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Maine A, Encinas MV, Pavez J, Urzúa M, Günther G, Reyes I, Briones X. On the Preparation of Thin Films of Stearyl Methacrylate Directly Photo-polymerized at the Air-Water Interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:11658-11665. [PMID: 36112511 DOI: 10.1021/acs.langmuir.2c01513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Characterization of bidimensional polymeric films at the air-water interface in the Langmuir trough, despite being a recurrent topic, usually refers to films of already formed polymeric materials, with very scarce reports on direct polymerization at the air-water interface. In the present work, we studied the photo-polymerization of stearyl methacrylate directly at the air-water interface under a nitrogen atmosphere, with the radical initiator solubilized in the aqueous phase. Two-dimensional (2D) polymerization was monitored by measuring the pressure-area isotherm at different irradiation times. The polymerization leads to a film with an isotherm different from that observed for the monomer, where the surface pressure is directly related to the irradiation time. The shape of this isotherm confirms the presence of a compressed liquid phase, where a higher order can be attained as a consequence of stronger packing forces involving polymer chains. The presence of inter-chain interactions allows rearrangements on the surface of the subphase, and even before the collapse a dense 2D ordering (with a solid phase-like behavior) can be observed. We present a new one-step, solvent-free procedure to obtain a photo-polymeric film directly at the air-water interface, which can be transferred to a solid surface by the Langmuir-Blodgett method, allowing film preparation of controlled thickness. Films were characterized by measuring properties such as thickness, roughness, and hydrophobicity and comparing them with films obtained from a conventional polymer. We report the differences between the interfacial behavior of amphiphilic molecules and nanomaterials such as films obtained by photo-polymerization, PSMA, directly on the air-water interface.
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Affiliation(s)
- A Maine
- Departamento de Química Orgánica y Fisicoquímica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Dr. Carlos Lorca Tobar 964, Independencia, Región Metropolitana, Casilla 233, Santiago, Chile
- Departamento de Química, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Casilla 653, Santiago, Chile
| | - M V Encinas
- Facultad de Química y Biología, Universidad de Santiago de Chile, Av. B. O'Higgins 3363 Santiago, Chile
| | - J Pavez
- Departamento de Química de los Materiales, Facultad de Química y Biología, Soft Matter Research-Technology Center, SMAT-C, Universidad de Santiago de Chile, Av. B. O'Higgins 3363 Santiago, Chile
| | - M Urzúa
- Departamento de Química, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Casilla 653, Santiago, Chile
| | - G Günther
- Departamento de Química Orgánica y Fisicoquímica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Dr. Carlos Lorca Tobar 964, Independencia, Región Metropolitana, Casilla 233, Santiago, Chile
| | - I Reyes
- Departamento de Química Orgánica y Fisicoquímica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Dr. Carlos Lorca Tobar 964, Independencia, Región Metropolitana, Casilla 233, Santiago, Chile
- Departamento de Química, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Casilla 653, Santiago, Chile
| | - X Briones
- Departamento de Química Orgánica y Fisicoquímica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Dr. Carlos Lorca Tobar 964, Independencia, Región Metropolitana, Casilla 233, Santiago, Chile
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In situ determination of the structure and composition of Langmuir monolayers at the air/water interface by neutron and X-ray reflectivity and ellipsometry. Adv Colloid Interface Sci 2021; 293:102434. [PMID: 34022749 DOI: 10.1016/j.cis.2021.102434] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 04/26/2021] [Accepted: 04/27/2021] [Indexed: 02/07/2023]
Abstract
This review focuses on the description of the structure and composition of a variety of Langmuir monolayers (LMs) deposited at the air/water interface by using ellipsometry, Brewster Angle microscopy and scattering techniques, mainly neutron and X-ray reflectometry. Since the first experiment done by Angels Pockels with a homemade trough in her home kitchen until today, LMs of different materials have been extensively studied providing not only relevant model systems in biology, physics and chemistry but also precursors of novel materials via their deposition on solid substrates. There is a vast amount of surface-active materials that can form LMs and, therefore, far from a revision of the state-of-the-art, we will emphasize here: (i) some fundamental aspects to understand the physics behind the molecular deposition at the air/water interface; (ii) the advantages in using in situ techniques, such as reflectometry or ellipsometry, to resolve the interfacial architecture and conformation of molecular films; and, finally, (iii) a summary of several systems that have certain interest from the experimental or conceptual point of view. Concretely, we will report here advances in polymers confined to interfaces and surfactants, from fatty acids and phospholipids monolayers to more unconventional ones such as graphene oxide.
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da Rocha Rodrigues R, da Silva RLCG, Caseli L, Péres LO. Conjugated polymers as Langmuir and Langmuir-Blodgett films: Challenges and applications in nanostructured devices. Adv Colloid Interface Sci 2020; 285:102277. [PMID: 32992077 DOI: 10.1016/j.cis.2020.102277] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 09/14/2020] [Accepted: 09/20/2020] [Indexed: 12/01/2022]
Abstract
Initially developed for classic systems composed of fatty acids and phospholipids, the Langmuir and Langmuir-Blodgett (LB) techniques allow the fabrication of nanometer-scale devices at self-assembly interfaces with high control over the thickness and molecular architecture. Their application in the research and production of new plastic materials has grown considerably over the past few decades due to the efficiency of conjugated polymers (CPs) for the production of light-emitting diodes, flexible displays, solar cells, and other photoelectronic devices. The structuring of polymers at different interfaces is not trivial as this class of macromolecules can undergo through different processes of folding/unfolding, which hinders the formation of stable Langmuir monolayers and, consequently, the production of Langmuir-Blodgett films. With these ideas in mind, the present article aims to review a series of elements related to the formation of stable Langmuir and Langmuir-Blodgett films of CPs, especially those based on poly(phenylene vinylene)s, polyfluorenes, and polythiophenes. This review is divided into two parts where we first discuss the formation of neat CP films, and then the strategies for the formation of stable CP films based on the co-immobilization with fatty acids, other polymers, and enzymes as mixed films.
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Affiliation(s)
- Rebeca da Rocha Rodrigues
- Laboratory of Hybrid Materials, Department of Chemistry, Federal University of São Paulo, Diadema, São Paulo, Brazil
| | | | - Luciano Caseli
- Laboratory of Hybrid Materials, Department of Chemistry, Federal University of São Paulo, Diadema, São Paulo, Brazil.
| | - Laura Oliveira Péres
- Laboratory of Hybrid Materials, Department of Chemistry, Federal University of São Paulo, Diadema, São Paulo, Brazil
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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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Tarazona NA, Machatschek R, Lendlein A. Unraveling the Interplay between Abiotic Hydrolytic Degradation and Crystallization of Bacterial Polyesters Comprising Short and Medium Side-Chain-Length Polyhydroxyalkanoates. Biomacromolecules 2020; 21:761-771. [PMID: 31841314 DOI: 10.1021/acs.biomac.9b01458] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Polyhydroxyalkanoates (PHAs) have attracted attention as degradable (co)polyesters which can be produced by microorganisms with variations in the side chain. This structural variation influences not only the thermomechanical properties of the material but also its degradation behavior. Here, we used Langmuir monolayers at the air-water (A-W) interface as suitable models for evaluating the abiotic degradation of two PHAs with different side-chain lengths and crystallinity. By controlling the polymer state (semicrystalline, amorphous), the packing density, the pH, and the degradation mechanism, we could draw several significant conclusions. (i) The maximum degree of crystallinity for a PHA film to be efficiently degraded up to pH = 12.3 is 40%. (ii) PHA made of repeating units with shorter side-chain length are more easily hydrolyzed under alkaline conditions. The efficiency of alkaline hydrolysis decreased by about 65% when the polymer was 40% crystalline. (iii) In PHA films with a relatively high initial crystallinity, abiotic degradation initiated a chemi-crystallization phenomenon, detected as an increase in the storage modulus (E'). This could translate into an increase in brittleness and reduction in the material degradability. Finally, we demonstrate the stability of the measurement system for long-term experiments, which allows degradation conditions for polymers that could closely simulate real-time degradation.
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Affiliation(s)
- Natalia A Tarazona
- Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies , Helmholtz-Zentrum Geesthacht , Kantstrasse 55 , 14513 Teltow , Germany
| | - Rainhard Machatschek
- Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies , Helmholtz-Zentrum Geesthacht , Kantstrasse 55 , 14513 Teltow , Germany
| | - Andreas Lendlein
- Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies , Helmholtz-Zentrum Geesthacht , Kantstrasse 55 , 14513 Teltow , Germany.,Institute of Chemistry , University of Potsdam , Karl-Liebknecht-Strasse 24-25 , 14469 Potsdam , Germany
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Tarazona NA, Machatschek R, Schulz B, Prieto MA, Lendlein A. Molecular Insights into the Physical Adsorption of Amphiphilic Protein PhaF onto Copolyester Surfaces. Biomacromolecules 2019; 20:3242-3252. [DOI: 10.1021/acs.biomac.9b00069] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Natalia A. Tarazona
- Institute of Biomaterial
Science and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Kantstraße 55, 14513 Teltow, Germany
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Rainhard Machatschek
- Institute of Biomaterial
Science and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Kantstraße 55, 14513 Teltow, Germany
| | - Burkhard Schulz
- Institute of Biomaterial
Science and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Kantstraße 55, 14513 Teltow, Germany
- Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14469 Potsdam, Germany
| | - M. Auxiliadora Prieto
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Andreas Lendlein
- Institute of Biomaterial
Science and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Kantstraße 55, 14513 Teltow, Germany
- Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14469 Potsdam, Germany
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7
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Sagis LMC, Liu B, Li Y, Essers J, Yang J, Moghimikheirabadi A, Hinderink E, Berton-Carabin C, Schroen K. Dynamic heterogeneity in complex interfaces of soft interface-dominated materials. Sci Rep 2019; 9:2938. [PMID: 30814587 PMCID: PMC6393553 DOI: 10.1038/s41598-019-39761-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 02/01/2019] [Indexed: 11/09/2022] Open
Abstract
Complex interfaces stabilized by proteins, polymers or nanoparticles, have a much richer dynamics than those stabilized by simple surfactants. By subjecting fluid-fluid interfaces to step extension-compression deformations, we show that in general these complex interfaces have dynamic heterogeneity in their relaxation response that is well described by a Kohlrausch-Williams-Watts function, with stretch exponent β between 0.4-0.6 for extension, and 0.6-1.0 for compression. The difference in β between expansion and compression points to an asymmetry in the dynamics. Using atomic force microscopy and simulations we prove that the dynamic heterogeneity is intimately related to interfacial structural heterogeneity and show that the dominant mode for stretched exponential relaxation is momentum transfer between bulk and interface, a mechanism which has so far largely been ignored in experimental surface rheology. We describe how its rate constant can be determined using molecular dynamics simulations. These interfaces clearly behave like disordered viscoelastic solids and need to be described substantially different from the 2d homogeneous viscoelastic fluids typically formed by simple surfactants.
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Affiliation(s)
- Leonard M C Sagis
- Physics and Physical Chemistry of Foods, Wageningen University, Bornse Weilanden 9, 6708 WG, Wageningen, The Netherlands.
- ETH Zurich, Department of Materials, Polymer Physics, Leopold-Ruzicka-Weg 4, 8093, Zurich, Switzerland.
| | - Bingxue Liu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Key Laboratory of Functional Dairy, College of Food Science and Nutritional Engineering, China Agricultural University, 100083, Beijing, China
| | - Yuan Li
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Key Laboratory of Functional Dairy, College of Food Science and Nutritional Engineering, China Agricultural University, 100083, Beijing, China.
| | - Jeffrey Essers
- Physics and Physical Chemistry of Foods, Wageningen University, Bornse Weilanden 9, 6708 WG, Wageningen, The Netherlands
- Food Process Engineering Group, Wageningen University, Wageningen, 6700 AA, The Netherlands
| | - Jack Yang
- Physics and Physical Chemistry of Foods, Wageningen University, Bornse Weilanden 9, 6708 WG, Wageningen, The Netherlands
| | - Ahmad Moghimikheirabadi
- ETH Zurich, Department of Materials, Polymer Physics, Leopold-Ruzicka-Weg 4, 8093, Zurich, Switzerland
| | - Emma Hinderink
- Food Process Engineering Group, Wageningen University, Wageningen, 6700 AA, The Netherlands
| | - Claire Berton-Carabin
- Food Process Engineering Group, Wageningen University, Wageningen, 6700 AA, The Netherlands
| | - Karin Schroen
- Food Process Engineering Group, Wageningen University, Wageningen, 6700 AA, The Netherlands
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8
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Gyurova AY, Halacheva S, Mileva E. Aqueous solutions of random poly(methyl methacrylate-co-acrylic acid): effect of the acrylic acid content. RSC Adv 2017. [DOI: 10.1039/c7ra00180k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
.Effect of acrylic acid (AA) content on the bulk solution and air/water interfacial properties of PMMA–AA.
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Affiliation(s)
- Anna Y. Gyurova
- Rostislaw Kaischew Institute of Physical Chemistry
- Bulgarian Academy of Sciences
- 1113 Sofia
- Bulgaria
| | | | - Elena Mileva
- Rostislaw Kaischew Institute of Physical Chemistry
- Bulgarian Academy of Sciences
- 1113 Sofia
- Bulgaria
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9
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Aggregation behavior of star-shaped fluoropolymers containing polyhedral oligomeric silsesquioxane (POSS) at the air–water interface. Colloid Polym Sci 2016. [DOI: 10.1007/s00396-016-3986-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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10
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Kumar C, Viswanath P. Dilatational rheology studies on a semicrystalline ferroelectric copolymer at the air–water interface. RSC Adv 2016. [DOI: 10.1039/c5ra27184c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Dilatational rheology of Langmuir film of semicrystalline copolymer studied using oscillatory barrier technique show nonlinear behaviour. Evidence for low temperature phase transition, strain hardening and cross over behaviour with frequency is seen.
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Affiliation(s)
- Chandan Kumar
- Center for Nano and Soft Matter Sciences
- Bangalore
- India
| | - P. Viswanath
- Center for Nano and Soft Matter Sciences
- Bangalore
- India
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11
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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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Li Z, Ma X, Zang D, Guan X, Zhu L, Liu J, Chen F. Interfacial rheology and aggregation behaviour of amphiphilic CBABC-type pentablock copolymers at the air–water interface: effects of block ratio and chain length. RSC Adv 2015. [DOI: 10.1039/c5ra08109b] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The interfacial rheology, aggregation behaviour and packing model of the structure evolution of three amphiphilic CBABC-type pentablock copolymers were investigated at the air–water interface.
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Affiliation(s)
- Zhiguang Li
- Key Laboratory of Space Applied Physics and Chemistry
- Ministry of Education
- School of Science
- Northwestern Polytechnical University
- Xi’an 710129
| | - Xiaoyan Ma
- Key Laboratory of Space Applied Physics and Chemistry
- Ministry of Education
- School of Science
- Northwestern Polytechnical University
- Xi’an 710129
| | - Duyang Zang
- Key Laboratory of Space Applied Physics and Chemistry
- Ministry of Education
- School of Science
- Northwestern Polytechnical University
- Xi’an 710129
| | - Xinghua Guan
- Key Laboratory of Space Applied Physics and Chemistry
- Ministry of Education
- School of Science
- Northwestern Polytechnical University
- Xi’an 710129
| | - Lin Zhu
- Key Laboratory of Space Applied Physics and Chemistry
- Ministry of Education
- School of Science
- Northwestern Polytechnical University
- Xi’an 710129
| | - Jinshu Liu
- Key Laboratory of Space Applied Physics and Chemistry
- Ministry of Education
- School of Science
- Northwestern Polytechnical University
- Xi’an 710129
| | - Fang Chen
- Key Laboratory of Space Applied Physics and Chemistry
- Ministry of Education
- School of Science
- Northwestern Polytechnical University
- Xi’an 710129
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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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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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15
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Particle laden fluid interfaces: dynamics and interfacial rheology. Adv Colloid Interface Sci 2014; 206:303-19. [PMID: 24200090 DOI: 10.1016/j.cis.2013.10.010] [Citation(s) in RCA: 122] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 10/09/2013] [Accepted: 10/10/2013] [Indexed: 12/30/2022]
Abstract
We review the dynamics of particle laden interfaces, both particle monolayers and particle+surfactant monolayers. We also discuss the use of the Brownian motion of microparticles trapped at fluid interfaces for measuring the shear rheology of surfactant and polymer monolayers. We describe the basic concepts of interfacial rheology and the different experimental methods for measuring both dilational and shear surface complex moduli over a broad range of frequencies, with emphasis in the micro-rheology methods. In the case of particles trapped at interfaces the calculation of the diffusion coefficient from the Brownian trajectories of the particles is calculated as a function of particle surface concentration. We describe in detail the calculation in the case of subdiffusive particle dynamics. A comprehensive review of dilational and shear rheology of particle monolayers and particle+surfactant monolayers is presented. Finally the advantages and current open problems of the use of the Brownian motion of microparticles for calculating the shear complex modulus of monolayers are described in detail.
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Li Destri G, Miano F, Marletta G. Structure-rheology relationship in weakly amphiphilic block copolymer Langmuir monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:3345-3353. [PMID: 24650052 DOI: 10.1021/la4043777] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The linear viscoelastic behavior in the low-frequency regime at the water/air interface of three different polystyrene-b-poly(methyl methacrylate) (PS-b-PMMA) copolymer monolayers, with block length ratio varying from 66-33 to 50-50 and 25-75 in molecular units, was studied and related to the interfacial behavior, characterized by means of Langmuir isotherms, and their structure, characterized by means of the atomic force microscopy technique. The two monolayers with the highest PMMA amount showed a single phase transition at about 12 mN/m, the viscoelastic behavior changing from a predominantly elastic to a viscoelastic one. This change in the viscoelastic properties was ascribed to the beginning of entanglement among the PMMA coronas of the predominantly circular quasi-2D micelles formed by the two copolymer systems. Conversely, the polymer with the lowest PMMA amount, despite having the same PMMA block length of the PS-PMMA 50-50 block copolymer, was found to behave as a viscoelastic system at any surface pressure value. This characteristic behavior cannot therefore be simply related to the molecular weight difference, but it has been put in connection to the irregular micelle structure observed in this case, consisting of a mixture of spherical and wormlike micelles, and to the different conformation adopted by the PMMA block. By blending this copolymer with an immiscible elastic homopolymer, namely poly(2-vinylpyridine), it was possible to tune the micelle nanostructure, obtaining regular circular quasi-2D micelles, with viscoelastic properties as expected for the PMMA-rich copolymer monolayers. To the best of our knowledge, this study shows for the first time the explicit dependence upon the relative block length and, in turn, upon the nanostructure of the quasi-2D micelles, of the viscoelastic properties of Langmuir monolayers and suggests that molecular weight and intermolecular interactions are not the only parameters governing the polymer conformation and, in turn, the polymer rheology and dynamics in quasi-2D confined systems.
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Affiliation(s)
- Giovanni Li Destri
- Laboratory for Molecular Surfaces and Nanotechnology (LAMSUN), Department of Chemistry, University of Catania and CSGI , V.le A Doria 6, 95125 Catania, Italy
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Kraska M, Gallei M, Stühn B, Rehahn M. Pressure induced structure formation in Langmuir monolayers of amphiphilic metallocene diblock copolymers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:8284-8291. [PMID: 23738871 DOI: 10.1021/la4007636] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We present in situ structural investigations of a metal-containing diblock copolymer on a water surface. Monolayers of poly(vinylferrocene-b-(2-vinylpyridine)) (PVFc-b-P2VP) block copolymers are studied in a wide range of compositions by varying molar masses of P2VP with two different molecular weights of PVFc. We focus on the role of the respective block partners, PVFc and P2VP, when compressing the layer on the water surface. Compression isotherms are presented and interpreted in terms of the classical gaseous, expanded, and condensed phases. We calculate isothermal compressibilities, which reveal a minimum value independent of the molar masses of the respective block partners. We find the isotherms to be dominated by P2VP while PVFc barely contribute to the compression behavior due to its rather compact coil structure. We consider the diblock copolymer monolayers as a two-dimensional model system, which is reflected by two-dimensional scaling behavior in the semi dilute and condensed regime. By X-ray reflectometry (XR), we monitor in situ the monolayer structure change with increasing surface pressure Π and observe the PVFc-b-P2VP separation at high Π.
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Affiliation(s)
- Martin Kraska
- Institute of Condensed Matter Physics, Technische Universität Darmstadt, D-64289 Darmstadt, Germany.
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18
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Llamas S, Mendoza AJ, Guzmán E, Ortega F, Rubio RG. Salt effects on the air/solution interfacial properties of PEO-containing copolymers: equilibrium, adsorption kinetics and surface rheological behavior. J Colloid Interface Sci 2013; 400:49-58. [PMID: 23582902 DOI: 10.1016/j.jcis.2013.03.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 03/05/2013] [Accepted: 03/06/2013] [Indexed: 10/27/2022]
Abstract
Lithium cations are known to form complexes with the oxygen atoms of poly(oxyethylene) chains. The effect of Li(+) on the surface properties of three block-copolymers containing poly(oxyethylene) (PEO) have been studied. Two types of copolymers have been studied, a water soluble one of the pluronic family, PEO-b-PPO-b-PEO, PPO being poly(propyleneoxyde), and two water insoluble ones: PEO-b-PS and PEO-b-PS-b-PEO, PS being polystyrene. In the case of the pluronic the adsorption kinetics, the equilibrium surface tension isotherm and the aqueous/air surface rheology have been measured, while for the two insoluble copolymers only the surface pressure and the surface rheology have been studied. In all the cases two different Li(+) concentrations have been used. As in the absence of lithium ions, the adsorption kinetics of pluronic solutions shows two processes, and becomes faster as [Li(+)] increases. The kinetics is not diffusion controlled. For a given pluronic concentration the equilibrium surface pressure increases with [Li(+)], and the isotherms show two surface phase transitions, though less marked than for [Li(+)]=0. A similar behavior was found for the equilibrium isotherms of PEO-b-PS and PEO-b-PS-b-PEO. The surface elasticity of these two copolymers was found to increase with [Li(+)] over the whole surface concentration and frequency ranges studied. A smaller effect was found in the case of the pluronic solutions. The results of the pluronic solutions were modeled using a recent theory that takes into account that the molecules can be adsorbed at the surface in two different states. The theory gives a good fit for the adsorption kinetics and a reasonably good prediction of the equilibrium isotherms for low and intermediate concentrations of pluronic. However, the theory is not able to reproduce the isotherm for [Li(+)]=0. Only a semi-quantitative prediction of the surface elasticity is obtained for [pluronic]≤1×10(-3) mM.
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Affiliation(s)
- Sara Llamas
- Departamento de Química Física I, Facultad de Química, Universidad Complutense de Madrid, 28040 Madrid, Spain
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Maestro A, Kotsmar C, Javadi A, Miller R, Ortega F, Rubio RG. Adsorption of β-Casein–Surfactant Mixed Layers at the Air–Water Interface Evaluated by Interfacial Rheology. J Phys Chem B 2012; 116:4898-907. [DOI: 10.1021/jp301031y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Armando Maestro
- Departamento de Química
Física I, Universidad Complutense de Madrid, Ciudad Universitaria s/n, 28040-Madrid, Spain
| | - Csaba Kotsmar
- Department of Chemical and Biomolecular
Engineering, University of California at Berkeley, Berkeley, California, United States
- Max-Planck Institute of Colloids and Interfaces, Potsdam-Golm, Germany
| | - Aliyar Javadi
- Max-Planck Institute of Colloids and Interfaces, Potsdam-Golm, Germany
| | - Reinhard Miller
- Max-Planck Institute of Colloids and Interfaces, Potsdam-Golm, Germany
| | - Francisco Ortega
- Departamento de Química
Física I, Universidad Complutense de Madrid, Ciudad Universitaria s/n, 28040-Madrid, Spain
| | - Ramón G. Rubio
- Departamento de Química
Física I, Universidad Complutense de Madrid, Ciudad Universitaria s/n, 28040-Madrid, Spain
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Maestro A, Guzmán E, Chuliá R, Ortega F, Rubio RG, Miller R. Fluid to soft-glass transition in a quasi-2D system: thermodynamic and rheological evidences for a Langmuir monolayer. Phys Chem Chem Phys 2011; 13:9534-9. [PMID: 21483985 DOI: 10.1039/c1cp20305c] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report an experimental study that points out the existence of a fluid to soft-glass transition in Langmuir polymer monolayers of poly(methyl methacrylate) (PMMA), for which the water/air interface behaves as a poor-solvent. The temperature dependence of surface pressure vs. surface area equilibrium isotherms shows a glass-like transition temperature at T(g,2D)≈ 298 K, significantly lower than the value for bulk PMMA (T(g,bulk)≈ 378 K). The plot of the film thickness h vs. temperature shows a sharp change of slope at about the same temperature, 298 K, which is a typical hallmark of a glass transition in thin polymer films [J. L. Keddie, R. A. L. Jones, R. A. Cory, Europhys. Lett., 1996, 27, 59-64]. Furthermore, slightly above T(g,2D), the temperature dependence of the dilational viscosity does not follow an Arrhenius law, but instead can be described by a Vogel-Fulcher-Tamman equation with parameters that are typical of a fragile glass. Not only the qualitative behavior of three distinct equilibrium and dynamic properties, but also the quantitative agreement of the values of T(g) obtained, are a strong evidence of the existence of a fluid to soft-glass transition in this quasi-2D system.
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Affiliation(s)
- Armando Maestro
- Departamento de Química Física I, Facultad de Química, Universidad Complutense, 28040-Madrid, Spain.
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