1
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Wang S, Zhou B, Yang X, Niu L, Li S. Tannic acid enhanced the emulsion stability, rheology and interface characteristics of
Clanis Bilineata Tingtauica Mell
protein stabilised oil‐in‐water emulsion. Int J Food Sci Technol 2022. [DOI: 10.1111/ijfs.15839] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Shuya Wang
- Engineering Research Center of Bio‐process, Ministry of Education/Key Laboratory for Agricultural Products Processing of Anhui Province, School of Food and Biological Engineering Hefei University of Technology Hefei 230601 China
- Key Laboratory of Fermentation Engineering, Ministry of Education/School of Food and Biological Engineering Hubei University of Technology Wuhan 430068 China
| | - Bin Zhou
- Key Laboratory of Fermentation Engineering, Ministry of Education/School of Food and Biological Engineering Hubei University of Technology Wuhan 430068 China
| | - Xinquan Yang
- School of Life Sciences Guangzhou University Guangzhou 511442 China
| | - Liqiong Niu
- School of Life Sciences Guangzhou University Guangzhou 511442 China
| | - Shugang Li
- Engineering Research Center of Bio‐process, Ministry of Education/Key Laboratory for Agricultural Products Processing of Anhui Province, School of Food and Biological Engineering Hefei University of Technology Hefei 230601 China
- Key Laboratory of Fermentation Engineering, Ministry of Education/School of Food and Biological Engineering Hubei University of Technology Wuhan 430068 China
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2
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Langevin D. Light scattering by liquid surfaces, new developments. Adv Colloid Interface Sci 2021; 289:102368. [PMID: 33561568 DOI: 10.1016/j.cis.2021.102368] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 11/25/2022]
Abstract
The surface light scattering technique is presented, highlighting recent technical improvements and describing studies of various types of surfaces. The technique is non-invasive, but delicate to handle and no commercial instruments are available yet. The technique gives however interesting information difficult to obtain otherwise, for instance on out-of-equilibrium surfaces, surfaces of very low tension, or systems close to solidification. Many studies were performed with monolayers of surface-active molecules at the surface of water. In this case, surface viscoelastic parameters can be determined at high frequencies (10 kHz- 1 MHz), complementing usefully the data obtained at lower frequencies with other techniques. As with these other techniques, inconsistencies such as negative surface viscosities are sometimes reported. The origin of these anomalies is not yet fully clarified. The problem deserves further work, in order to achieve a satisfactory description of the motion of surfactant or polymer-laden surfaces.
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3
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In honor to Ramón G. Rubio on the occasion of his 65th birthday. Adv Colloid Interface Sci 2020; 282:102202. [PMID: 32663706 DOI: 10.1016/j.cis.2020.102202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This Honorary Note is dedicated to the 65th birthday of Ramón G. Rubio and summarizes some of his contributions to the current knowledge in the science and technology of colloids and interfaces. Since 1995, Ramón González Rubio is Full Professor at the Complutense University of Madrid (Spain) where he has developed an extensive research activity in different scientific and technological aspects related to colloidal systems and interfacial phenomena: from particle-laden interfaces to polyelectrolyte multilayers, including the kinetics of simultaneous spreading and evaporation of solutions (and dispersions) and interfacial rheology. This broad research activity has contributed to some of the most recent advances in colloid and interface science, which is reflected in more than 200 papers in peer-reviewed journals and more than 4000 citations according to the Web of Science.
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4
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Arriaga LR, Rodríguez-García R, Moleiro LH, Prévost S, López-Montero I, Hellweg T, Monroy F. Dissipative dynamics of fluid lipid membranes enriched in cholesterol. Adv Colloid Interface Sci 2017; 247:514-520. [PMID: 28755780 DOI: 10.1016/j.cis.2017.07.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Revised: 07/08/2017] [Accepted: 07/08/2017] [Indexed: 01/26/2023]
Abstract
Cholesterol is an intriguing component of fluid lipid membranes: It makes them stiffer but also more fluid. Despite the enormous biological significance of this complex dynamical behavior, which blends aspects of membrane elasticity with viscous friction, their mechanical bases remain however poorly understood. Here, we show that the incorporation of physiologically relevant contents of cholesterol in model fluid membranes produces a fourfold increase in the membrane bending modulus. However, the increase in the compression rigidity that we measure is only twofold; this indicates that cholesterol increases coupling between the two membrane leaflets. In addition, we show that although cholesterol makes each membrane leaflet more fluid, it increases the friction between the membrane leaflets. This dissipative dynamics causes opposite but advantageous effects over different membrane motions: It allows the membrane to rearrange quickly in the lateral dimension, and to simultaneously dissipate out-of-plane stresses through friction between the two membrane leaflets. Moreover, our results provide a clear correlation between coupling and friction of membrane leaflets. Furthermore, we show that these rigid membranes are optimal to resist slow deformations with minimum energy dissipation; their optimized stability might be exploited to design soft technological microsystems with an encoded mechanics, vesicles or capsules for instance, useful beyond classical applications as model biophysical systems.
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Affiliation(s)
- Laura R Arriaga
- Dpto. Química Física I, Universidad Complutense, E-28040 Madrid, Spain; Translational Biophysics Unit, Instituto de Investigacion Biomédica Hospital Doce de Octubre (i+12), E-28041 Madrid, Spain
| | | | - Lara H Moleiro
- Dpto. Química Física I, Universidad Complutense, E-28040 Madrid, Spain; Translational Biophysics Unit, Instituto de Investigacion Biomédica Hospital Doce de Octubre (i+12), E-28041 Madrid, Spain; Fakultät für Chemie Physikalische und Biophysikalische Chemie (PC III), Universität Bielefeld, Universitätsstr. 25, D-33615 Bielefeld, Germany
| | - Sylvain Prévost
- Institut Laue-Langevin, 71 avenue des Martyrs, F-38042 Grenoble, France; Helmholtz-Center-Berlin, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany; Stranski-Laboratorium, Straße des 17. Juni 124, Technische Universität Berlin, D-10623 Berlin, Germany
| | | | - Thomas Hellweg
- Fakultät für Chemie Physikalische und Biophysikalische Chemie (PC III), Universität Bielefeld, Universitätsstr. 25, D-33615 Bielefeld, Germany
| | - Francisco Monroy
- Dpto. Química Física I, Universidad Complutense, E-28040 Madrid, Spain; Translational Biophysics Unit, Instituto de Investigacion Biomédica Hospital Doce de Octubre (i+12), E-28041 Madrid, Spain.
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5
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Surface dilatational properties of Gemini surfactants containing multiple hydroxyl groups. Colloid Polym Sci 2016. [DOI: 10.1007/s00396-016-3892-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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6
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Sun X, Chen Y, Zhao J. Highly stable aqueous foams generated by fumed silica particles hydrophobised in situ with a quaternary ammonium gemini surfactant. RSC Adv 2016. [DOI: 10.1039/c6ra02063a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Fumed silica hydrophobisedin situwith a quaternary ammonium gemini surfactant was an excellent stabiliser for aqueous foams.
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Affiliation(s)
- Xiaoxiang Sun
- Institute of Colloid and Interface Chemistry
- College of Chemistry and Chemical Engineering
- Fuzhou University
- Fuzhou
- PR China
| | - Yu Chen
- Institute of Colloid and Interface Chemistry
- College of Chemistry and Chemical Engineering
- Fuzhou University
- Fuzhou
- PR China
| | - Jianxi Zhao
- Institute of Colloid and Interface Chemistry
- College of Chemistry and Chemical Engineering
- Fuzhou University
- Fuzhou
- PR China
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7
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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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8
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Noskov BA, Bykov AG. Dilational surface rheology of polymer solutions. RUSSIAN CHEMICAL REVIEWS 2015. [DOI: 10.1070/rcr4518] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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9
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Song BL, Yu XN, Zhao JX, Sun GJ. Highly stable foams generated in mixed systems of ethanediyl-1,2-bis(dodecyldimethylammonium bromide) and alcohols. RSC Adv 2015. [DOI: 10.1039/c5ra16799j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Highly stable foams were generated using a gemini surfactant, ethanediyl-1,2-bis(dodecyldimethylammonium bromide) (12-2-12) together with hexanol (C6OH) or heptanol (C7OH), in aqueous solution. There exists the optimum addition for both alcohols.
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Affiliation(s)
- Bing-Lei Song
- The Key Laboratory of Food Colloids and Biotechnology
- Ministry of Education
- School of Chemical and Material Engineering
- Jiangnan University
- Wuxi
| | - Xiao-Na Yu
- The Key Laboratory of Food Colloids and Biotechnology
- Ministry of Education
- School of Chemical and Material Engineering
- Jiangnan University
- Wuxi
| | - Jian-Xi Zhao
- Institute of Colloid and Interface Chemistry
- College of Chemistry and Chemical Engineering
- Fuzhou University
- Fuzhou
- P. R. China
| | - Guo-Jing Sun
- Institute of Colloid and Interface Chemistry
- College of Chemistry and Chemical Engineering
- Fuzhou University
- Fuzhou
- P. R. China
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10
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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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11
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Sweat DP, Kim M, Schmitt AK, Perroni DV, Fry CG, Mahanthappa MK, Gopalan P. Phase Behavior of Poly(4-hydroxystyrene-block-styrene) Synthesized by Living Anionic Polymerization of an Acetal Protected Monomer. Macromolecules 2014. [DOI: 10.1021/ma501126t] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Daniel P. Sweat
- Department of Chemistry and ‡Department of
Materials Science and Engineering, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Myungwoong Kim
- Department of Chemistry and ‡Department of
Materials Science and Engineering, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Adam K. Schmitt
- Department of Chemistry and ‡Department of
Materials Science and Engineering, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Dominic V. Perroni
- Department of Chemistry and ‡Department of
Materials Science and Engineering, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Charles G. Fry
- Department of Chemistry and ‡Department of
Materials Science and Engineering, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Mahesh K. Mahanthappa
- Department of Chemistry and ‡Department of
Materials Science and Engineering, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Padma Gopalan
- Department of Chemistry and ‡Department of
Materials Science and Engineering, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
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12
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Wang W, Murthy NS, Kuzmenko I, Anderson NA, Vaknin D. Structure of biodegradable films at aqueous surfaces: X-ray diffraction and spectroscopy studies of polylactides and tyrosine-derived polycarbonates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:11420-30. [PMID: 23919814 PMCID: PMC3842024 DOI: 10.1021/la401268s] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Three representative polymers of increasing modulus, poly(d,l-lactic acid), PDLLA, poly(desaminotyrosyl-tyrosine ethyl ester carbonate), PDTEC, and the same polymer with iodinated DTE segments, PI2DTEC, were characterized by surface-pressure versus area (Π-A) isotherms and surface sensitive X-ray diffraction techniques. Films of 10-100 Å thickness were prepared for these studies by spreading dilute polymer solutions at air-water interfaces. The general properties of the isotherms and the Flory exponents, determined from the isotherms, vary in accordance with the increasing modulus of PDLLA, PDTEC, PI2DTEC, respectively. The analysis of in situ X-ray reflectivity and grazing incidence X-ray diffraction (GIXD) measurements from films at aqueous surfaces provides a morphological picture that is consistent with the modulus of the polymers, and to a large extent, with their packing in their dry-bulk state. Large absorption of X-rays by iodine enabled X-ray spectroscopic studies under near-total-reflection conditions to determine the iodine distribution in the PI2DTEC film and complement the structural model derived from reflectivity and GIXD. These structural studies lay the foundation for future studies of polymer-protein interactions at aqueous interfaces.
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13
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Mixed DPPC-cholesterol Langmuir monolayers in presence of hydrophilic silica nanoparticles. Colloids Surf B Biointerfaces 2013; 105:284-93. [PMID: 23384691 DOI: 10.1016/j.colsurfb.2013.01.020] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Revised: 12/19/2012] [Accepted: 01/10/2013] [Indexed: 01/14/2023]
Abstract
Langmuir monolayers of Cholesterol (Chol) and a mixture of Chol with 1,2-Dipalmitoyl-sn-glycerol-3-phosphocholine (DPPC), at a ratio of 17:83 in weight, spread on pure water and on silica nanoparticle dispersions, have been investigated measuring the compression isotherms as well as the surface pressure response to harmonic area variation of the monolayer. Aim of this study was to evaluate the effects of the interaction of silica nanoparticles with Chol and the conditions for the incorporation in the monolayer. In previous works on different kind of lipid monolayers, it has been shown that hydrophilic silica nanoparticles dispersed in the sub-phase may transfer into the monolayer, driven by the interaction with the lipid molecules that make them partially hydrophobic. The results here obtained indicate that also for Chol and Chol-DPPC mixtures the presence of silica nanoparticles may have important effects on the phase behaviour and structural properties of the monolayer. As confirmed by complementary structural characterisations, BAM, AFM and ellipsometry, the principal effect of the nanoparticle incorporation is the disruption of the monolayer packing, owing to the alteration of the cohesive interactions of lipid components.
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14
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Zhang H, Xu G, Liu T, Xu L, Zhou Y. Foam and interfacial properties of Tween 20–bovine serum albumin systems. Colloids Surf A Physicochem Eng Asp 2013. [DOI: 10.1016/j.colsurfa.2012.10.028] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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15
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Santini E, Guzmán E, Ravera F, Ferrari M, Liggieri L. Properties and structure of interfacial layers formed by hydrophilic silica dispersions and palmitic acid. Phys Chem Chem Phys 2011; 14:607-15. [PMID: 22089250 DOI: 10.1039/c1cp22552a] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The properties and structure of different types of interfacial layers obtained from aqueous dispersions of nanometric silica and palmitic acid (PA) have been studied and characterized by different diagnostics and measurements. The investigations concern PA monolayers spread on the silica dispersions, dispersions in contact with PA solutions in oil and silica dispersions containing PA, aiming at elucidating the role of the PA interaction with the particles and investigating the surface-activity of the originated silica-PA complexes. Drop shape tensiometry was utilized to measure the dynamic surface and interfacial tension while a Langmuir trough apparatus was used to obtain compression isotherms of the spread PA layers and to measure the dilational viscoelasticity according to the oscillating barrier method. Brewster angle microscopy and ellipsometry were utilized to investigate the lateral and vertical structure of the interfacial layers. From this multifold approach emerges a complex picture of the features of these interfacial layers that can be rationalized on the basis of the adsorption of PA on the particle surface. The results evidence a threshold in PA adsorption above which particles change from hydrophilic to partially hydrophobic, promoting their incorporation into the interfacial layer.
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Affiliation(s)
- Eva Santini
- CNR-Istituto per l'Energetica e le Interfasi, Genova, Italy
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16
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Interfacial dilational viscoelasticity and foam stability in quaternary ammonium gemini surfactant systems: influence of intermolecular hydrogen bonding. Colloid Polym Sci 2011. [DOI: 10.1007/s00396-011-2425-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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17
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Maestro A, Ortega F, Rubio RG, Rubio MA, Krägel J, Miller R. Rheology of poly(methyl methacrylate) Langmuir monolayers: Percolation transition to a soft glasslike system. J Chem Phys 2011; 134:104704. [DOI: 10.1063/1.3560612] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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18
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Langevin D, Monroy F. Interfacial rheology of polyelectrolytes and polymer monolayers at the air–water interface. Curr Opin Colloid Interface Sci 2010. [DOI: 10.1016/j.cocis.2010.02.002] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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19
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Arriaga LR, López-Montero I, Ignés-Mullol J, Monroy F. Domain-Growth Kinetic Origin of Nonhorizontal Phase Coexistence Plateaux in Langmuir Monolayers: Compression Rigidity of a Raft-Like Lipid Distribution. J Phys Chem B 2010; 114:4509-20. [DOI: 10.1021/jp9118953] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Laura R. Arriaga
- Mechanics of Biological Membranes and Biorheology, Departamento de Química Física I, Universidad Complutense de Madrid, 28040 Madrid, Spain, and Departamento de Química Física, Universidad de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
| | - Iván López-Montero
- Mechanics of Biological Membranes and Biorheology, Departamento de Química Física I, Universidad Complutense de Madrid, 28040 Madrid, Spain, and Departamento de Química Física, Universidad de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
| | - Jordi Ignés-Mullol
- Mechanics of Biological Membranes and Biorheology, Departamento de Química Física I, Universidad Complutense de Madrid, 28040 Madrid, Spain, and Departamento de Química Física, Universidad de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
| | - Francisco Monroy
- Mechanics of Biological Membranes and Biorheology, Departamento de Química Física I, Universidad Complutense de Madrid, 28040 Madrid, Spain, and Departamento de Química Física, Universidad de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
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20
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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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21
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Marze S. Relaxation processes of PGPR at the water/oil interface inferred by oscillatory or transient viscoelasticity measurements. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:12066-12072. [PMID: 19764774 DOI: 10.1021/la9016849] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The rheological properties of PolyGlycerol PolyRicinoleate (PGPR) at the oil/water interface were studied using a drop-shaped tensiometer. Small deformation oscillations of the drop area allow the measurement of the interfacial viscoelasticity spectrum, that is, the elastic and viscous moduli as a function of frequency. Another way to obtain such a spectrum is to perform a transient relaxation measurement from which the relaxation modulus as a function of time is deduced and interpreted. Several models containing one or more relaxation times were considered, and their resulting spectra were compared to the oscillatory ones. Similar results suggest that one could in principle use oscillatory or transient relaxations indifferently. However, the transient relaxation technique proved to be more adapted for the determination of the relaxation times. At low PGPR concentrations in oil, the behavior is controlled by long relaxation times, whereas short ones take over when approaching and exceeding the saturation interfacial concentration. This was understood as a shift from a diffusion-dominated regime to a rearrangements-dominated regime.
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Affiliation(s)
- Sébastien Marze
- Nestlé Research Center, Vers-chez-les-Blanc, CH-1000 Lausanne 26, Switzerland.
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22
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Hilles HM, Ritacco H, Monroy F, Ortega F, Rubio RG. Temperature and concentration effects on the equilibrium and dynamic behavior of a Langmuir monolayer: from fluid to gel-like behavior. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:11528-11532. [PMID: 19489588 DOI: 10.1021/la9014515] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The equilibrium isotherms of monolayers of poly(4-hydroxystyrene) on the air/water interface have been studied in the 5-60 degrees C range. The results indicate that the interface is a poor solvent for the monolayers over the whole temperature range. For surface pressures within the semidilute regime, the plot of the area occupied by the polymer coils versus temperature at constant surface pressure shows a sharp change of slope near 30 degrees C. Also, the surface excess entropy shows a similar change of slope at the same temperature. The surface shear viscosity can be described by a power law of the surface concentration. Within the semidilute regime, the exponent of the power law changes. The temperature dependence of the viscosity points out a change from independent particle to collective dynamics.
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Affiliation(s)
- Hani M Hilles
- Departamento de Química Física I, Facultad de Química, Universidad Complutense, 28040-Madrid, Spain
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23
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Guzmán E, Ritacco H, Ortega F, Svitova T, Radke CJ, Rubio RG. Adsorption kinetics and mechanical properties of ultrathin polyelectrolyte multilayers: liquid-supported versus solid-supported films. J Phys Chem B 2009; 113:7128-37. [PMID: 19438276 DOI: 10.1021/jp811178a] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Multilayers of sodium salt of poly(4-styrene sulfonate) (PSS) and poly(diallyl dimethyl ammonium) chloride (PDADMAC) have been built layer by layer (LbL) both at the solid/aqueous interface (solid supported) and the air/aqueous interface (liquid supported). For the solid-supported multilayers, the adsorption kinetics and the complex shear modulus were measured using a dissipative quartz crystal microbalance and a null ellipsometer. A bubble tensiometer was used to measure the adsorption kinetics and the elasticity modulus of the liquid-supported multilayers. At the solid/aqueous interface, adsorption kinetics changes with the number of adsorbed layers. However, at the air/aqueous interface, PSS dynamics were the same for all adsorbed layers except the first. Conversely, the adsorption kinetics of PDADMAC at the air/water surface differed between those layers close to the interface and those far from it. Multilayers grow at the air/water interface by an intrinsic-charge-compensation process, whereas, for the same ionic strengths, solid-supported layers deposit by the extrinsic-charge-compensation process. No significant differences were found between the recoverable dilational storage modulus of the liquid-supported multilayers and the real part of the shear modulus of the solid-supported ones built at the same ionic strength. The values of the modulus are in the MPa range, which corresponds to gel-like films. This result is in agreement with the strong hydration degree of the LbL films calculated from ellipsometry measurements.
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Affiliation(s)
- Eduardo Guzmán
- Departamento de Química Física I, Facultad de Química, Universidad Complutense, 28040 Madrid, Spain
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Delgado C, Merchán MD, Velázquez MM. Effect of the Addition of Polyelectrolytes on Monolayers of Carboxybetaines. J Phys Chem B 2008; 112:687-93. [DOI: 10.1021/jp075249i] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Cristina Delgado
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad de Salamanca, 37008 Salamanca, Spain
| | - M. Dolores Merchán
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad de Salamanca, 37008 Salamanca, Spain
| | - M. Mercedes Velázquez
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad de Salamanca, 37008 Salamanca, Spain
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25
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Monroy F, Ortega F, Rubio RG, Velarde MG. Surface rheology, equilibrium and dynamic features at interfaces, with emphasis on efficient tools for probing polymer dynamics at interfaces. Adv Colloid Interface Sci 2007; 134-135:175-89. [PMID: 17559785 DOI: 10.1016/j.cis.2007.04.023] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Adequately probing interfacial or (free) surface waves offers the possibility of exploring qualitative and quantitative equilibrium and rheological features hence large scale and long time dynamics. Several experimental techniques are briefly reviewed. The combination of capillary waves experiments with methods based on analyzing the mechanical deformation of the surface allows to explore dynamics from the microsecond scale up to collective phenomena relaxing at very long times, seconds, minutes or even hours. Results related to the scaling behavior of insoluble polymer films, and to the existence of a glass transition in quasi-2D systems are also discussed.
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Affiliation(s)
- Francisco Monroy
- Departamento de Química Física I, Facultad de CC. Químicas, Universidad Complutense, Ciudad Universitaria s/n, 28040 Madrid, Spain
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26
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El-Sadek RI, Roushdy M, Magda JJ. Low-frequency dilational elasticity of the nematic 4'-pentyl-4-biphenylcarbonitrile (5CB)/water interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:7907-10. [PMID: 17567161 DOI: 10.1021/la700864k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Axisymmetric oscillating pendant drop shape analysis has been used to study the interfacial rheology of the liquid crystal 4'-pentyl-4-biphenylcarbonitrile (5CB) in water with homeotropic anchoring. Nearly spherical 5CB droplets were subjected to low frequency (1-5 mHz) volume oscillations, and the increase in tension with surface dilation was used to calculate the complex modulus. The droplet interface response is completely elastic, with no relaxations occurring on the experimental time scale. This surprising result is attributed to droplet storage of elastic energy in the form of distorted orientational distributions within the bulk (Frank elasticity) and on the surface (anchoring elasticity).
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27
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Cicuta P. Compression and shear surface rheology in spread layers of β-casein and β-lactoglobulin. J Colloid Interface Sci 2007; 308:93-9. [PMID: 17234202 DOI: 10.1016/j.jcis.2006.12.056] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Revised: 12/04/2006] [Accepted: 12/08/2006] [Indexed: 11/30/2022]
Abstract
We investigate the surface viscoelasticity of beta-lactoglobulin and beta-casein spread surface monolayers using a recently discovered method. Step compressions are performed, and the surface pressure is measured as a function of time. This is a common experiment for surface monolayers. However in our experiments the pressure is recorded by two perpendicular sensors, parallel and perpendicular to the compression direction. This enables us to clearly measure the time relaxation of both the compression and shear moduli, at the same time, in a single experiment, and with a standard apparatus. beta-Lactoglobulin and beta-casein monolayers are interesting because of their importance in food science and because they exhibit universally slow dynamical behavior that is still not fully understood. Our results confirm that the compressional modulus dominates the total viscoelastic response in both proteins. Indeed for beta-casein we confirm that the shear modulus is always negligible, i.e., the layer is in a fluid state. In beta-lactoglobulin a finite shear modulus emerges above a critical concentration. We emphasize that in Langmuir trough dynamic experiments the surface pressure should be measured in both the compression and the perpendicular directions.
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Affiliation(s)
- Pietro Cicuta
- Cavendish Laboratory and Nanoscience Center, J.J. Thomson Avenue, Cambridge CB3 0HE, UK.
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28
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Hilles H, Maestro A, Monroy F, Ortega F, Rubio RG, Velarde MG. Polymer monolayers with a small viscoelastic linear regime: Equilibrium and rheology of poly(octadecyl acrylate) and poly(vinyl stearate). J Chem Phys 2007; 126:124904. [PMID: 17411158 DOI: 10.1063/1.2714514] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The equilibrium properties of monolayers of two polymers: poly(octadecyl acrylate) and poly(vinyl stearate) on water have been measured. The surface pressure (Pi) versus surface concentration (Gamma) curves indicate that the water-air interface is a poor solvent for both polymers. The thermal expansivity shows a sharp change near room temperature. This behavior is typical of a glass transition; this is the first time that such a plot is observed for Langmuir films. The Pi vs Gamma curves measured by the continuous compression method show strong anisotropy effects. They also show that the monolayer is brought into nonequilibrium states depending on the compression rate. Within the linear regime, the relaxation experiments were bimodal. The longest relaxation time strongly increases as T is decreased, which might be compatible with the high increase of viscosity in the glass transition. The oscillatory barrier experiments showed that the maximum strain of the linear regime is smaller than 3% for both monolayers. The Fourier-transform analysis of the oscillatory experiments beyond the linear regime points out the contribution of different harmonics in the response function. Oscillations in the nonlinear regime show hysteresis cycles. The results obtained indicate that some of the previously published data for these polymer monolayers correspond to nonequilibrium states.
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Affiliation(s)
- Hani Hilles
- Departamento Química Física I, Facultad Químicas, Universidad Complutense, 28040 Madrid, Spain
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29
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Hilles H, Monroy F, Bonales LJ, Ortega F, Rubio RG. Fourier-transform rheology of polymer Langmuir monolayers: analysis of the non-linear and plastic behaviors. Adv Colloid Interface Sci 2006; 122:67-77. [PMID: 16875640 DOI: 10.1016/j.cis.2006.06.013] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The linear regime (LR) of viscoelastic behavior has been found to be limited to rather small values of strain, well below the strains found in many technological processes. A Fourier-transform method is described for analyzing the surface rheology data obtained in insoluble Langmuir polymer monolayers beyond the LR. In the concentrate regime, the monolayers show a transition from elastic to plastic behavior, which is characterized by high irreversibility. A simple 2-D rubber model is presented that describes the behavior of the monolayers in the non-linear region not too far from the end of the LR.
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Affiliation(s)
- Hani Hilles
- Dept. Química Física I, Fac. Química, Univ. Complutense, 28040-Madrid, Spain
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30
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Hilles HM, Sferrazza M, Monroy F, Ortega F, Rubio RG. Equilibrium and dynamics of Langmuir monolayers when the interface is a selective solvent: Polystyrene-b-poly(t-butyl acrylate) block copolymers. J Chem Phys 2006; 125:074706. [PMID: 16942363 DOI: 10.1063/1.2238868] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The surface pressure of monolayers of insoluble diblock copolymers has been measured. One of the blocks is made of poly(t-butyl acrylate) (PtBA), and the other one by polystyrene (PS). The interface is a good solvent for PtBA, while it is a poor solvent for PS. For the sake of comparison, monolayers of a PtBA homopolymer (good solvent conditions) and of poly(4-hydroxy styrene) (P4HS) (poor solvent conditions) have been also measured. It has been found that the relative length of the blocks plays an important role on the shape of the surface pressure Pi versus surface concentration Gamma curves and also on the shape of the equilibrium compressibility versus Gamma curves. However, it does not affect the maximum value of Pi reached at high Gamma's. Surprisingly, the ellipsometric thickness of the copolymer monolayers is almost independent of the relative length of the blocks. The dynamics of the monolayers has been studied by step compression and by surface-light scattering techniques. When M(w,PtBA) >> M(w,PS) single exponential relaxations are observed. However, stretched exponentials are obtained for M(w,PS) > or = M(w,PtBA). The relaxation times decrease with increasing Gamma for all the copolymers studied. This is the behavior usually found for poor solvent conditions (P4HS) and opposite to that found for homopolymers under good solvent conditions [PtBA, poly(vinylacetate)]. This means that the solvent quality of the interface does not determine the pressure dependence of tau. The elasticity modulus of the monolayers in the kilohertz range takes values that are similar to those of the high-frequency limit of the relaxation experiments. This means that the relaxation processes have characteristic frequencies below 1 Hz.
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Affiliation(s)
- Hani M Hilles
- Departamento Química Física I, Facultad Química, Universidad Complutense, 28040 Madrid, Spain
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31
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Safouane M, Miller R, Möhwald H. Surface viscoelastic properties of floating polyelectrolyte multilayers films: A capillary wave study. J Colloid Interface Sci 2005; 292:86-92. [PMID: 16055144 DOI: 10.1016/j.jcis.2005.05.061] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2005] [Revised: 05/18/2005] [Accepted: 05/21/2005] [Indexed: 11/24/2022]
Abstract
A capillary wave technique was used to study the viscoelastic properties of floating polyelectrolyte multilayers of (PSS/PAH)(n) at the air-water interface. Oppositely charged polyelectrolyte layers were adsorbed onto two different Langmuir monolayers, either the lipid dimethyldioctadecylammonium bromide (DODAB) or the block copolymer poly(styrene-b-sodium acrylate) (PS-b-PAA). The results allow to propose a schematic representation of the multilayers in three zones: Zone I as a precursor, representing the adhesion between the Langmuir monolayer and the bulk polyelectrolyte multilayer. Zone II forms a bulk or core zone of the multilayer. Zone III as an outer zone in direct contact with the aqueous phase. The results show an increase of the elasticity after the formation of four polyelectrolyte layers accompanied by an apparent negative viscosity. This behaviour was interpreted as a translation of elasticity dominance from zone I to zone II. The Young modulus of seven layers was in the same order of magnitude as observed for planar polyelectrolyte multilayer films.
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Affiliation(s)
- M Safouane
- Max Planck Institute of Colloids and Interfaces, D-14476 Potsdam, Germany.
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32
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Klebanau A, Kliabanova N, Ortega F, Monroy F, Rubio RG, Starov V. Equilibrium Behavior and Dilational Rheology of Polyelectrolyte/Insoluble Surfactant Adsorption Films: Didodecyldimethylammonium Bromide and Sodium Poly(styrenesulfonate). J Phys Chem B 2005; 109:18316-23. [PMID: 16853357 DOI: 10.1021/jp051862v] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The surface pressure of monolayers of an insoluble surfactant, didodecyldimethylammonium bromide (DODAB), has been measured onto subphases with different concentrations of poly(styrenesulfonate) (PSS) and at different temperatures. The presence of PSS in the subphase shifts the surface-pressure (Pi) curves to larger areas per DODAB molecule, A, and shifts the surface phase transition to higher Pi's. The presence of PSS chains decreases the surface electric potential; the decrease is higher than expected from the formation of a double layer between the DODAB molecules and the PSS segments. Increasing the temperature shifts the surface-pressure curves to higher areas and also increases the values of Pi of the surface phase transition. The effect of the PSS chains on the Pi versus A curves is contrary to the one induced by the presence of inert electrolytes in the subphase. The behavior is consistent with the existence of a dense layer of PSS segments beneath the DODAB monolayer at low PSS concentrations, c. Two PSS layers exist at higher concentrations, a dense layer immediately below the DODAB and a less-dense layer, below the first one, that protrudes deep into the subphase. The surface-pressure relaxation curves have been found to be bimodal through the whole range of surface pressures and at all the values of polymer concentration studied. These results point out that the adsorption layers behave mainly as elastic bodies, with zero-frequency elasticity, epsilon(omega = 0), which agrees with the equilibrium compressibility modulus. The increase [epsilon(omega = 1) - epsilon(omega = 0)] has been found to be independent of both polymer concentration and molecular weight. The zero-frequency-dilational viscosity, kappa(omega = 0), strongly increases with Pi in the two-dimensional condensed-liquid region. The surface viscosity strongly decreases with increasing frequency; the decreasing rate is higher than the one found for the monolayers of nonionic insoluble polymers. kappa(omega = 0) has also been found to be independent of both polymer concentration and molecular weight. These results seem to indicate that it is the film formed by the DODAB molecules and the first dense polymer layer that determines the surface viscoelastic moduli of this system.
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Affiliation(s)
- Aliaksandr Klebanau
- Departamento de Quimica Fisica I, Facultad de Ciencias Quimicas, Universidad Complutense, 28040 Madrid, Spain
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33
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Monroy F, Ortega F, Rubio RG, Ritacco H, Langevin D. Surface rheology of two-dimensional percolating networks: Langmuir films of polymer pancakes. PHYSICAL REVIEW LETTERS 2005; 95:056103. [PMID: 16090892 DOI: 10.1103/physrevlett.95.056103] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2005] [Indexed: 05/03/2023]
Abstract
We report surface rheological measurements on Langmuir films of submicron-sized polymer coils (pancakes). The dynamics of the sol phase is found to be governed by free volume as in the simplest percolation problem. The observed rheology of the percolated phase (gel-like) is compatible with predictions for compressed arrangements of highly deformed soft particles interacting through their contact interfaces.
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Affiliation(s)
- Francisco Monroy
- Departamento de Química Físca I, Facultad de Química, Universidad Complutense, E-28040 Madrid, Spain.
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34
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Aoki H, Anryu M, Ito S. Two-dimensional polymers investigated by scanning near-field optical microscopy: Conformation of single polymer chain in monolayer. POLYMER 2005. [DOI: 10.1016/j.polymer.2005.05.056] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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35
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Velázquez MM, Ortega F, Monroy F, Rubio RG, Pegiadou S, Pérez L, Infante MR. Langmuir monolayers of the zwitterionic surfactant hexadecyl 1-N-l-tryptophan glycerol ether. J Colloid Interface Sci 2005; 283:144-52. [PMID: 15694435 DOI: 10.1016/j.jcis.2004.08.173] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2003] [Accepted: 08/11/2004] [Indexed: 10/26/2022]
Abstract
We report the formation of Langmuir monolayers of pure zwitterionic hexadecyl 1-N-L-tryptophan glycerol ether (C(16)-TGE) surfactant and mixed monolayers of cationic-zwitterionic surfactant obtained modifying the pH of the subphase. The pressure-area and surface potential-area isotherms and fluorescence microscopy measurements have been used to characterize the surface phase transitions in the monolayers. These transitions appeared at larger areas as the pH decreased from 6.0 to 2.0 and almost disappeared as the pH decreased further. The analysis of the surface potential and the infrared reflection-absorption spectroscopy data suggests that the phase transition is associated with a change of orientation of both the hydrocarbon chain and the aromatic group of the surfactant with respect to the air-water surface. The surface rheology of the monolayers was studied by quasielastic light scattering and by the oscillatory barrier technique. The results indicate that there is at least one relaxation process in the monolayer.
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Affiliation(s)
- M Mercedes Velázquez
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad de Salamanca, 37008 Salamanca, Spain.
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36
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Muñoz MG, Encinar M, Bonales LJ, Ortega F, Monroy F, Rubio RG. Surface Light-Scattering at the Air−Liquid Interface: From Newtonian to Viscoelastic Polymer Solutions. J Phys Chem B 2005; 109:4694-9. [PMID: 16851550 DOI: 10.1021/jp044811r] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The dynamics of the liquid-air interface of aqueous solutions of a tensioactive triblock copolymer (Pluronic F-68) has been studied using surface quasielastic light scattering over a broad range of concentrations and temperatures. Ancillary surface tension and bulk rheometry data have been obtained for the same system. The results show that the classical theoretical spectrum for monolayers on a Newtonian fluid can be applied only for concentrations below 4.10(-2) mM. For concentrations above c = 14 mM a clear peak centered at zero frequency appears in the spectrum. This feature is incompatible with the classical theoretical spectrum. The SQELS spectra have been described in terms of the theory of Wang and Huang [Wang, C. H.; Huang, Q. R. J. Chem. Phys. 1997, 107, 5898] considering that the loss modulus of the concentrated solutions shows the existence of two relaxation modes even at low frequencies. The theory is able to explain the existence of a peak centered at zero frequency in the spectra, and the theoretical spectra point out the existence of an elastic peak together with the capillary one. There is a reasonable agreement between the relaxation times and the product Gtau obtained from the fits of the SQELS spectra to the theory of Wang and Huang and those obtained from bulk rheology.
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Affiliation(s)
- Mercedes G Muñoz
- Department Química Física I, Fac. Química, University Complutense, 28040-Madrid, Spain
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37
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Freer EM, Yim KS, Fuller GG, Radke CJ. Shear and dilatational relaxation mechanisms of globular and flexible proteins at the hexadecane/water interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:10159-10167. [PMID: 15518508 DOI: 10.1021/la0485226] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Proteins adsorbed at fluid/fluid interfaces influence many phenomena: food emulsion and foam stability (Murray et al. Langmuir 2002, 18, 9476 and Borbas et al. Colloids Surf., A 2003, 213, 93), two-phase enzyme catalysis (Cascao-Pereira et al. Biotechnol. Bioeng. 2003, 83, 498; 2002, 78, 595), human lung function (Lunkenheimer et al. Colloids Surf., A 1996, 114, 199; Wustneck et al.; and Banerjee et al. 2000, 15, 14), and cell membrane mechanical properties (Mohandas et al. 1994, 23, 787). Time scales important to these phenomena are broad, necessitating an understanding of the dynamics of biological macromolecules at interfaces. We utilize interfacial shear and dilatational deformations to study the rheology of a globular protein, lysozyme, and a disordered protein, beta-casein, at the hexadecane/water interface. Linear viscoelastic properties are measured using small amplitude oscillatory flow, stress relaxation after a sudden dilatational displacement, and shear creep response to probe the rheological response over broad experimental time scales. Our studies of lysozyme and beta-casein reveal that the interfacial dissipation mechanisms are strongly coupled to changes in the protein structure upon and after adsorption. For beta-casein, the interfacial response is fluidlike in shear deformation and is dominated by interfacial viscous dissipation, particularly at low frequencies. Conversely, the dilatational response of beta-casein is dominated by diffusion dissipation at low frequencies and viscous dissipation at higher frequencies (i.e., when the experimental time scale is faster than the characteristic time for diffusion). For lysozyme in shear deformation, the adsorbed protein layer is primarily elastic with only a weak frequency dependence. Similarly, the interfacial dilatational moduli change very little with frequency. In comparison to beta-casein, the frequency response of lysozyme does not change substantially after washing the protein from the bulk solution. Apparently, it is the irreversibly adsorbed fraction that dominates the dynamic rheological response for lysozyme. Using stress relaxation after a sudden dilatational displacement and shear creep response, the characteristic time of relaxation was found to be 1000 s in both modes of deformation. The very long relaxation time for lysozyme likely results from the formation of a glassy interfacial network. This network develops at high interfacial concentrations where the molecules are highly constrained because of conformation changes that prevent desorption.
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Affiliation(s)
- Erik M Freer
- Chemical Engineering Department, University of California, Berkeley, California 94720-1462, USA
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38
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Monteux C, Fuller GG, Bergeron V. Shear and Dilational Surface Rheology of Oppositely Charged Polyelectrolyte/Surfactant Microgels Adsorbed at the Air−Water Interface. Influence on Foam Stability. J Phys Chem B 2004. [DOI: 10.1021/jp047462+] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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39
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Hilles HM, Ortega F, Rubio RG, Monroy F. Long-time relaxation dynamics of langmuir films of a glass-forming polymer: evidence of glasslike dynamics in two dimensions. PHYSICAL REVIEW LETTERS 2004; 92:255503. [PMID: 15245024 DOI: 10.1103/physrevlett.92.255503] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2003] [Indexed: 05/24/2023]
Abstract
We have carried out an experimental study on the mechanical relaxation of Langmuir films of a glass-forming polymer, poly-(4-hydroxystyrene), a good example of a two-dimensional system made of condensed polymer coils (at poor-solvent conditions). This study allows us to explore the response functions of the film and the temperature and density dependencies of the relaxation time. The dynamical properties show glasslike features (non-Debye mechanical response and non-Arrhenius relaxation times) reconcilable within the frame of the mode-coupling model.
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Affiliation(s)
- Hani M Hilles
- Departamento de Química Física I, Facultad de Química, Universidad Complutense, Ciudad Universitaria s/n, E28040 Madrid, Spain
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40
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Freer EM, Yim KS, Fuller GG, Radke CJ. Interfacial Rheology of Globular and Flexible Proteins at the Hexadecane/Water Interface: Comparison of Shear and Dilatation Deformation. J Phys Chem B 2004. [DOI: 10.1021/jp037236k] [Citation(s) in RCA: 229] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Erik M. Freer
- Chemical Engineering Department, University of California, Berkeley, California 94720-1462, and Chemical Engineering Department, Stanford University, Stanford, California 94305-5025
| | - Kang Sub Yim
- Chemical Engineering Department, University of California, Berkeley, California 94720-1462, and Chemical Engineering Department, Stanford University, Stanford, California 94305-5025
| | - Gerald G. Fuller
- Chemical Engineering Department, University of California, Berkeley, California 94720-1462, and Chemical Engineering Department, Stanford University, Stanford, California 94305-5025
| | - Clayton J. Radke
- Chemical Engineering Department, University of California, Berkeley, California 94720-1462, and Chemical Engineering Department, Stanford University, Stanford, California 94305-5025
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41
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Cicuta P, Hopkinson I. Recent developments of surface light scattering as a tool for optical-rheology of polymer monolayers. Colloids Surf A Physicochem Eng Asp 2004. [DOI: 10.1016/j.colsurfa.2003.11.025] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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42
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43
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Noskov BA, Akentiev AV, Bilibin AY, Zorin IM, Miller R. Dilational surface viscoelasticity of polymer solutions. Adv Colloid Interface Sci 2003; 104:245-71. [PMID: 12818499 DOI: 10.1016/s0001-8686(03)00045-9] [Citation(s) in RCA: 146] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A review of recent results on the dilational surface viscoelastic properties of aqueous solutions of non-ionic polymers is given. In the frequency range from 0.001 up to 1000 Hz the methods of transverse and longitudinal surface waves and the oscillating barrier method were applied. Viscoelastic behavior of adsorbed polymer films significantly differs from the behavior of films formed by only conventional surfactants of low molecular weight. For example, the dynamic surface elasticity of the former systems is low and almost constant in a broad concentration range. One can observe the increase of the surface elasticity only at extremely low concentrations and/or in the range of semi-dilute solutions. If the surface stress relaxation in conventional surfactant solutions is usually determined by the diffusional exchange between the surface layer and the bulk phase, the relaxation processes in the polymer systems proceed mainly inside the surface layer. Possible mechanism of the latter relaxation is discussed.
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Affiliation(s)
- B A Noskov
- Chemical Department, St Petersburg State University, Universitetsky pr 2, 198904 St Petersburg, Russia.
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44
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Rivillon S, Muñoz MG, Monroy F, Ortega F, Rubio RG. Experimental Study of the Dynamic Properties of Monolayers of PS−PEO Block Copolymers: The Attractive Monomer Surface Case. Macromolecules 2003. [DOI: 10.1021/ma021260z] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sandrine Rivillon
- Departamento de Química Física I, Facultad de Química, Universidad Complutense, 28040 Madrid, Spain
| | - Mercedes G. Muñoz
- Departamento de Química Física I, Facultad de Química, Universidad Complutense, 28040 Madrid, Spain
| | - Francisco Monroy
- Departamento de Química Física I, Facultad de Química, Universidad Complutense, 28040 Madrid, Spain
| | - Francisco Ortega
- Departamento de Química Física I, Facultad de Química, Universidad Complutense, 28040 Madrid, Spain
| | - Ramón G. Rubio
- Departamento de Química Física I, Facultad de Química, Universidad Complutense, 28040 Madrid, Spain
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