1
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Rappoport S, Chrysostomou V, Kafetzi M, Pispas S, Talmon Y. Self-Aggregation in Aqueous Media of Amphiphilic Diblock and Random Block Copolymers Composed of Monomers with Long Side Chains. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:3380-3390. [PMID: 36802652 DOI: 10.1021/acs.langmuir.2c03294] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Amphiphilic diblock copolymers and hydrophobically modified random block copolymers can self-assemble into different structures in a selective solvent. The formed structures depend on the copolymer properties, such as the ratio between the hydrophilic and the hydrophobic segments and their nature. In this work, we characterize by cryogenic transmission electron microscopy (cryo-TEM) and dynamic light scattering (DLS) the amphiphilic copolymers poly(2-dimethylamino ethyl methacrylate)-b-poly(lauryl methacrylate) (PDMAEMA-b-PLMA) and their quaternized derivatives QPDMAEMA-b-PLMA at different ratios between the hydrophilic and the hydrophobic segments. We present the various structures formed by these copolymers, including spherical and cylindrical micelles, as well as unilamellar and multilamellar vesicles. We also examined by these methods the random diblock copolymers poly(2-(dimethylamino) ethyl methacrylate)-b-poly(oligo(ethylene glycol) methyl ether methacrylate) (P(DMAEMA-co-Q6/12DMAEMA)-b-POEGMA), which are partially hydrophobically modified by iodohexane (Q6) or iodododecane (Q12). The polymers with a small POEGMA block did not form any specific nanostructure, while a polymer with a larger POEGMA block formed spherical and cylindrical micelles. This nanostructural characterization could lead to the efficient design and use of these polymers as carriers of hydrophobic or hydrophilic compounds for biomedical applications.
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Affiliation(s)
- Sapir Rappoport
- Department of Chemical Engineering and The Russell Berrie Nanotechnology Institute (RBNI), Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Varvara Chrysostomou
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635 Athens, Greece
| | - Martha Kafetzi
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635 Athens, Greece
| | - Stergios Pispas
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635 Athens, Greece
| | - Yeshayahu Talmon
- Department of Chemical Engineering and The Russell Berrie Nanotechnology Institute (RBNI), Technion-Israel Institute of Technology, Haifa 3200003, Israel
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2
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Hils C, Schmelz J, Drechsler M, Schmalz H. Janus Micelles by Crystallization-Driven Self-Assembly of an Amphiphilic, Double-Crystalline Triblock Terpolymer. J Am Chem Soc 2021; 143:15582-15586. [PMID: 34529422 DOI: 10.1021/jacs.1c08076] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Surface-compartmentalized micellar nanostructures (Janus and patchy micelles) have gained increasing interest due to their unique properties opening highly relevant applications, e.g., as efficient particulate surfactants, compatibilizers in polymer blends, or templates for catalytically active nanoparticles. We present a facile method for the production of worm-like Janus micelles based on crystallization-driven self-assembly of a double-crystalline triblock terpolymer with a crystallizable polyethylene middle block and two highly incompatible corona blocks, polystyrene and poly(ethylene oxide). This approach enables the production of amphiphilic Janus micelles with excellent interfacial activity by a comparably simple heating and cooling protocol directly in solution.
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Affiliation(s)
- Christian Hils
- Macromolecular Chemistry II, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Joachim Schmelz
- Macromolecular Chemistry II, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Markus Drechsler
- Keylab Electron and Optical Microscopy, Bavarian Polymer Institute, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Holger Schmalz
- Macromolecular Chemistry II, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany.,Keylab Synthesis and Molecular Characterization, Bavarian Polymer Institute, Universitätsstraße 30, 95447 Bayreuth, Germany
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3
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Abstract
Bottlebrush polymers (BBPs), composed of relatively short polymeric side chains densely grafted on a polymer backbone, exhibit many unique characteristics and hold promise for a variety of applications. This Perspective focuses on environmentally induced shape-changing behavior of BBPs at interface and in solution, particularly worm/star-globule shape transitions. While BBPs with a single type of homopolymer or random copolymer side chains have been shown to undergo pronounced worm-to-globule shape changes in response to external stimuli, the collapsed brushes are unstable and prone to aggregation. By introducing a second, solvophilic polymer into the side chains, either as a distinct type of side chain or as the outer block of block copolymer side chains, the collapsed brushes not only are stabilized but also create unimolecular micellar nanostructures, which can be used for, e.g., encapsulation and delivery of substances. The current challenges in the design, synthesis, and characterization of stimuli-responsive shape-changing BBPs are discussed.
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Affiliation(s)
- Bin Zhao
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
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4
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Zhang Y, Xi S, Parambathu AV, Chapman WG. Density functional study of one- and two-component bottlebrush molecules in solvents of varying quality. Mol Phys 2020. [DOI: 10.1080/00268976.2020.1767812] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Yuchong Zhang
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | - Shun Xi
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | | | - Walter G. Chapman
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
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5
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Dutta S, Pan T, Sing CE. Bridging Simulation Length Scales of Bottlebrush Polymers Using a Wormlike Cylinder Model. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b00363] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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6
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Dutta S, Wade MA, Walsh DJ, Guironnet D, Rogers SA, Sing CE. Dilute solution structure of bottlebrush polymers. SOFT MATTER 2019; 15:2928-2941. [PMID: 30724969 DOI: 10.1039/c9sm00033j] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Bottlebrush polymers are a class of macromolecules that have recently found use in a wide variety of materials, ranging from lubricating brushes and nanostructured coatings to elastomeric gels that exhibit structural colors. These polymers are characterized by dense branches extending from a central backbone and thus have properties distinct from linear polymers. It remains a challenge to specifically understand conformational properties of these molecules, due to the wide range of architectural parameters that can be present in a system, and thus there is a need to accurately characterize and model these molecules. In this paper, we use a combination of viscometry, light scattering, and computer simulations to gain insight into the conformational properties of dilute solution bottlebrush polymers. We focus on a series of model bottlebrushes consisting of a poly(norbornene) (PNB) backbone with poly(lactic acid) (PLA) side chains. We demonstrate that intrinsic viscosity and hydrodynamic radius are experimental observations sensitive to molecular architecture, exhibiting distinct differences with different choices of branches and backbone lengths. Informed by the atomistic structure of this PNB-PLA system, we rationalize a coarse-grained simulation model that we evaluate using a combination of Brownian dynamics and Monte Carlo simulations. We show that this exhibits quantitative matching to experimental results, enabling us to characterize the overall shape of the bottlebrush via a number of metrics that can be extended to more general bottlebrush architectures.
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Affiliation(s)
- Sarit Dutta
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
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7
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Erukhimovich I. Weak Segregation Theory and Multicompartment Spherical Micelles. POLYMER SCIENCE SERIES C 2018. [DOI: 10.1134/s1811238218020066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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8
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Cruz M, Xu J, Yu Q, Guerin G, Manners I, Winnik MA. Visualizing Nanoscale Coronal Segregation in Rod-Like Micelles Formed by Co-Assembly of Binary Block Copolymer Blends. Macromol Rapid Commun 2018; 39:e1800397. [PMID: 30091837 DOI: 10.1002/marc.201800397] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 07/06/2018] [Indexed: 12/24/2022]
Abstract
Mixed micelles formed by co-assembly of pairs of block copolymers (BCPs) can develop novel morphologies and generate useful properties not accessible from homomicelles. For micelles consisting of two different polymers in the corona, identifying the location of the corona chains is a critical part of morphology characterization. Coronal segregation in mixed micelle is often characterized by transmission electron microscopy in combination with selective staining of individual polymers. In this study, Karstedt's catalyst is used for selective Pt(0)-olefin coordination staining of polyisoprene (PI) and poly(methylvinylsiloxane) (PMVS) corona chains in the presence of poly(dimethylsiloxane) (PDMS) corona chains in cylindrical mixed micelles with a crystalline poly(ferrocenyldimethylsilane) (PFS) core. Previous experiments using OsO4 as a stain did not enable visualization of nanoscale coronal segregation in mixed micelles obtained from co-assembly of PFS-b-PI and PFS-b-PDMS, as well as PFS-b-PMVS and PFS-b-PDMS.
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Affiliation(s)
- Menandro Cruz
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S 3H6, Canada
| | - Jiangping Xu
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S 3H6, Canada
| | - Qing Yu
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S 3H6, Canada
| | - Gerald Guerin
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S 3H6, Canada
| | - Ian Manners
- School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.K
| | - Mitchell A Winnik
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S 3H6, Canada
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9
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Pannuzzo M, Tilton RD, Deserno M. Responsive behavior of a branched-chain polymer network: a molecular dynamics study. SOFT MATTER 2018; 14:6485-6495. [PMID: 30043771 DOI: 10.1039/c7sm02096a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Smart polymer hydrogels, which can undergo structural and volume phase transitions in response to external stimuli, have gained much attention for their widespread technological applications. Compared to linear polymers, branched chains offer more extensive opportunities to rationally design functional materials, since they permit more extensive structural tunability-for instance by adjusting the balance between hydrophobic and hydrophilic units, the grafting fraction of backbone monomers, or the side chain length, topology, and solubility. Here we conduct coarse-grained molecular dynamics simulations to assess how well generic physical principles capture this complex interplay of tuning parameters, specifically when building networks from complex branched chains with a hydrophobic backbone. Swollen chains collapse upon reducing side chain solubility, length, and grafting density, but neither the sharpness of this transition nor its dynamic range, if measured via chain extension, depends monotonically on these parameters. Networks comprising such chains are more swollen and exhibit even sharper transitions, but their higher responsiveness goes along with a swelling ratio that falls behind that of single chains.
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Affiliation(s)
- Martina Pannuzzo
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
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10
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Palacios-Hernandez T, Luo H, Garcia EA, Pacheco LA, Herrera-Alonso M. Nanoparticles from Amphiphilic Heterografted Macromolecular Brushes with Short Backbones. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b00300] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Teresa Palacios-Hernandez
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Hanying Luo
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Elena Alexandra Garcia
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Lazaro A. Pacheco
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Margarita Herrera-Alonso
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
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11
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12
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Leuty GM, Tsige M, Grest GS, Rubinstein M. Tension Amplification in Tethered Layers of Bottle-Brush Polymers. Macromolecules 2016; 49:1950-1960. [PMID: 27695137 PMCID: PMC5040463 DOI: 10.1021/acs.macromol.5b02305] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Molecular dynamics simulations of a coarse-grained bead-spring model have been used to study the effects of molecular crowding on the accumulation of tension in the backbone of bottle-brush polymers tethered to a flat substrate. The number of bottle-brushes per unit surface area, Σ, as well as the lengths of the bottle-brush backbones Nbb (50 ≤ Nbb ≤ 200) and side chains Nsc (50 ≤ Nsc ≤ 200) were varied to determine how the dimensions and degree of crowding of bottle-brushes give rise to bond tension amplification along the backbone, especially near the substrate. From these simulations, we have identified three separate regimes of tension. For low Σ, the tension is due solely to intramolecular interactions and is dominated by the side chain repulsion that governs the lateral brush dimensions. With increasing Σ, the interactions between bottle-brush polymers induce compression of the side chains, transmitting increasing tension to the backbone. For large Σ, intermolecular side chain repulsion increases, forcing side chain extension and reorientation in the direction normal to the surface and transmitting considerable tension to the backbone.
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Affiliation(s)
- Gary M. Leuty
- Department of Polymer Science, The University of Akron, Akron, Ohio 44325, United States
| | - Mesfin Tsige
- Department of Polymer Science, The University of Akron, Akron, Ohio 44325, United States
| | - Gary S. Grest
- Sandia National Laboratories, Albuquerque, New Mexico 87185, United States
| | - Michael Rubinstein
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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13
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Erukhimovich I, Kriksin Y, ten Brinke G. Diamond-Forming Block Copolymers and Diamond-like Morphologies: A New Route toward Efficient Block Copolymer Membranes. Macromolecules 2015. [DOI: 10.1021/acs.macromol.5b01513] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- I. Erukhimovich
- Nesmeyanov
Institute of Organoelement Compounds, RAS, Moscow 119991, Russia
| | - Y. Kriksin
- Keldysh
Institute of Applied Mathematics, RAS, Moscow 125047, Russia
| | - G. ten Brinke
- Department
of Polymer Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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14
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Ma X, Chen C, Yang Y, Qiu F. Ripple structures of mixed homopolymer brushes grafted on cylindrical surfaces: controlling the orientation of the pattern by attuning the substrate curvatures. SOFT MATTER 2014; 10:6005-6013. [PMID: 24992228 DOI: 10.1039/c4sm00749b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We employed the strong segregation theory (SST) to study the phase structures of mixed homopolymer brushes grafted on cylindrical surfaces. We considered a simplified case in which two incompatible homopolymers have the same chain length and grafting density. Under these conditions, micro-phase separation in the brush may result in either ripple or helix structures. By comparing the free energy of the possible candidate structures, we found that the helix structure is never the most stable one, while the stability of the perpendicular and parallel ripple structures are sensitive to the curvature of the grafting substrate. It was found that the morphology orientation of the mixed homopolymer brushes can be controlled by attuning the geometry of the substrates.
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Affiliation(s)
- Xin Ma
- The State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai 200433, China.
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15
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Chen C, Tang P, Qiu F. Binary hairy nanoparticles: Recent progress in theory and simulations. ACTA ACUST UNITED AC 2014. [DOI: 10.1002/polb.23528] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Cangyi Chen
- Department of Macromolecular Science; State Key Laboratory of Molecular Engineering of Polymers, Fudan University; Shanghai 200433 China
| | - Ping Tang
- Department of Macromolecular Science; State Key Laboratory of Molecular Engineering of Polymers, Fudan University; Shanghai 200433 China
| | - Feng Qiu
- Department of Macromolecular Science; State Key Laboratory of Molecular Engineering of Polymers, Fudan University; Shanghai 200433 China
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16
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Kim IP, Kunitsa AA, Chernyak AV. NMR identification of the terminal groups of the telomers of tetrafluoroethylene with tetrahydrofuran. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2013. [DOI: 10.1134/s0036024413110137] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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17
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Szleifer I. Macromolecular mixing: Entropic templating. NATURE MATERIALS 2013; 12:693-694. [PMID: 23877397 DOI: 10.1038/nmat3728] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Affiliation(s)
- Igal Szleifer
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA.
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18
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Fytas NG, Theodorakis PE. Molecular dynamics simulations of single-component bottle-brush polymers with flexible backbones under poor solvent conditions. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:285105. [PMID: 23765452 DOI: 10.1088/0953-8984/25/28/285105] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Conformations of a single-component bottle-brush polymer with a fully flexible backbone under poor solvent conditions are studied by molecular dynamics simulations, using a coarse-grained bead-spring model with side chains of up to N = 40 effective monomers. By variation of the solvent quality and the grafting density σ with which side chains are grafted onto the flexible backbone, we study for backbone lengths of up to Nb = 100 the crossover from the brush/coil regime to the dense collapsed state. At lower temperatures, where collapsed chains with a constant monomer density are observed, the choice of the above parameters does not play any role and it is the total number of monomers that defines the dimensions of the chains. Furthermore, bottle-brush polymers with longer side chains possess higher spherical symmetry compared to polymers with lower side-chain lengths in contrast to what one may intuitively expect, as the stretching of the side chains is less important than the increase of their length. At higher temperatures, always below the Theta (Θ) temperature, coil-like configurations, similar to a single polymer chain, or brush-like configurations, similar to a homogeneous cylindrical bottle-brush polymer with a rigid backbone, are observed, depending on the choice of the particular parameters N and σ. In the crossover regime between the collapsed state (globule) and the coil/brush regime the acylindricity increases, whereas for temperatures outside of this range, bottle-brush polymers maintain a highly cylindrical symmetry in all configurational states.
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Affiliation(s)
- Nikolaos G Fytas
- Applied Mathematics Research Centre, Coventry University, Coventry CV1 5FB, UK.
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19
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Theodorakis PE, Dellago C, Kahl G. A coarse-grained model for DNA-functionalized spherical colloids, revisited: effective pair potential from parallel replica simulations. J Chem Phys 2013; 138:025101. [PMID: 23320725 DOI: 10.1063/1.4773920] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
We discuss a coarse-grained model recently proposed by Starr and Sciortino [J. Phys.: Condens. Matter 18, L347 (2006)] for spherical particles functionalized with short single DNA strands. The model incorporates two key aspects of DNA hybridization, i.e., the specificity of binding between DNA bases and the strong directionality of hydrogen bonds. Here, we calculate the effective potential between two DNA-functionalized particles of equal size using a parallel replica protocol. We find that the transition from bonded to unbonded configurations takes place at considerably lower temperatures compared to those that were originally predicted using standard simulations in the canonical ensemble. We put particular focus on DNA-decorations of tetrahedral and octahedral symmetry, as they are promising candidates for the self-assembly into a single-component diamond structure. Increasing colloid size hinders hybridization of the DNA strands, in agreement with experimental findings.
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20
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Rosenfeldt S, Lüdel F, Schulreich C, Hellweg T, Radulescu A, Schmelz J, Schmalz H, Harnau L. Patchy worm-like micelles: solution structure studied by small-angle neutron scattering. Phys Chem Chem Phys 2013; 14:12750-6. [PMID: 22880203 DOI: 10.1039/c2cp41231d] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Triblock terpolymers exhibit a rich self-organization behavior including the formation of fascinating cylindrical core-shell structures with a phase separated corona. After crystallization-induced self-assembly of polystyrene-block-polyethylene-block-poly(methyl methacrylate) triblock terpolymers (abbreviated as SEMs = Styrene-Ethylene-Methacrylates) from solution, worm-like core-shell micelles with a patchy corona of polystyrene and poly(methyl methacrylate) were observed by transmission electron microscopy. However, the solution structure is still a matter of debate. Here, we present a method to distinguish in situ between a Janus-type (two faced) and a patchy (multiple compartments) configuration of the corona. To discriminate between both models the scattering intensity must be determined mainly by one corona compartment. Contrast variation in small-angle neutron scattering enables us to focus on one compartment of the worm-like micelles. The results validate the existence of the patchy structure also in solution.
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Affiliation(s)
- Sabine Rosenfeldt
- Physikalische Chemie I, Universität Bayreuth, D-95440 Bayreuth, Germany
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21
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Binder K, Butt HJ, Floudas G, Frey H, Hsu HP, Landfester K, Kolb U, Kühnle A, Maskos M, Müllen K, Paul W, Schmidt M, Spiess HW, Virnau P. Structure Formation of Polymeric Building Blocks: Complex Polymer Architectures. FROM SINGLE MOLECULES TO NANOSCOPICALLY STRUCTURED MATERIALS 2013. [DOI: 10.1007/12_2013_230] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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22
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Binder K, Milchev A. Polymer brushes on flat and curved surfaces: How computer simulations can help to test theories and to interpret experiments. ACTA ACUST UNITED AC 2012. [DOI: 10.1002/polb.23168] [Citation(s) in RCA: 166] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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23
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Theodorakis PE, Fytas NG. A study for the static properties of symmetric linear multiblock copolymers under poor solvent conditions. J Chem Phys 2012; 136:094902. [DOI: 10.1063/1.3689303] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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24
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Maleki H, Theodorakis PE. Structure of bottle-brush brushes under good solvent conditions: a molecular dynamics study. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2011; 23:505104. [PMID: 22086109 DOI: 10.1088/0953-8984/23/50/505104] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report a simulation study for bottle-brush polymers grafted on a rigid backbone. Using a standard coarse-grained bead-spring model extensive molecular dynamics simulations for such macromolecules under good solvent conditions are performed. We consider a broad range of parameters and present numerical results for the monomer density profile, density of the untethered ends of the grafted flexible backbones and the correlation function describing the range that neighboring grafted bottle-brushes are affected by the presence of the others due to the excluded-volume interactions. The end beads of the flexible backbones of the grafted bottle-brushes do not access the region close to the rigid backbone due to the presence of the side chains of the grafted bottle-brush polymers, which stretch the chains further in the radial directions. Although a number of different correlation lengths exist as a result of the complex structure of these macromolecules, their properties can be tuned with high accuracy in good solvents. Moreover, qualitative differences with 'typical' bottle-brushes are discussed. Our results provide a first approach to characterizing such complex macromolecules with a standard bead-spring model.
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Affiliation(s)
- Hamed Maleki
- Institut für Physik, Johannes Gutenberg-Universität, Staudinger Weg 7, D-55099 Mainz, Germany.
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25
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Binder K, Müller M, Vink RLC. Phase Behavior of Polymer-Containing Systems: Recent Advances Through Computer Simulation. MACROMOL THEOR SIMUL 2011. [DOI: 10.1002/mats.201100046] [Citation(s) in RCA: 9] [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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26
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Fytas NG, Theodorakis PE. Analysis of the static properties of cluster formations in symmetric linear multiblock copolymers. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2011; 23:235106. [PMID: 21613714 DOI: 10.1088/0953-8984/23/23/235106] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We use molecular dynamics simulations to study the static properties of a single linear multiblock copolymer chain under poor solvent conditions varying the block length N, the number of blocks n, and the solvent quality by variation of the temperature T. We study the most symmetrical case, where the number of blocks of monomers of type A, n(A), equals that of monomers B, n(B) (n(A) = n(B) = n/2), the length of all blocks is the same irrespective of their type, and the potential parameters are also chosen symmetrically, as for a standard Lennard-Jones fluid. Under poor solvent conditions the chains collapse and blocks with monomers of the same type form clusters, which are phase separated from the clusters with monomers of the other type. We study the dependence of the size of the clusters formed on n, N and T. Furthermore, we discuss our results with respect to recent simulation data on the phase behaviour of such macromolecules, providing a complete picture for the cluster formations in single multiblock copolymer chains under poor solvent conditions.
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Affiliation(s)
- N G Fytas
- Department of Materials Science, University of Patras, 26504 Patras, Greece.
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Theodorakis PE, Paul W, Binder K. Analysis of the cluster formation in two-component cylindrical bottle-brush polymers under poor solvent conditions: a simulation study. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2011; 34:52. [PMID: 21607832 DOI: 10.1140/epje/i2011-11052-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Accepted: 05/09/2011] [Indexed: 05/30/2023]
Abstract
Two-component bottle-brush polymers, where flexible side chains containing N = 20, 35 and 50 effective monomers are grafted alternatingly to a rigid backbone, are studied by Molecular Dynamics simulations, varying the grafting density [Formula: see text] and the solvent quality. Whereas for poor solvents and large enough [Formula: see text] the molecular brush is a cylindrical object with monomers of different type occupying locally the two different halves of the cylinder, for intermediate values of [Formula: see text] an axially inhomogeneous structure of "pearl-necklace" type is formed, where microphase separation between monomers of different type within a cluster takes place. These "pearls" have a strongly non-spherical ellipsoidal shape, due to the fact that several side chains cluster together in one "pearl". We discuss the resulting structures in detail and we present a comparison with the single-component bottle-brush case.
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Affiliation(s)
- P E Theodorakis
- Institut für Physik, Johannes Gutenberg-Universität, Mainz, Germany.
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