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Debais G, Missoni LL, Perez Sirkin YA, Tagliazucchi M. Theoretical treatment of complex coacervate core micelles: structure and pH-induced disassembly. SOFT MATTER 2023; 19:7602-7612. [PMID: 37756111 DOI: 10.1039/d3sm01047c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/28/2023]
Abstract
Complex coacervate core micelles (C3Ms) are supramolecular soft nanostructures formed by the assembly of a block copolymer and an oppositely charged homopolymer. The coacervation of the charged segments in both macromolecules drives the formation of the core of the C3M, while the neutral block of the copolymer forms the corona. This work introduces a molecular theory (MOLT) that predicts the internal structure and stimuli-responsive properties of C3Ms and explicitly considers the chemical architecture of the polyelectrolytes, their acid-based equilibria and electrostatic and non-electrostatic interactions. In order to accurately predict complex coacervation, the correlations between charged species are incorporated into MOLT as ion-pairing processes, which are modeled using a coupled chemical equilibrium formalism. Very good agreement was observed between the experimental results in the literature and MOLT predictions for the scaling relationships that relate the dimensions of the micelle (aggregation number and sizes of the micelle and the core) to the lengths of the different blocks. MOLT was used to study the disassembly of the micelles when the solution pH is driven away from the value that guarantees the charge stoichiometry of the core. This study reveals that very sharp disassembly transitions can be obtained by tuning the length or architecture of the copolymer component, thereby suggesting potential routes to design C3Ms capable of releasing their components at very precise pH values.
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Affiliation(s)
- Gabriel Debais
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Inorgánica Analítica y Química Física y CONICET-Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Instituto de Química de los Materiales, Ambiente y Energía (INQUIMAE), Pabellón 2, Ciudad Universitaria, Ciudad Autónoma de Buenos Aires, C1428, Argentina.
| | - Leandro L Missoni
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Inorgánica Analítica y Química Física y CONICET-Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Instituto de Química de los Materiales, Ambiente y Energía (INQUIMAE), Pabellón 2, Ciudad Universitaria, Ciudad Autónoma de Buenos Aires, C1428, Argentina.
| | - Yamila A Perez Sirkin
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Inorgánica Analítica y Química Física y CONICET-Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Instituto de Química de los Materiales, Ambiente y Energía (INQUIMAE), Pabellón 2, Ciudad Universitaria, Ciudad Autónoma de Buenos Aires, C1428, Argentina.
| | - Mario Tagliazucchi
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Inorgánica Analítica y Química Física y CONICET-Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Instituto de Química de los Materiales, Ambiente y Energía (INQUIMAE), Pabellón 2, Ciudad Universitaria, Ciudad Autónoma de Buenos Aires, C1428, Argentina.
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Coria-Oriundo LL, Debais G, Apuzzo E, Herrera SE, Ceolín M, Azzaroni O, Battaglini F, Tagliazucchi M. Phase Behavior and Electrochemical Properties of Highly Asymmetric Redox Coacervates. J Phys Chem B 2023; 127:7636-7647. [PMID: 37639479 DOI: 10.1021/acs.jpcb.3c03680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
This work reports the phase behavior and electrochemical properties of liquid coacervates made of ferricyanide and poly(ethylenimine). In contrast to the typical polyanion/polycation pairs used in liquid coacervates, the ferricyanide/poly(ethylenimine) system is highly asymmetric because poly(ethylenimine) has approximately 170 charges per molecule, while ferricyanide has only 3. Two types of phase diagrams were measured and fitted with a theoretical model. In the first type of diagram, the stability of the coacervate was studied in the plane given by the concentration of poly(ethylenimine) versus the concentration of ferricyanide for a fixed concentration of added monovalent salt (NaCl). The second type of diagram involved the plane given by the concentration of poly(ethylenimine) vs the concentration of the added monovalent salt for a fixed poly(ethyleneimine)/ferricyanide ratio. Interestingly, these phase diagrams displayed qualitative similarities to those of symmetric polyanion/polycation systems, suggesting that coacervates formed by a polyelectrolyte and a small multivalent ion can be treated as a specific case of polyelectrolyte coacervate. The characterization of the electrochemical properties of the coacervate revealed that the addition of monovalent salt greatly enhances charge transport, presumably by breaking ion pairs between ferricyanide and poly(ethylenimine). This finding highlights the significant influence of added salt on the transport properties of coacervates. This study provides the first comprehensive characterization of the phase behavior and transport properties of asymmetric coacervates and places these results within the broader context of the better-known symmetric polyelectrolyte coacervates.
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Affiliation(s)
- Lucy L Coria-Oriundo
- Facultad de Ciencias Exactas y Naturales, Departamento de Química Inorgánica Analítica y Química Física, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, C1428 Ciudad Autónoma de Buenos Aires, Argentina
- Facultad de Ciencias Exactas y Naturales, Instituto de Química de los Materiales, Ambiente y Energía (INQUIMAE), CONICET─Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, C1428 Ciudad Autónoma de Buenos Aires, Argentina
| | - Gabriel Debais
- Facultad de Ciencias Exactas y Naturales, Departamento de Química Inorgánica Analítica y Química Física, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, C1428 Ciudad Autónoma de Buenos Aires, Argentina
- Facultad de Ciencias Exactas y Naturales, Instituto de Química de los Materiales, Ambiente y Energía (INQUIMAE), CONICET─Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, C1428 Ciudad Autónoma de Buenos Aires, Argentina
| | - Eugenia Apuzzo
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA-CONICET), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calle 64 y Diag. 113, 1900 La Plata, Argentina
| | - Santiago E Herrera
- Facultad de Ciencias Exactas y Naturales, Departamento de Química Inorgánica Analítica y Química Física, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, C1428 Ciudad Autónoma de Buenos Aires, Argentina
- Facultad de Ciencias Exactas y Naturales, Instituto de Química de los Materiales, Ambiente y Energía (INQUIMAE), CONICET─Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, C1428 Ciudad Autónoma de Buenos Aires, Argentina
| | - Marcelo Ceolín
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA-CONICET), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calle 64 y Diag. 113, 1900 La Plata, Argentina
| | - Omar Azzaroni
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA-CONICET), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calle 64 y Diag. 113, 1900 La Plata, Argentina
| | - Fernando Battaglini
- Facultad de Ciencias Exactas y Naturales, Departamento de Química Inorgánica Analítica y Química Física, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, C1428 Ciudad Autónoma de Buenos Aires, Argentina
- Facultad de Ciencias Exactas y Naturales, Instituto de Química de los Materiales, Ambiente y Energía (INQUIMAE), CONICET─Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, C1428 Ciudad Autónoma de Buenos Aires, Argentina
| | - Mario Tagliazucchi
- Facultad de Ciencias Exactas y Naturales, Departamento de Química Inorgánica Analítica y Química Física, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, C1428 Ciudad Autónoma de Buenos Aires, Argentina
- Facultad de Ciencias Exactas y Naturales, Instituto de Química de los Materiales, Ambiente y Energía (INQUIMAE), CONICET─Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, C1428 Ciudad Autónoma de Buenos Aires, Argentina
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Debais G, Tagliazucchi M. Two Sides of the Same Coin: A Unified Theoretical Treatment of Polyelectrolyte Complexation in Solution and Layer-by-Layer Films. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c00250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gabriel Debais
- Facultad de Ciencias Exactas y Naturales, Departamento de Química Inorgánica Analítica y Química Física, Universidad de Buenos Aires, C1053ABH Buenos Aires, Argentina
- Facultad de Ciencias Exactas y Naturales, Instituto de Química de los Materiales, Ambiente y Energía (INQUIMAE)CONICET- Universidad de Buenos Aires, C1053ABH Buenos Aires, Argentina
| | - Mario Tagliazucchi
- Facultad de Ciencias Exactas y Naturales, Departamento de Química Inorgánica Analítica y Química Física, Universidad de Buenos Aires, C1053ABH Buenos Aires, Argentina
- Facultad de Ciencias Exactas y Naturales, Instituto de Química de los Materiales, Ambiente y Energía (INQUIMAE)CONICET- Universidad de Buenos Aires, C1053ABH Buenos Aires, Argentina
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Scission energies of surfactant wormlike micelles loaded with nonpolar additives. J Colloid Interface Sci 2021; 604:757-766. [DOI: 10.1016/j.jcis.2021.07.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/30/2021] [Accepted: 07/01/2021] [Indexed: 11/30/2022]
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Tran E, Richmond GL. Interfacial Steric and Molecular Bonding Effects Contributing to the Stability of Neutrally Charged Nanoemulsions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:12643-12653. [PMID: 34662126 DOI: 10.1021/acs.langmuir.1c02020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In cosmetic, pharmaceutical, and food applications, many active ingredients have limited bioavailability in an aqueous environment, and in that context, nanoemulsions provide a mechanism for encapsulation, protection, and transport. These dispersed oil droplets are on the order of 100s of nanometers in diameter and owe their long-term stability to emulsifiers that are commonly charged. More recently, applications have been utilizing nonionic species as stabilizing agents due to their enhanced biosafety. DLVO (named after Derjaguin, Landau, Verwey, and Overbeek) theory has been central in the description of colloid stability, which emphasizes repulsive electrostatic forces, while extended DLVO theory also accounts for steric effects. Past studies of nanoemulsions have largely employed charged surfactants and polyelectrolytes, making it difficult to decouple electrostatic and steric effects as they relate to droplet stability. To better understand steric and molecular factors contributing to the stability of "uncharged" droplets, we have created nanoemulsions with sodium dodecyl sulfate (SDS) and poly(N-vinylacetamide) (PNVA). Though SDS is anionic, with PNVA coating the droplet surfaces, the ζ-potentials of these nanoemulsions are ∼0 mV. Despite minimizing electrostatic contributions, these nanoemulsions are stable for upward of a month with interesting dynamics. By employing dynamic light scattering, vibrational sum frequency scattering spectroscopy, and calculating interaction pair potentials using extended DLVO theory, we learn that the thickness of the PNVA layer plays a critical role in stabilizing these "uncharged" nanoemulsions. Beyond the sterics, the molecular conformation of the PNVA strands also contributes to the droplet stability. The adsorbed PNVA strands are shown to form stratified, rigid polymer networks that prevent the nanoemulsions from rapid destabilization.
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Affiliation(s)
- Emma Tran
- University of Oregon, Eugene, Oregon 97403, United States
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Perez Sirkin YA, Tagliazucchi M, Szleifer I. Nanopore gates via reversible crosslinking of polymer brushes: a theoretical study. SOFT MATTER 2021; 17:2791-2802. [PMID: 33544104 DOI: 10.1039/d0sm01760d] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Polymer-brush-modified nanopores are synthetic structures inspired by the gated transport exhibited by their biological counterparts. This work theoretically analyzes how the reversible crosslinking of a polymer network by soluble species can be used to control transport through nanochannels and pores. The study was performed with a molecular theory that allows inhomogeneities in the three spatial dimensions and explicitly takes into account the size, shape and conformations of all molecular species, considers the intermolecular interactions between the polymers and the soluble crosslinkers and includes the presence of a translocating particle inside the pore. It is shown than increasing the concentration of the soluble crosslinkers in bulk solution leads to a gradual increase of its number within the pore until a critical bulk concentration is reached. At the critical concentration, the number of crosslinkers inside the pore increases abruptly. For long chains, this sudden transition triggers the collapse of the polymer brush to the center of the nanopore. The resulting structure increases the free-energy barrier that a translocating particle has to surmount to go across the pore and modifies the route of translocation from the axis of the pore to its walls. On the other hand, for short polymer chains the crosslinkers trigger the collapse of the brush to the pore walls, which reduces the translocation barrier.
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Affiliation(s)
- Yamila A Perez Sirkin
- INQUIMAE-CONICET and DQIAQF, University of Buenos Aires, School of Sciences, Ciudad Universitaria, Pabellón 2, Ciudad Autónoma de Buenos Aires C1428EHA, Argentina.
| | - Mario Tagliazucchi
- INQUIMAE-CONICET and DQIAQF, University of Buenos Aires, School of Sciences, Ciudad Universitaria, Pabellón 2, Ciudad Autónoma de Buenos Aires C1428EHA, Argentina.
| | - Igal Szleifer
- Department of Biomedical Engineering, Department of Chemistry and Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, USA.
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Debais G, Tagliazucchi M. Microphase separation and aggregate self-assembly in brushes of oppositely charged polyelectrolytes triggered by ion pairing. J Chem Phys 2020; 153:144903. [PMID: 33086835 DOI: 10.1063/5.0020779] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
This work applies a molecular theory to study the formation of lateral self-assembled aggregates in mixed brushes composed of polyanion and polycation chains. In order to overcome the well-known limitations of mean-field electrostatics to capture polyelectrolyte complexation, the formation of ion pairs between anionic and cationic groups in the polyelectrolytes is explicitly modeled in our theory as an association reaction. This feature is essential to capture the microphase separation of the mixed brush and the formation of lateral aggregates triggered by polyelectrolyte complexation. The effects of solution pH and ionic strength, surface coverage, and chain length on the morphology of the mixed brush are systematically explored. It is shown that increasing salt concentration leads to the rupture of polyelectrolyte complexes and the stabilization of the homogeneous, non-aggregated brush, providing that the formation of ion pairs between the polyelectrolytes and the salt ions in solution is explicitly accounted for by the theory. The inclusion of ion-pairing association reactions between oppositely charged polyelectrolytes within a mean-field description of electrostatics emerges from this work as a useful and simple theoretical approach to capture the formation of polyelectrolyte complexes and their responsiveness to solution ionic strength and pH.
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Affiliation(s)
- Gabriel Debais
- Instituto de Química Física de los Materiales, Medio Ambiente y Energía and Departamento de Química Inorgánica Analítica y Química Física, Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Pabellón 2, Ciudad Autónoma de Buenos Aires C1428EHA, Argentina
| | - Mario Tagliazucchi
- Instituto de Química Física de los Materiales, Medio Ambiente y Energía and Departamento de Química Inorgánica Analítica y Química Física, Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Pabellón 2, Ciudad Autónoma de Buenos Aires C1428EHA, Argentina
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Salem SR, Sullivan JL, Topham PD, Tighe BJ. Supramolecular host–guest carrier based on maltose-modified hyperbranched polymer and polyelectrolyte multilayers: toward stable and reusable glucose biosensor. Polym Bull (Berl) 2020. [DOI: 10.1007/s00289-019-02902-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Maldonado L, Debais G, Davia F, Méndez De Leo LP, Tagliazucchi M. Interpolymer complexes of poly(sulfonic acid)s and poly(ethylene oxide): an unexpected association. SOFT MATTER 2019; 15:9318-9324. [PMID: 31681927 DOI: 10.1039/c9sm01768b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The formation of novel interpolymer complexes (IPCs) between poly(sulfonic acid)s and poly(ethylene oxide) (PEO) is reported. The complexes were precipitated from polymer mixtures in aqueous solution and deposited on surfaces as layer-by-layer films. Based on evidence from infrared spectroscopy, the interpolymer association in poly(sulfonic acid)/PEO IPCs is ascribed to hydrogen bonding between the sulfonic acid and the ether in PEO. This interaction is not anticipated because sulfonic acids are fully dissociated in aqueous solutions due to their strong acidity. Theoretical calculations suggest that the unexpected association of PEO and poly(sulfonic acid)s results from the formation of very strong sulfonic-acid/ether hydrogen bonds, which increase the apparent pKas of the poly(sulfonic acid)s and, therefore, decrease the net charge of these polymers. It is shown that while poly(styrene sulfonic acid) (PSSA) and Nafion form IPCs with PEO, poly(vinyl sulfonic acid) (PVSA) does not. This result is explained in terms of the hydrodrophobic nature of PSSA and Nafion, which stabilizes their IPCs, and the fact that hydrogen bonds in PSSA/PEO IPCs are predicted to be stronger than in PVSA/PEO IPCs.
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Affiliation(s)
- Liliana Maldonado
- INQUIMAE-CONICET and DQIAQF, Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Pabellón 2, Ciudad Autónoma de Buenos Aires C1428EHA, Argentina.
| | - Gabriel Debais
- INQUIMAE-CONICET and DQIAQF, Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Pabellón 2, Ciudad Autónoma de Buenos Aires C1428EHA, Argentina.
| | - Federico Davia
- INQUIMAE-CONICET and DQIAQF, Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Pabellón 2, Ciudad Autónoma de Buenos Aires C1428EHA, Argentina.
| | - Lucila P Méndez De Leo
- INQUIMAE-CONICET and DQIAQF, Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Pabellón 2, Ciudad Autónoma de Buenos Aires C1428EHA, Argentina.
| | - Mario Tagliazucchi
- INQUIMAE-CONICET and DQIAQF, Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Pabellón 2, Ciudad Autónoma de Buenos Aires C1428EHA, Argentina.
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Affiliation(s)
- Hadi M. Fares
- Department of Chemistry and
Biochemistry, The Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Joseph B. Schlenoff
- Department of Chemistry and
Biochemistry, The Florida State University, Tallahassee, Florida 32306-4390, United States
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Gleria I, Mocskos E, Tagliazucchi M. Minimum free-energy paths for the self-organization of polymer brushes. SOFT MATTER 2017; 13:2362-2370. [PMID: 28275766 DOI: 10.1039/c6sm02725c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A methodology to calculate minimum free-energy paths based on the combination of a molecular theory and the improved string method is introduced and applied to study the self-organization of polymer brushes under poor solvent conditions. Polymer brushes in a poor solvent cannot undergo macroscopic phase separation due to the physical constraint imposed by the grafting points; therefore, they microphase separate forming aggregates. Under some conditions, the theory predicts that the homogeneous brush and the aggregates can exist as two different minima of the free energy. The theoretical methodology introduced in this work allows us to predict the minimum free-energy path connecting these two minima as well as the morphology of the system along the path. It is shown that the transition between the homogeneous brush and the aggregates may involve a free-energy barrier or be barrierless depending on the relative stability of the two morphologies and the chain length and grafting density of the polymer. In the case where a free-energy barrier exists, one of the morphologies is a metastable structure and, therefore, the properties of the brush as the quality of the solvent is cycled are expected to display hysteresis. The theory is also applied to study the adhesion/deadhesion transition between two opposing surfaces modified by identical polymer brushes and it is shown that this process may also require surpassing a free-energy barrier.
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Affiliation(s)
- Ignacio Gleria
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Computación, Buenos Aires, Argentina
| | - Esteban Mocskos
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Computación, Buenos Aires, Argentina and CONICET, Centro de Simulación Computacional para Aplicaciones Tecnológicas (CSC), Buenos Aires, Argentina
| | - Mario Tagliazucchi
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Inorgánica, Analítica y Química-Física, Buenos Aires, Argentina. and CONICET-Universidad de Buenos Aires, Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE), Buenos Aires, Argentina
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