101
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Effects of nanoparticles on the morphology of immiscible polymer blends – Challenges and opportunities. Eur Polym J 2016. [DOI: 10.1016/j.eurpolymj.2016.02.023] [Citation(s) in RCA: 141] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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102
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103
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Wang J, Nguyen AV. Foam drainage in the presence of solid particles. SOFT MATTER 2016; 12:3004-3012. [PMID: 26877265 DOI: 10.1039/c6sm00028b] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We conducted forced drainage experiments to study the liquid flow within the foams stabilized by a cationic surfactant (CTAB) in the presence of partially hydrophobic silica particles. The results show that the presence of solid particles, even when present in small amounts (0.0932 g L(-1) foam), can significantly decrease the foam permeability. The scaling behaviour (power law) between the drainage velocity and the imposed flow rate indicates that the presence of solid particles in the foams triggers a transition of the foam drainage regime from a node-dominated regime to a Plateau border-dominated regime. We applied two foam drainage equations for aqueous foams to simulate the experimental data and interpret the transition. The simulation results show that the presence of solid particles in the foams increases the rigidity of the interfaces and the viscous losses in the channels (the Plateau borders) of the foams, and decreases the foam permeability. We also generalize the theory for the effects of unattached hydrophilic particles on foam drainage by considering the effects of hydrophobicity and concentration of solid particles on the confinement of foam networks. This study explores liquid drainage in three-phase foams and is relevant to the field of hydrophobic particle separation by froth flotation, in which the wash water is commonly applied to the froth layer to improve the product grade.
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Affiliation(s)
- J Wang
- School of Chemical Engineering, The University of Queensland, Brisbane, Queensland 4072, Australia.
| | - A V Nguyen
- School of Chemical Engineering, The University of Queensland, Brisbane, Queensland 4072, Australia.
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104
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Wang J, Nguyen AV, Farrokhpay S. A critical review of the growth, drainage and collapse of foams. Adv Colloid Interface Sci 2016; 228:55-70. [PMID: 26718078 DOI: 10.1016/j.cis.2015.11.009] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 11/23/2015] [Accepted: 11/25/2015] [Indexed: 10/22/2022]
Abstract
This review focuses on the current knowledge regarding (i) the mechanisms governing foamability and foam stability, and (ii) models for the foam column kinetics. Although different length scales of foam structure, such as air-water interface and liquid film, have been studied to elucidate the mechanisms that control the foamability and foam stability, many questions remain unanswered. It is due to the collective effects of different mechanisms involved and the complicated structures of foam sub-structures such as foam films, Plateau borders and nodes, and foam networks like soft porous materials. The current knowledge of the effects of solid particles on liquid film stability and foam drainage is also discussed to highlight gaps in our present level of understanding foam systems with solid particles. We also critically review and summarize the models that describe macroscopic foam behaviors, such as equilibrium foam height, foam growth and collapse, within the context of the mechanisms involved.
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105
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Huang S, Gawlitza K, von Klitzing R, Gilson L, Nowak J, Odenbach S, Steffen W, Auernhammer GK. Microgels at the Water/Oil Interface: In Situ Observation of Structural Aging and Two-Dimensional Magnetic Bead Microrheology. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:712-722. [PMID: 26704516 DOI: 10.1021/acs.langmuir.5b01438] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Stimuli-responsive microgels can be used as stabilizers for emulsions. However, the details of structure and the viscoelastic property of the microgel-laden interface are still not well-known. We synthesized fluorescently labeled microgels and used confocal microscopy to observe their arrangement at the water/oil interface. The microgels aggregated spontaneously at the interface, and the aggregated structure reorganized due to thermal motion. The structure of the interfacial layer formed by microgels depended on the microgel concentration at the interface. We suggest that the structure was controlled by the aggregation and adsorption of microgels at the interface. The interparticle separation between microgels at the interface decreased over time, implying a slow aging process of the microgels at the interface. Magnetic beads were introduced at the interface and used to trigger deformation of the microgel layer. Under compression and shear the microgels in the aggregated structure rearranged, leading to plastic deformation, and some elastic responses were also observed.
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Affiliation(s)
- Shilin Huang
- Max Planck Institute for Polymer Research , Ackermannweg 10, 55128 Mainz, Germany
| | - Kornelia Gawlitza
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Technische Universität Berlin , Strasse des 17. Juni 124, 10623 Berlin, Germany
| | - Regine von Klitzing
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Technische Universität Berlin , Strasse des 17. Juni 124, 10623 Berlin, Germany
| | - Laurent Gilson
- Max Planck Institute for Polymer Research , Ackermannweg 10, 55128 Mainz, Germany
| | - Johannes Nowak
- Chair of Magnetofluiddynamics, Measuring and Automation Technology, Institute of Fluid Mechanics, Technische Universität Dresden , 01069 Dresden, Germany
| | - Stefan Odenbach
- Chair of Magnetofluiddynamics, Measuring and Automation Technology, Institute of Fluid Mechanics, Technische Universität Dresden , 01069 Dresden, Germany
| | - Werner Steffen
- Max Planck Institute for Polymer Research , Ackermannweg 10, 55128 Mainz, Germany
| | - Günter K Auernhammer
- Max Planck Institute for Polymer Research , Ackermannweg 10, 55128 Mainz, Germany
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106
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Pan M, Kim M, Blauch L, Tang SKY. Surface-functionalizable amphiphilic nanoparticles for pickering emulsions with designer fluid–fluid interfaces. RSC Adv 2016. [DOI: 10.1039/c6ra03950b] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
This work describes the synthesis of amphiphilic silica nanoparticles with functionalizable surfaces for stabilizing aqueous drops in fluorinated oils, and for enabling the generation of emulsions with tailored interfacial properties.
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Affiliation(s)
- Ming Pan
- Department of Materials Science and Engineering
- Stanford University
- Stanford
- USA
| | - Minkyu Kim
- Department of Mechanical Engineering
- Stanford University
- Stanford
- USA
| | - Lucas Blauch
- Department of Mechanical Engineering
- Stanford University
- Stanford
- USA
| | - Sindy K. Y. Tang
- Department of Mechanical Engineering
- Stanford University
- Stanford
- USA
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107
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Effect of silica nanoparticles on the interfacial properties of a canonical lipid mixture. Colloids Surf B Biointerfaces 2015; 136:971-80. [DOI: 10.1016/j.colsurfb.2015.11.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 10/19/2015] [Accepted: 11/02/2015] [Indexed: 12/23/2022]
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108
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Farzi GA, Nejad AP. An Image-Based Technique for Measuring Droplet Size Distribution: The Use of CNN Algorithm. J DISPER SCI TECHNOL 2015. [DOI: 10.1080/01932691.2015.1090321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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109
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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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110
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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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111
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Sabapathy M, Kollabattula V, Basavaraj MG, Mani E. Visualization of the equilibrium position of colloidal particles at fluid-water interfaces by deposition of nanoparticles. NANOSCALE 2015; 7:13868-13876. [PMID: 26172860 DOI: 10.1039/c5nr03369a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We present a general yet simple method to measure the contact angle of colloidal particles at fluid-water interfaces. In this method, the particles are spread at the required fluid-water interface as a monolayer. In the water phase a chemical reaction involving reduction of a metal salt such as aurochloric acid is initiated. The metal grows as a thin film or islands of nanoparticles on the particle surface exposed to the water side of the interface. Analyzing the images of particles by high resolution scanning microscopy (HRSEM), we trace the three phase contact line up to which deposition of the metal film occurs. From geometrical relations, the three phase contact angle is then calculated. We report the measurements of the contact angle of silica and polystyrene (PS) particles at different interfaces such as air-water, decane-water and octanol-water. We have also applied this method to measure the contact angle of surfactant treated polystyrene particles at the air-water interface, and we find a non-monotonic change of the contact angle with the concentration of the surfactant. Our results are compared with the well-known gel trapping technique and we find good comparison with previous measurements.
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Affiliation(s)
- Manigandan Sabapathy
- Polymer Engineering and Colloid Science Laboratory, Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai -600 036, India.
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112
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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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113
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Danov KD, Kralchevsky PA, Radulova GM, Basheva ES, Stoyanov SD, Pelan EG. Shear rheology of mixed protein adsorption layers vs their structure studied by surface force measurements. Adv Colloid Interface Sci 2015; 222:148-61. [PMID: 24828304 DOI: 10.1016/j.cis.2014.04.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Accepted: 04/20/2014] [Indexed: 11/30/2022]
Abstract
The hydrophobins are proteins that form the most rigid adsorption layers at liquid interfaces in comparison with all other investigated proteins. The mixing of hydrophobin HFBII with other conventional proteins is expected to reduce the surface shear elasticity and viscosity, E(sh) and η(sh), proportional to the fraction of the conventional protein. However, the experiments show that the effect of mixing can be rather different depending on the nature of the additive. If the additive is a globular protein, like β-lactoglobulin and ovalbumin, the surface rigidity is preserved, and even enhanced. The experiments with separate foam films indicate that this is due to the formation of a bilayer structure at the air/water interface. The more hydrophobic HFBII forms the upper layer adjacent to the air phase, whereas the conventional globular protein forms the lower layer that faces the water phase. Thus, the elastic network formed by the adsorbed hydrophobin remains intact, and even reinforced by the adjacent layer of globular protein. In contrast, the addition of the disordered protein β-casein leads to softening of the HFBII adsorption layer. Similar (an even stronger) effect is produced by the nonionic surfactant Tween 20. This can be explained with the penetration of the hydrophobic tails of β-casein and Tween 20 between the HFBII molecules at the interface, which breaks the integrity of the hydrophobin interfacial elastic network. The analyzed experimental data for the surface shear rheology of various protein adsorption layers comply with a viscoelastic thixotropic model, which allows one to determine E(sh) and η(sh) from the measured storage and loss moduli, G' and G″. The results could contribute for quantitative characterization and deeper understanding of the factors that control the surface rigidity of protein adsorption layers with potential application for the creation of stable foams and emulsions with fine bubbles or droplets.
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Affiliation(s)
- Krassimir D Danov
- Department of Chemical Engineering, Faculty of Chemistry and Pharmacy, Sofia University, 1164 Sofia, Bulgaria
| | - Peter A Kralchevsky
- Department of Chemical Engineering, Faculty of Chemistry and Pharmacy, Sofia University, 1164 Sofia, Bulgaria.
| | - Gergana M Radulova
- Department of Chemical Engineering, Faculty of Chemistry and Pharmacy, Sofia University, 1164 Sofia, Bulgaria
| | - Elka S Basheva
- Department of Chemical Engineering, Faculty of Chemistry and Pharmacy, Sofia University, 1164 Sofia, Bulgaria
| | - Simeon D Stoyanov
- Unilever Research & Development, 3133AT Vlaardingen, The Netherlands; Laboratory of Physical Chemistry and Colloid Science, Wageningen University, 6703HB Wageningen, The Netherlands
| | - Eddie G Pelan
- Unilever Research & Development, 3133AT Vlaardingen, The Netherlands
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114
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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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115
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116
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Merkel T, Henne J, Hecht L, Gräf V, Walz E, Schuchmann HP. Emulsification of particle loaded drops in simple shear flow. Colloids Surf A Physicochem Eng Asp 2015. [DOI: 10.1016/j.colsurfa.2015.01.080] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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117
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Morioka T, Kawaguchi M. Surface dilational moduli of polymer and blended polymer monolayers spread at air-water interfaces. Adv Colloid Interface Sci 2014; 214:1-16. [PMID: 25456455 DOI: 10.1016/j.cis.2014.10.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 10/07/2014] [Accepted: 10/07/2014] [Indexed: 11/17/2022]
Abstract
Surface dilational moduli of polymer monolayers, blended polymer monolayers, and polymer particle monolayers spread at air-water interfaces are reviewed, focusing on measurements using surface pressure isotherm, surface pressure relaxation, and oscillating barrier methods. Differences between the surface dilational moduli of condensed polymer monolayers and expanded polymer monolayers are explored. Moreover, the features of the surface dilational moduli in blended polymer monolayers are discussed in terms of their miscibility.
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Affiliation(s)
- Takako Morioka
- Division of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya, Tsu, Mie 514-8507, Japan
| | - Masami Kawaguchi
- Division of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya, Tsu, Mie 514-8507, Japan.
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118
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Karbaschi M, Lotfi M, Krägel J, Javadi A, Bastani D, Miller R. Rheology of interfacial layers. Curr Opin Colloid Interface Sci 2014. [DOI: 10.1016/j.cocis.2014.08.003] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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119
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120
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Lishchuk SV. Effective surface dilatational viscosity of highly concentrated particle-laden interfaces. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 90:053005. [PMID: 25493879 DOI: 10.1103/physreve.90.053005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Indexed: 06/04/2023]
Abstract
The effective surface dilatational viscosity is calculated of a flat interface separating two immiscible fluids laden with half-immersed monodisperse rigid spherical non-Brownian particles in the limit of high particle concentration. The derivation is based upon the facts that (i) highly concentrated particle arrays in a plane form a hexagonal structure and (ii) the dominant contribution to the viscous dissipation rate arises in the thin gaps between neighboring particles.
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Affiliation(s)
- S V Lishchuk
- Department of Mathematics, University of Leicester, Leicester LE1 7RH, United Kingdom
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121
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Santini E, Guzmán E, Ferrari M, Liggieri L. Emulsions stabilized by the interaction of silica nanoparticles and palmitic acid at the water–hexane interface. Colloids Surf A Physicochem Eng Asp 2014. [DOI: 10.1016/j.colsurfa.2014.02.054] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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122
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Stanimirova RD, Marinova KG, Danov KD, Kralchevsky PA, Basheva ES, Stoyanov SD, Pelan EG. Competitive adsorption of the protein hydrophobin and an ionic surfactant: Parallel vs sequential adsorption and dilatational rheology. Colloids Surf A Physicochem Eng Asp 2014. [DOI: 10.1016/j.colsurfa.2014.06.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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123
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Du X, Zhao L, Xiao H, Liang F, Chen H, Wang X, Wang J, Qu W, Lei Z. Stability and shear thixotropy of multilayered film foam. Colloid Polym Sci 2014. [DOI: 10.1007/s00396-014-3361-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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124
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Barman S, Christopher GF. Simultaneous interfacial rheology and microstructure measurement of densely aggregated particle laden interfaces using a modified double wall ring interfacial rheometer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:9752-9760. [PMID: 25068732 DOI: 10.1021/la502329s] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The study of particle laden interfaces has increased significantly due to the increasing industrial use of particle stabilized foams and Pickering emulsions, whose bulk rheology and stability are highly dependent on particle laden interface's interfacial rheology, which is a function of interfacial microstructure. To understand the physical mechanisms that dictate interfacial rheology of particle laden interfaces requires correlating rheology to microstructure. To achieve this goal, a double wall ring interfacial rheometer has been modified to allow real time, simultaneous interfacial visualization and shear rheology measurements. The development of this tool is outlined, and its ability to provide novel and unique measurements is demonstrated on a sample system. This tool has been used to examine the role of microstructure on the steady shear rheology of densely packed, aggregated particle laden interfaces at three surface concentrations. Through examination of the rheology and analysis of interfacial microstructure response to shear, a transition from shear thinning due to aggregated cluster breakup to yielding at a slip plane within the interface has been identified. Interestingly, it is found that aggregated interfaces transition to yielding well before they reached a jammed state. Furthermore, these systems undergo significant shear induced order when densely packed. These results indicate that the mechanics of these interfaces are not simply jammed or unjammed and that the interfacial rheology relationship with microstructure can give us significant insight into understanding how to engineer particle laden interfaces in the future. By examining both rheology and microstructure, the mechanisms that dictate observed rheology are now understood and can be used to predict and control the rheology of the interface.
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Affiliation(s)
- Sourav Barman
- Department of Mechanical Engineering, Texas Tech University , Lubbock, Texas 79409-1021, United States
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125
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Maestro A, Guzmán E, Ortega F, Rubio RG. Contact angle of micro- and nanoparticles at fluid interfaces. Curr Opin Colloid Interface Sci 2014. [DOI: 10.1016/j.cocis.2014.04.008] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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126
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Lotfi M, Karbaschi M, Javadi A, Mucic N, Krägel J, Kovalchuk V, Rubio R, Fainerman V, Miller R. Dynamics of liquid interfaces under various types of external perturbations. Curr Opin Colloid Interface Sci 2014. [DOI: 10.1016/j.cocis.2014.04.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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127
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Lishchuk SV. Effective surface-shear viscosity of an incompressible particle-laden fluid interface. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 89:043003. [PMID: 24827328 DOI: 10.1103/physreve.89.043003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Indexed: 06/03/2023]
Abstract
The presence of even a small amount of surfactant at the particle-laden fluid interface subjected to shear makes surface flow incompressible if the shear rate is small enough [T. M. Fischer et al., J. Fluid Mech. 558, 451 (2006)]. In the present paper the effective surface shear viscosity of a flat, low-concentration, particle-laden incompressible interface separating two immiscible fluids is calculated. The resulting value is found to be 7.6% larger than the value obtained without account for surface incompressibility.
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Affiliation(s)
- S V Lishchuk
- Department of Mathematics, University of Leicester, Leicester LE1 7RH, United Kingdom
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