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Leclercq L, Modena E, Vert M. Adsorption of proteins at physiological concentrations on pegylated surfaces and the compatibilizing role of adsorbed albumin with respect to other proteins according to optical waveguide lightmode spectroscopy (OWLS). JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2013; 24:1499-518. [DOI: 10.1080/09205063.2013.772045] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Laurent Leclercq
- a Faculty of Pharmacy, Max Mousseron Institute of Biomolecules , UMR CNRS 5247, University Montpellier 1, Team CRBA, 15 Avenue Charles Flahault, BP 14491, 34093, Montpellier Cedex 5 , France
| | - Enrico Modena
- a Faculty of Pharmacy, Max Mousseron Institute of Biomolecules , UMR CNRS 5247, University Montpellier 1, Team CRBA, 15 Avenue Charles Flahault, BP 14491, 34093, Montpellier Cedex 5 , France
| | - Michel Vert
- a Faculty of Pharmacy, Max Mousseron Institute of Biomolecules , UMR CNRS 5247, University Montpellier 1, Team CRBA, 15 Avenue Charles Flahault, BP 14491, 34093, Montpellier Cedex 5 , France
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2
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Price EW, Harirchian-Saei S, Moffitt MG. Strands, networks, and continents from polystyrene dewetting at the air-water interface: implications for amphiphilic block copolymer self-assembly. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:1364-1372. [PMID: 21190349 DOI: 10.1021/la1040618] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We demonstrate that nanoscale aggregates similar to those formed via amphiphilic block copolymer self-assembly at the air-water interface, including strands, networks, and continents, can be generated by the simple spreading of PS homopolymer solutions on water. Two different PS homopolymers of different molecular weight (PS-405k, M(n) = 405 000 g mol(-1) and PS-33k, M(n) = 33 000 g mol(-1)) are spread at the air-water interface at various spreading concentrations ranging from 0.25 to 3.0 mg/mL. Aggregate formation is driven by PS dewetting from water as the spreading solvent evaporates. We propose that a high spreading concentration or a high molecular weight lead to chain entanglements that restrict macromolecular mobility in the solution, enabling the kinetic trapping of nanostructures associated with early and intermediate stages of PS dewetting. Comparison of PS-405k with a mainly hydrophobic PS-b-PEO block copolymer of similar molecular weight (PSEO-392k, M(n) = 392 000 g mol(-1), 2.0 wt % PEO) allows the effect of a relatively short surface active block on aggregate formation to be investigated. We show that whereas the PEO block is not a required component for the formation of strands and other nonglobular aggregates, it does increase the number of these aggregates at a given spreading concentration and decreases the minimum spreading concentration at which these aggregates are observed, along with decreasing the dimensions and polydispersity of specific surface features. The results provide supporting evidence for the role of PS dewetting in the generation of multiple PS-b-PEO aggregate morphologies at the air-water interface, as originally described in earlier paper from our group.
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Affiliation(s)
- Eric W Price
- Department of Chemistry, University of Victoria, Victoria, BC, Canada
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3
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Chang YW, Silas JA, Ugaz VM. A direct probe of the interplay between bilayer morphology and surface reactivity in polymersomes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:12132-12139. [PMID: 20578755 DOI: 10.1021/la1016438] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Bilayer vesicles self-assembled from amphiphilic poly(ethylene oxide)-b-polybutadiene (PEO-b-PBd) copolymers are cell-like structures whose high stability and tunable membrane properties make them ideal for use as potential drug carriers and cell mimicry templates. Understanding how the surface interactions (reaction, binding, etc.) are governed by the bilayer structure is critical to enable construction of polymersomes with tailored colloidal behavior. Here, we adapt a previously established chemical labeling method by incorporating coumarin functionalized copolymer into the vesicular structure. This allows us to probe the effect of poly(ethylene glycol) (PEG) brush and surface architecture on the bimolecular quenching reaction occurring at the polymersome surface. Using these measurements, we have tracked quenching in free solution, on bare particles, and on two types of vesicle surfaces: one where the functionalized copolymer groups are longer than the surrounding unfunctionalized copolymer, and one where both functionalized and unfunctionalized groups are the same length. We find that quenching in the presence of the PEG brush proceeds at less than half the free solution rate in both vesicle architectures. However, the quenching rate is further reduced when the functionalized and unfunctionalized groups are the same length. The surface reaction appears to be dominated by quencher diffusion, a conclusion supported by conductivity measurements and ion partition studies indicating that these effects arise as a consequence of retarded ion mobility in the presence of the PEG brush rather than ion exclusion effects. These studies reveal the interplay between the vesicle bilayer architecture (copolymer composition, chain length, local concentration surrounding the active site) and the surface reaction rate, thereby providing useful insights that can help guide the design of polymersomes with desired functional properties.
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Affiliation(s)
- Ya-Wen Chang
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, USA
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4
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Harirchian-Saei S, Wang MCP, Gates BD, Moffitt MG. Patterning block copolymer aggregates via Langmuir-Blodgett transfer to microcontact-printed substrates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:5998-6008. [PMID: 20334416 DOI: 10.1021/la904561b] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We demonstrate a new strategy for producing hierarchical polymer nanostructures, which combines nanoscale self-assembly of amphiphilic block copolymers at the air-water interface with microscale templated assembly of the resulting aggregates on chemically patterned substrates. Aggregates are formed via interfacial self-assembly of 141k polystyrene-b-poly(ethylene oxide) (PS-b-PEO, MW = 141k, 11.4 wt % PEO) or a blend of 185k PS-b-PEO (MW = 185k, 18.9 wt % PEO) and PS-coated CdS nanoparticles to form strandlike copolymer or copolymer-nanoparticle aggregates. Using Langmuir-Blodgett (LB) techniques, the aggregates are then transferred to patterned substrates possessing alternating hydrophilic/hydrophobic stripes, obtained by microcontact printing octadecyltrichlorosilane (OTS) on glass. The aggregates are transferred under various conditions of surface pressure, orientation of the patterned substrate, and withdrawal speed. Templated assembly of aggregates into the hydrophilic substrate domains is achieved when the hydrophilic/hydrophobic stripes are oriented perpendicular to the water surface during LB transfer; this is explained by surface energy heterogeneities along the subphase-substrate contact line, which induce selective dewetting and concomitant monolayer rearrangement at the drying front. In contrast, parallel orientation of stripes results in nonselective transfer of the monolayer without registration to the underlying surface pattern. By studying the effect of surface pressure, we show that packing constraints imposed by compression of aggregates to high surface densities prevent the formation of patterned LB films that match the established periodicity of the OTS-patterned glass. As well, it is shown that efficient transfer of aggregates to the patterned glass requires slower substrate withdrawal speeds compared to transfer to unpatterned hydrophilic glass.
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Affiliation(s)
- Saman Harirchian-Saei
- Department of Chemistry, University of Victoria, P.O. Box 3065, Victoria, BC, V8W 3V6 Canada
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5
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Rother M, Barqawi H, Pfefferkorn D, Kressler J, Binder WH. Synthesis and Organization of Three-Arm-Star PIB-PEO Block Copolymers at the Air/Water Interface: Langmuir- and Langmuir-Blodgett Film Investigations. MACROMOL CHEM PHYS 2009. [DOI: 10.1002/macp.200900435] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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6
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Xie D, Rezende CA, Liu G, Pispas S, Zhang G, Lee LT. Effect of Hydrogen-Bonding Complexation on the Interfacial Behavior of Poly(isoprene)−b-Poly(ethylene oxide) and Poly(isoprene)−b-Poly(acrylic acid) Langmuir Monolayers. J Phys Chem B 2008; 113:739-44. [DOI: 10.1021/jp808821s] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dinghai Xie
- The Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China, Laboratoire Léon Brillouin, UMR12, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France, and Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635 Athens, Greece
| | - Camila A. Rezende
- The Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China, Laboratoire Léon Brillouin, UMR12, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France, and Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635 Athens, Greece
| | - Guangming Liu
- The Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China, Laboratoire Léon Brillouin, UMR12, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France, and Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635 Athens, Greece
| | - Stergios Pispas
- The Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China, Laboratoire Léon Brillouin, UMR12, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France, and Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635 Athens, Greece
| | - Guangzhao Zhang
- The Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China, Laboratoire Léon Brillouin, UMR12, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France, and Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635 Athens, Greece
| | - Lay-Theng Lee
- The Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China, Laboratoire Léon Brillouin, UMR12, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France, and Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635 Athens, Greece
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7
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Cavallo A, Müller M, Binder K. Monte Carlo Simulation of a Homopolymer−Copolymer Mixture Interacting with a Surface: Bulk versus Surface Micelles and Brush Formation. Macromolecules 2008. [DOI: 10.1021/ma800262f] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- A. Cavallo
- Institut für Physik, Johannes-Gutenberg-Universität, Staudingerweg 7, D-55099 Mainz, Germany, Institut Charles Sadron, 23, rue du Loess, F-67034 Strasbourg, France, and Institut für Theoretische Physik, Friedrich-Hund-Platz 1, Georg-August-Universität, D-37077 Göttingen, Germany
| | - M. Müller
- Institut für Physik, Johannes-Gutenberg-Universität, Staudingerweg 7, D-55099 Mainz, Germany, Institut Charles Sadron, 23, rue du Loess, F-67034 Strasbourg, France, and Institut für Theoretische Physik, Friedrich-Hund-Platz 1, Georg-August-Universität, D-37077 Göttingen, Germany
| | - K. Binder
- Institut für Physik, Johannes-Gutenberg-Universität, Staudingerweg 7, D-55099 Mainz, Germany, Institut Charles Sadron, 23, rue du Loess, F-67034 Strasbourg, France, and Institut für Theoretische Physik, Friedrich-Hund-Platz 1, Georg-August-Universität, D-37077 Göttingen, Germany
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Deschênes L, Bousmina M, Ritcey AM. Micellization of PEO/PS block copolymers at the air/water interface: a simple model for predicting the size and aggregation number of circular surface micelles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:3699-3708. [PMID: 18321139 DOI: 10.1021/la702141h] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Isotherms of monolayers of poly(ethylene oxide) (PEO) and polystyrene (PS) triblock copolymers spread at the air/water interface were obtained by film balance technique. In a low concentration regime, the PEO segments surrounding the PS cores behave the same way as in monolayers of PEO homopolymers. Langmuir-Blodgett (LB) films prepared by transferring the monolayers onto mica at various surface pressures were analyzed by atomic force microscopy (AFM). The results reveal that these block copolymers form micelles at the air/water interface. Within the micelles, the PS blocks act as anchoring structures at the interface. In several cases, aggregation patterns were modified by the dewetting processes that occur in Langmuir-Blodgett films transferred to solid substrates. High transfer surface pressures and metastable states favored these changes in morphology. A flowerlike surface micelle model is proposed to explain the organization of the surface circular micelles. The model can be generalized and applied to diblock copolymers as well. The model permits prediction of the aggregation number and the size of circular surface micelles formed by PEO/PS block copolymers at the air/water interface.
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Affiliation(s)
- Louise Deschênes
- Food Research and Development Centre, Agriculture and Agri-Food Canada, St-Hyacinthe, Québec, Canada.
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9
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Mixed micellar nanoparticle of amphotericin B and poly styrene-block-poly ethylene oxide reduces nephrotoxicity but retains antifungal activity. Arch Pharm Res 2007; 30:1344-9. [PMID: 18038914 DOI: 10.1007/bf02980276] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Mixed micellar nanoparticle consisting of amphotericin B (AmB) and poly styrene-block-poly ethylene oxide (PS-block-PEO) was prepared by high pressure homogenizer. Nephrotoxicity of the nanoparticle was investigated along with antifungal activity and self-aggregation status of the drug in the nanoparticle. Nephrotoxicity was markedly reduced when AmB was intravenously administered to rats as mixed micellar nanoparticle with PS-block-PEO in terms of transmission electron microscopy of tubular cells and creatinine clearance. Antifungal activity of AmB was not altered when the drug was in the form of mixed micellar nanoparticle compared to both conventional formulation and AmB micelle treated by same procedure without PS-block-PEO. Self-aggregation status of AmB molecules revealed monomeric in the mixed micellar nanoparticle with PS-block-PEO up to the therapeutic level of the drug (1-3 mM). The reduced nephrotoxicity of AmB in mixed micellar nanoparticle may be associated with the existence of the drug as monomeric form in the nanoparticle. Based on our result, formulation of AmB as mixed micellar nanoparticle with PS-block-PEO may be a promising alternative for the treatment of fungal diseases in patients who are at risk of renal dysfunction.
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10
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Penfold J. Surface-induced structures in surfactant and polymer–surfactant systems: the potential for interesting surface dynamics. JOURNAL OF NEUTRON RESEARCH 2006. [DOI: 10.1080/10238160600974393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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11
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Peetla C, Graf K, Kressler J. Langmuir monolayer and Langmuir–Blodgett films of amphiphilic triblock copolymers with water-soluble middle block. Colloid Polym Sci 2006. [DOI: 10.1007/s00396-006-1527-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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12
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Zhang J, Cao H, Wan X, Zhou Q. Molecular reorganization of rod-coil diblock copolymers at the air-water interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:6587-92. [PMID: 16831001 DOI: 10.1021/la060844h] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Amphiphilic rod-coil diblock copolymers consisting of flexible poly(ethylene oxide) (PEO) and rodlike poly{(+)-2,5-bis[4'-((S)-2-methylbutoxy)phenyl]styrene} (PMBPS) with predominant hydrophobic contents formed ordered monolayers at the air-water interface. The structures of monolayers transferred to a mica substrate at different surface pressures by the Langmuir-Blodgett method were investigated by atom force microscopy (AFM). For PEO(104)-b-PMBPS(17) copolymer (the subscripts denote the number-averaged polymerization degree of each block), a complete spectrum of molecular reorganization at variable surface pressures was observed. Spherical surface aggregates of LB monolayers were spontaneously formed during the solvent evaporation after the deposition of polymer solution. Continuous compression led to the pancake-to-brush conformation transition of the copolymer that PEO chains desorbed from the air-water interface and went into the water subphase. The effective content of the rod block changed continuously from 61% at zero pressure to 93% at the start of the monolayer collapse, igniting the molecular reorganization. As a result, coalescence of individual spherical aggregates into long cylindrical aggregates with an increase of the surface pressure was observed. For a series of block copolymers PEO(104)-b-PMBPS(m)() (m = 17, 30, 45, 53), as the rod contents increased from 61% to 83%, the morphological transition from spherical aggregates to long cylindrical aggregates in orientational order developed at zero pressure, which showed a similar dependence on the effective contents of the rod block to PEO(104)-b-PMBPS(17) at different pressures. In comparison to coil-coil block copolymers PEO-b-PS, the rod-coil block copolymers PEO-b-PMBPS exhibited distinct structure reorganization behavior, in which the orientation of rod block might play an important role.
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Affiliation(s)
- Jie Zhang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics, Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
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13
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Zhang Q, Gupta S, Emrick T, Russell TP. Surface-functionalized CdSe nanorods for assembly in diblock copolymer templates. J Am Chem Soc 2006; 128:3898-9. [PMID: 16551083 DOI: 10.1021/ja058615p] [Citation(s) in RCA: 176] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Poly(ethylene oxide)-covered CdSe nanorods were prepared and assembled in diblock copolymer templates by floating the block copolymer templates onto aqueous nanorod solutions. The assembly was enabled by consideration of the surface ligand coverage of the nanorods. Alkane-covered CdSe nanorods prepared by state-of-the-art techniques are not compatible with this assembly process. However, poly(ethylene oxide) (PEO)-functionalized CdSe nanorods were successfully used to assemble the nanorods into the channels and pores of diblock copolymer templates. Other water-dispersible CdSe nanorods, such as those covered with 11-mercaptoundecanoic acid (MUA), did not give the desired assemblies. These results are understood by considering the surface energies of the PEO-covered CdSe nanorods in this interfacial assembly process.
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Affiliation(s)
- Qingling Zhang
- Polymer Science & Engineering Department, University of Massachusetts, 120 Governors Drive, Amherst, Massachusetts 01003, USA
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14
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Cheng H, Olvera de la Cruz M. Hydrophobic-Charged Block Copolymer Micelles Induced by Oppositely Charged Surfaces: Salt and pH Dependence. Macromolecules 2006. [DOI: 10.1021/ma051965b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hao Cheng
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208
| | - Monica Olvera de la Cruz
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208
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15
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Kim Y, Pyun J, Fréchet JMJ, Hawker CJ, Frank CW. The dramatic effect of architecture on the self-assembly of block copolymers at interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:10444-58. [PMID: 16262305 DOI: 10.1021/la047122f] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Dramatic morphological changes are observed in the Langmuir-Blodgett (LB) film assemblies of poly(ethylene glycol)-b-(styrene-r-benzocyclobutene) block copolymer (PEG-b-(S-r-BCB)) after intramolecular cross-linking of the S-r-BCB block to form a linear-nanoparticle structure. To isolate architectural effects and allow direct comparison, the linear block copolymer precursor and the linear-nanoparticle block copolymer resulting from selective intramolecular cross-linking of the BCB units were designed to have exactly the same molecular weight and chemical composition but different architecture. It was found that the effect of architecture is pronounced with these macromolecular isomers, which self-assemble into dramatically different surface aggregates. The linear block copolymer forms disklike surface assemblies over the range of compression states, while the linear-nanoparticle block copolymer exhibits long (>10 microm) wormlike aggregates whose length increases as a function of increasing cross-linking density. It is shown that the driving force behind the morphological change is a combination of the altered molecular geometry and the restricted degree of stretching of the nanoparticle block because of the intramolecular cross-linking. A modified approach to interpret the pi-A isotherm, which includes presence of the block copolymer aggregates, is also presented, while the surface rheological properties of the block copolymers at the air-water interface provide in-situ evidence of the aggregates' presence at the air-water interface.
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Affiliation(s)
- Yoojin Kim
- Department of Chemical Engineering, Stanford University, California 94305-5025, USA
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16
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Nyrkova IA, Semenov AN. Multimerization: closed or open association scenario? THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2005; 17:327-37. [PMID: 15973468 DOI: 10.1140/epje/i2004-10146-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2004] [Accepted: 04/20/2005] [Indexed: 05/03/2023]
Abstract
We address the problem of classification of the type of association (multimerization) in solutions of identical unimers. Although the aggregation is still routinely characterized in terms of either "open association" or "closed association" models, neither of the two models can provide a fair description of many aggregation processes. We demonstrate that a realistic multimerization may show mixed basic features, i.e. simultaneously those typical of the classical open association and those typical of the classical closed association. In particular, we show that a living polymerization may seem to exhibit a critical micelle concentration (CMC), whereas the basic integral characteristics of a "closed" system with rather monodisperse micelles ((m(w)/m(n)(mic) = 1.02) may not imply a well-defined CMC. Therefore, a multimerization must be characterized by the detailed micelle size distribution that largely defines the equilibrium and dynamical properties of the system. To this end, we suggest a simple method of deriving the micelle size distribution c(m) (depending also on the total concentration of amphiphilic molecules) from the concentration dependence of just the mean aggregation number, m(w)(c). Our results thus invite a reconsideration of the basic methods used for interpretation of experimental data on micellization.
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Affiliation(s)
- I A Nyrkova
- Physics Department, Moscow State University, Russia
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17
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Cheyne RB, Moffitt MG. Novel two-dimensional "ring and chain" morphologies in Langmuir-Blodgett monolayers of PS-b-PEO block copolymers: effect of spreading solution concentration on self-assembly at the air-water interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:5453-60. [PMID: 15924475 DOI: 10.1021/la0503707] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
A polystyrene-b-poly(ethylene oxide) (PS-b-PEO) (MW = 141k, 11.4 wt% PEO) diblock copolymer in the hydrophobic regime was spread from chloroform solutions of various concentrations at the air-water interface, and the resultant monolayers were transferred to glass substrates and imaged using atomic force microscopy. Monolayers prepared under identical conditions were also characterized at the air-water interface via Langmuir compression isotherms. The effects of spreading solution concentration on surface features, compressibility, and limiting mean molecular area were determined, revealing several interesting trends that have not been reported for other systems of PS-b-PEO. Spreading solutions > or = 0.50 mg/mL resulted almost exclusively in dot and spaghetti morphologies, with no observed continent features, which have been commonly found in more hydrophobic systems. For lower spreading solutions, < or = 0.25 mg/mL, we observed a large predominance of two novel surface morphologies, nanoscale rings and chains. The surface pressure (pi)-area (A) isotherms also exhibited a unique dependence on the spreading solution concentration, with limiting mean molecular areas and isothermal compressibilities of PS-b-PEO monolayers increasing below a critical concentration of spreading solution, suggesting a greater contribution from the PEO blocks. These results suggest that PS chain entanglement prior to solvent evaporation plays an important kinetic role in the extent of PEO adsorption at the air-water interface and in the morphologies of the resulting self-assembled surface aggregates.
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Affiliation(s)
- Robert B Cheyne
- Department of Chemistry, University of Victoria, P.O. Box 3065, Victoria, BC V8W 3V6 Canada
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18
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Zarbakhsh A, Querol A, Bowers J, Webster JRP. Structural studies of amphiphiles adsorbed at liquid-liquid interfaces using neutron reflectometry. Faraday Discuss 2005; 129:155-67; discussion 179-92. [PMID: 15715305 DOI: 10.1039/b404732j] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report the application and refinement of a recently developed method for structural studies at a liquid liquid interface using neutron reflectometry. The technique involves the entrapment of a thin oil layer between a silicon substrate and an aqueous subphase. The thin oil film is prepared by spin-coating an oil film on to an oleophilically treated silicon substrate. During the reflectivity measurement the sample is maintained in a horizontal position, and the angle of incidence of the neutron beam is varied using a supermirror. Attenuation of neutron reflectivity at the lowest angle of incidence is used to determine the oil-layer thickness. We report information regarding the structure at the interface between hexadecane and a 0.1% w/v aqueous solution of the triblock copolymer Pluronic L64 with EO13PO30EO13 (EO = ethylene oxide; PO = propylene oxide) and the interface between hexadecane and a 3.7 mmol dm(-3) (approximately critical micelle concentration) aqueous solution of the cationic surfactant tetradecyltrimethylammonium bromide (C14TAB). For the C14TAB system, the reflectivity data unambiguously reveal the presence of a region highly concentrated in C14TAB on the oil side of the interface. For the Pluronic L64 system, the data suggest that the polymer adsorbs at the interface occupying both oil and water sides of the interface. Model scattering length density profiles that capture these features are presented and further models that better fit the data are discussed.
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Affiliation(s)
- Ali Zarbakhsh
- Centre for Materials Research (Chemistry Department), Queen Mary, University of London, London, UK.
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19
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Mouri E, Matsumoto K, Matsuoka H, Torikai N. Nanostructure of a "carpet"-like dense layer/polyelectrolyte brush layer in a block copolymer monolayer at the air-water interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:1840-1847. [PMID: 15723480 DOI: 10.1021/la040028e] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The "carpet"/brush double layer structure in the polyelectrolyte layer in the amphiphilic diblock copolymer monolayer at the air-water interface was quantitatively studied by in situ neutron reflectometry in addition to X-ray reflectivity measurements. As a result of the higher contrast between polyelectrolyte [poly(methacrylic acid)] and solvent (D(2)O) for the neutron, the brush structure could be estimated more accurately as a function of surface pressure, that is, brush density. The thickness of the carpet layer, which is thought to be formed to reduce the interfacial free energy between water and the hydrophobic layer, was almost constant at 10-20 A at any surface pressure studied. Growth was clearly observed in the whole brush length with increasing surface pressure, and it was estimated to be almost 60% of the full-stretch length of the ionic polymer chain. Furthermore, by the comparison of density profiles by neutron and X-ray reflectometry, an anomalous hydration was suggested.
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Affiliation(s)
- Emiko Mouri
- Department of Polymer Chemistry, Kyoto University, Kyoto 615-8510, Japan
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Peleshanko S, Gunawidjaja R, Jeong J, Shevchenko VV, Tsukruk VV. Surface behavior of amphiphilic heteroarm star-block copolymers with asymmetric architecture. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:9423-9427. [PMID: 15491169 DOI: 10.1021/la049269c] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We study the surface behavior of the asymmetric amphiphilic heteroarm poly(ethylene oxide) (PEO)/polystyrene (PS) star polymer on solid substrate. These star polymers differ in both architecture (four- and three-arm molecules, PEO-b-PS(3) and PEO-b-PS(2)) and in the length of PS chains (molecular weight from about 10 000 up to 24 000). We observed that, for a given chemical composition with a predominant content of hydrophobic blocks, the compression behavior of the PS domain structure controls the surface behavior and the final morphology of the monolayers. New features of the surface behavior of star-block copolymers are high stretching of the PS arms from the interface and enhanced stability of the circular PS domain structure, even at high compression. We suggest that for asymmetric star-block copolymers both architecture and chemical composition heavily favor the formation of highly curved interfaces and, thus, more stable circular domain structure with stretched PS arms.
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Mouri E, Furuya Y, Matsumoto K, Matsuoka H. Hydrophilic chain length dependence of the ionic amphiphilic polymer monolayer structure at the air/water interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:8062-8067. [PMID: 15350073 DOI: 10.1021/la049256z] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Detailed analysis of an interesting poly(methacrylic acid) (PMAA) brush structure in water of a diblock copolymer [(Et(2)SB(m)-b-(MMA)(n), where Et(2)SB is diethylsilacyclobutane] monolayer reported previously was performed by X-ray and neutron reflectometry and indicated that the hydrophilic layer formed with a relatively long PMAA chain is not a simple layer but is divided into two layers, that is, a "carpet"-like dense PMAA layer near the hydrophobic layer and a polyelectrolyte brush layer. The hydrophilic chain length dependence of the diblock copolymer monolayer was analyzed using m:n = 30:x polymer samples, especially of the PMAA double layer structure. With the increase in PMAA chain length in polymer samples, a carpet layer is mainly formed up to n approximately 50. With further increase in the PMAA chain length beyond n approximately 50, a well-defined brush layer appears. On the other hand, the variation in hydrophobic layer thickness with methacrylic acid unit is minimum at the critical PMAA length, that is, n approximately 50 under a constant surface pressure condition. It is strongly suggested that the two discrete layers contribute differently to surface pressure. Furthermore, from the comprehensive viewpoint, the major factor for brush formation was clarified not to be the absolute length of the PMAA chain, but the ratio of PEt(2)SB and PMAA chain length is an important factor.
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Affiliation(s)
- Emiko Mouri
- Department of Polymer Chemistry, Kyoto University, Kyoto 615-8510, Japan
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Peleshanko S, Jeong J, Gunawidjaja R, Tsukruk VV. Amphiphilic Heteroarm PEO-b-PSm Star Polymers at the Air−Water Interface: Aggregation and Surface Morphology. Macromolecules 2004. [DOI: 10.1021/ma0493170] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- S. Peleshanko
- Department of Materials Science and Engineering, Iowa State University, Ames, Iowa 50011
| | - J. Jeong
- Department of Materials Science and Engineering, Iowa State University, Ames, Iowa 50011
| | - R. Gunawidjaja
- Department of Materials Science and Engineering, Iowa State University, Ames, Iowa 50011
| | - V. V. Tsukruk
- Department of Materials Science and Engineering, Iowa State University, Ames, Iowa 50011
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Penfold J, Sivia DS, Staples E, Tucker I, Thomas RK. Surface ordering in dilute dihexadecyl dimethyl ammonium bromide solutions at the air-water interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:2265-2269. [PMID: 15835681 DOI: 10.1021/la035432c] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
At elevated temperatures and in dilute solution, we have observed lamellar surface ordering at the air-water interface of dihexadecyl dimethylammonium bromide, DHDAB, in the presence of electrolyte. With increasing temperature, the onset in ordering is observed between 35 and 40 degrees C. At 40 degrees C, there is an abrupt change in the lamellar spacing, from approximately 33 to approximately 40 A. Furthermore, in the presence of the cosurfactant benzyl alcohol, the ordering occurs at a lower temperature, between 20 and 25 degrees C. The change in lamellar spacing with temperature is attributed to a surface-induced transition, similar to the Lbeta to Lalpha phase transition observed in bulk lamellar dispersions.
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Affiliation(s)
- J Penfold
- ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, OXON, United Kingdom
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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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Lu Y, Hu Y, Wang ZM, Manias E, Chung TC. Synthesis of new amphiphilic diblock copolymers containing poly(ethylene oxide) and poly(?-olefin). ACTA ACUST UNITED AC 2002. [DOI: 10.1002/pola.10427] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Devereaux CA, Baker SM. Surface Features in Langmuir−Blodgett Monolayers of Predominantly Hydrophobic Poly(styrene)−Poly(ethylene oxide) Diblock Copolymer. Macromolecules 2002. [DOI: 10.1021/ma011319m] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- C. A. Devereaux
- Department of Chemistry, Harvey Mudd College, Claremont, California 91711
| | - S. M. Baker
- Department of Chemistry, Harvey Mudd College, Claremont, California 91711
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Brown GJ, Richards RW, Heenan RK. Organisation and interactions in aqueous dispersions of polystyrene–polyethylene oxide block copolymer micelles. POLYMER 2001. [DOI: 10.1016/s0032-3861(01)00252-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Alexander M, Richards RW. Capillary Wave Phenomena at the Air Interface of Aqueous Dispersions of a Linear Polystyrene−Poly(ethylene oxide) Diblock Copolymer. J Phys Chem B 2000. [DOI: 10.1021/jp000514k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Marcella Alexander
- Interdisciplinary Research Centre in Polymer Science, and Technology University of Durham, Durham DH1 3LE, U.K
| | - Randal W. Richards
- Interdisciplinary Research Centre in Polymer Science, and Technology University of Durham, Durham DH1 3LE, U.K
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Baker SM, Leach KA, Devereaux CE, Gragson DE. Controlled Patterning of Diblock Copolymers by Monolayer Langmuir−Blodgett Deposition. Macromolecules 2000. [DOI: 10.1021/ma992029x] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- S. M. Baker
- Department of Chemistry, 301 East 12th Street, Harvey Mudd College, Claremont, California 91711
| | - K. A. Leach
- Department of Chemistry, 301 East 12th Street, Harvey Mudd College, Claremont, California 91711
| | - C. E. Devereaux
- Department of Chemistry, 301 East 12th Street, Harvey Mudd College, Claremont, California 91711
| | - D. E. Gragson
- Department of Chemistry, 301 East 12th Street, Harvey Mudd College, Claremont, California 91711
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Webster J, Langridge S. Applications of index matching in reflectometry, SANS and Brewster angle microscopy. Curr Opin Colloid Interface Sci 1999. [DOI: 10.1016/s1359-0294(99)00040-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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