated by interparticle attraction.
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Affiliation(s)
- Hsin-Ling Cheng
- Department of Chemical Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
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95
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Industrial manufactured silica nanoparticle sols. 2: Surface tension, particle concentration, foam generation and stability. Colloids Surf A Physicochem Eng Asp 2009. [DOI: 10.1016/j.colsurfa.2008.12.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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96
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Effect of esterically bonded agents on the monolayer structure and foamability of nano-silica. Colloids Surf A Physicochem Eng Asp 2009. [DOI: 10.1016/j.colsurfa.2008.10.039] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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97
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Zang D, Stocco A, Langevin D, Wei B, Binks BP. An ellipsometry study of silica nanoparticle layers at the water surface. Phys Chem Chem Phys 2009; 11:9522-9. [DOI: 10.1039/b907903c] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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98
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Cervantes Martinez A, Rio E, Delon G, Saint-Jalmes A, Langevin D, Binks BP. On the origin of the remarkable stability of aqueous foams stabilised by nanoparticles: link with microscopic surface properties. SOFT MATTER 2008; 4:1531-1535. [PMID: 32907121 DOI: 10.1039/b804177f] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We have performed a quantitative study of the coarsening of foams stabilised by partially hydrophobic silica nanoparticles. We have used a variety of techniques: optical and electron microscopy, microfluidics, and multiple light scattering. Using earlier studies of planar particle monolayers, we have been able to correlate the interfacial properties and the macroscopic temporal evolution of the foam. This has shed light on the origin of the absence of coarsening of particle-stabilised foams. Such particle-stabilised foams appear to be the only known foam system where coarsening is inhibited by surface elasticity.
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Affiliation(s)
- A Cervantes Martinez
- Laboratoire de Physique des Solides, UMR CNRS 8502, Université Paris Sud, 91405, Orsay, France
| | - E Rio
- Laboratoire de Physique des Solides, UMR CNRS 8502, Université Paris Sud, 91405, Orsay, France
| | - G Delon
- Laboratoire de Physique des Solides, UMR CNRS 8502, Université Paris Sud, 91405, Orsay, France
| | - A Saint-Jalmes
- Institut de Physique de Rennes, UMR 6251, Université Rennes 1, Rennes, 35042, France
| | - D Langevin
- Laboratoire de Physique des Solides, UMR CNRS 8502, Université Paris Sud, 91405, Orsay, France
| | - B P Binks
- Surfactant & Colloid Group, Department of Chemistry, University of Hull, Hull, HU6 7RX, UK
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99
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Langevin D. Aqueous Foams: A Field of Investigation at the Frontier Between Chemistry and Physics. Chemphyschem 2008; 9:510-22. [DOI: 10.1002/cphc.200700675] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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