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Ma M, Fu Y. Electromechanical response of lamellar forming ionic diblock copolymer thin films. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.138817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Martin JM, Li W, Delaney KT, Fredrickson GH. SCFT Study of Diblock Copolymer Melts in Electric Fields: Selective Stabilization of Orthorhombic Fddd Network Phase. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b00394] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Xi Y, Pozzo LD. Electric field directed formation of aligned conjugated polymer fibers. SOFT MATTER 2017; 13:3894-3908. [PMID: 28488710 DOI: 10.1039/c7sm00485k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Alternating current (AC) electric fields effectively align poly(3-alkylthiophene) (P3AT) fibers during a one-dimensional crystallization process. Structural, mechanical and electrical properties have been probed using microscopy, small angle neutron scattering (SANS), atomic force microscopy (AFM), X-ray diffraction (XRD), rheology, UV-Vis spectroscopy, and dielectric spectroscopy. Optimum frequency and amplitudes were identified for specific P3AT concentrations and for variable solvent quality. Optical microscopy along with SANS and XRD demonstrate alignment persists over both micrometer and nanometer length scales. Small amplitude oscillatory shear rheology also showed that the shear modulus increased for aligned fibers. The structural changes were correlated to improvements in electric conductivity as probed by dielectric spectroscopy. XRD experiments performed with variable sample orientations also showed that the P3HT π-π stacking direction was aligned parallel to the direction of the fiber axis. Electric field alignment was also possible for other alkyl-thiophene polymers and for polymers with simple backbone repeat units.
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Affiliation(s)
- Yuyin Xi
- Department of Chemical Engineering, University of Washington, Seattle, WA 98195, USA.
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Mukherjee A, Ankit K, Reiter A, Selzer M, Nestler B. Electric-field-induced lamellar to hexagonally perforated lamellar transition in diblock copolymer thin films: kinetic pathways. Phys Chem Chem Phys 2016; 18:25609-25620. [PMID: 27722519 DOI: 10.1039/c6cp04903f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Symmetric block-copolymers, hitherto, are well known to evolve into parallel, perpendicular and mixed lamellar morphologies under the concomitant influence of an electric field and substrate affinity. In the present work, we show that an additional imposed confinement can effectuate a novel parallel lamellar to hexagonally perforated lamellar (HPL) transition in monolayer and bilayer films. Three dimensional numerical studies are performed using the Ohta-Kawasaki functional, complemented with an exact solution of Maxwell's equation. HPL is shown to stabilize at large substrate affinity in a narrow region of the phase diagram between parallel and perpendicular lamellar transitions in ultra-thin films. Additionally, we also identify perforated lamellae as intermediate structures during parallel-to-perpendicular lamellar transition. A systematic analysis using Minkowski functionals yields deeper insights into the associated kinetic pathways.
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Affiliation(s)
- Arnab Mukherjee
- Institute of Materials and Processes, Karlsruhe University of Applied Sciences, Moltkestr. 30, 76133, Karlsruhe, Germany. and Institute of Applied Materials - Computational Materials Science, Karlsruhe Institute of Technology, Haid-und-Neu str. 7, 76131, Karlsruhe, Germany
| | - Kumar Ankit
- Institute of Applied Materials - Computational Materials Science, Karlsruhe Institute of Technology, Haid-und-Neu str. 7, 76131, Karlsruhe, Germany
| | - Andreas Reiter
- Institute of Applied Materials - Computational Materials Science, Karlsruhe Institute of Technology, Haid-und-Neu str. 7, 76131, Karlsruhe, Germany
| | - Michael Selzer
- Institute of Materials and Processes, Karlsruhe University of Applied Sciences, Moltkestr. 30, 76133, Karlsruhe, Germany. and Institute of Applied Materials - Computational Materials Science, Karlsruhe Institute of Technology, Haid-und-Neu str. 7, 76131, Karlsruhe, Germany
| | - Britta Nestler
- Institute of Materials and Processes, Karlsruhe University of Applied Sciences, Moltkestr. 30, 76133, Karlsruhe, Germany. and Institute of Applied Materials - Computational Materials Science, Karlsruhe Institute of Technology, Haid-und-Neu str. 7, 76131, Karlsruhe, Germany
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Orizaga S, Glasner K. Instability and reorientation of block copolymer microstructure by imposed electric fields. Phys Rev E 2016; 93:052504. [PMID: 27300942 DOI: 10.1103/physreve.93.052504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Indexed: 06/06/2023]
Abstract
The influence of electric fields on lamellar block copolymer microstructure is studied in the context of a density functional model and its sharp interface limit. A free boundary problem for domain interfaces of strongly segregated polymers is derived, which includes coupling of interface and electric field orientation. The linearized dynamics of lamellar configurations is computed in this context, leading to quantitative criteria for instability as a function of pattern wavelength, field magnitude, and orientation. Numerical simulations of the full model in two and three dimensions are used to study the nonlinear development of instabilities. In three dimensions, sufficiently large electric field magnitude always leads to instability. In two dimensions, the field has either stabilizing or destabilizing effects depending on the misorientation of the field and pattern. Even when linear instabilities are present, the dynamics can lead to stable corrugated domain interfaces which do not align with the electric field. Sufficiently high field strengths, on the other hand, produce topological rearrangement which may lead to alignment.
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Affiliation(s)
- Saulo Orizaga
- Department of Mathematics, University of Arizona, 617 N. Santa Rita Tucson, Arizona 85721, USA
| | - Karl Glasner
- Department of Mathematics, University of Arizona, 617 N. Santa Rita Tucson, Arizona 85721, USA
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Wu J, Wang X, Ji Y, He L, Li S. Phase diagrams of diblock copolymers in electric fields: a self-consistent field theory study. Phys Chem Chem Phys 2016; 18:10309-19. [PMID: 27020849 DOI: 10.1039/c5cp08030d] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We investigated the phase diagrams of diblock copolymers in external electrostatic fields by using real-space self-consistent field theory. The lamella, cylinder, sphere, and ellipsoid structures were observed and analyzed by their segment distributions, which were arranged to two types of phase diagrams to examine the phase behavior in weak and strong electric fields. One type was constructed on the basis of Flory-Huggins interaction parameter and volume fraction. We identified an ellipsoid structure with a body-centered cuboid arrangement as a stable phase and discussed the shift of phase boundaries in the electric fields. The other type of phase diagrams was established on the basis of the dielectric constants of two blocks in the electric fields. We then determined the regions of ellipsoid phase in the phase diagrams to examine the influence of dielectric constants on the phase transition between ellipsoidal and hexagonally packed cylinder phases. A general agreement was obtained by comparing our results with those described in previous experimental and theoretical studies.
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Affiliation(s)
- Ji Wu
- Department of Physics, Wenzhou University, Wenzhou, Zhejiang 325035, China.
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Mukherjee A, Mukherjee R, Ankit K, Bhattacharya A, Nestler B. Influence of substrate interaction and confinement on electric-field-induced transition in symmetric block-copolymer thin films. Phys Rev E 2016; 93:032504. [PMID: 27078402 DOI: 10.1103/physreve.93.032504] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Indexed: 11/07/2022]
Abstract
In the present work, we study morphologies arising due to competing substrate interaction, electric field, and confinement effects on a symmetric diblock copolymer. We employ a coarse-grained nonlocal Cahn-Hilliard phenomenological model taking into account the appropriate contributions of substrate interaction and electrostatic field. The proposed model couples the Ohta-Kawasaki functional with Maxwell equation of electrostatics, thus alleviating the need for any approximate solution used in previous studies. We calculate the phase diagram in electric-field-substrate strength space for different film thicknesses. In addition to identifying the presence of parallel, perpendicular, and mixed lamellae phases similar to analytical calculations, we also find a region in the phase diagram where hybrid morphologies (combination of two phases) coexist. These hybrid morphologies arise either solely due to substrate affinity and confinement or are induced due to the applied electric field. The dependence of the critical fields for transition between the various phases on substrate strength, film thickness, and dielectric contrast is discussed. Some preliminary 3D results are also presented to corroborate the presence of hybrid morphologies.
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Affiliation(s)
- Arnab Mukherjee
- Institute of Materials Processes, Karlsruhe University of Applied Sciences, Moltkestrasse 30, 76133, Karlsruhe, Germany.,Institute of Applied Materials-Computational Materials Science, Karlsruhe Institute of Technology, Haid-und-Neu strasse 7, 76131, Karlsruhe, Germany
| | - Rajdip Mukherjee
- Department of Materials Science and Engineering, Indian Institute of Technology Kanpur, 208016, Kanpur, India
| | - Kumar Ankit
- Institute of Applied Materials-Computational Materials Science, Karlsruhe Institute of Technology, Haid-und-Neu strasse 7, 76131, Karlsruhe, Germany
| | - Avisor Bhattacharya
- Institute of Materials Processes, Karlsruhe University of Applied Sciences, Moltkestrasse 30, 76133, Karlsruhe, Germany.,Institute of Applied Materials-Computational Materials Science, Karlsruhe Institute of Technology, Haid-und-Neu strasse 7, 76131, Karlsruhe, Germany
| | - Britta Nestler
- Institute of Materials Processes, Karlsruhe University of Applied Sciences, Moltkestrasse 30, 76133, Karlsruhe, Germany.,Institute of Applied Materials-Computational Materials Science, Karlsruhe Institute of Technology, Haid-und-Neu strasse 7, 76131, Karlsruhe, Germany
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Dehghan A, Schick M, Shi AC. Effect of mobile ions on the electric field needed to orient charged diblock copolymer thin films. J Chem Phys 2015; 143:134902. [PMID: 26450329 DOI: 10.1063/1.4931826] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We examine the behavior of lamellar phases of charged/neutral diblock copolymer thin films containing mobile ions in the presence of an external electric field. We employ self-consistent field theory and focus on the aligning effect of the electric field on the lamellae. Of particular interest are the effects of the mobile ions on the critical field, the value required to reorient the lamellae from the parallel configuration favored by the surface interaction to the perpendicular orientation favored by the field. We find that the critical field depends strongly on whether the neutral or charged species is favored by the substrates. In the case in which the neutral species is favored, the addition of charges decreases the critical electric field significantly. The effect is greater when the mobile ions are confined to the charged lamellae. In contrast, when the charged species is favored by the substrate, the addition of mobile ions stabilizes the parallel configuration and thus results in an increase in the critical electric field. The presence of ions in the system introduces a new mixed phase in addition to those reported previously.
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Affiliation(s)
- Ashkan Dehghan
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - M Schick
- Department of Physics, University of Washington, Seattle, Washington 98195, USA
| | - An-Chang Shi
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
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Zhang L, Wang PY. Selectivity and temperature dependence of phase and phase transition in diblock copolymer solution. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2011; 34:43. [PMID: 21505971 DOI: 10.1140/epje/i2011-11043-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2010] [Accepted: 03/28/2011] [Indexed: 05/30/2023]
Abstract
In order to study the effects of solvent selectivity and temperature on phase behavior and transition of diblock copolymer solution, self-consistent field theory is modified to incorporate the short-range interaction and non-local effects. Inhomogeneous free-energy density is shown to be dependent on solvent selectivity, temperature and copolymer concentration. Enthalpic quantity and entropic contributions are crucial to phase diagrams of diblock copolymer solution. Three selective strengths of solvent --weak, moderate and strong-- are chosen for comparison. For a weakly selective solvent, theoretical and experimental results illustrate the same variation tendency in the phase boundary of the order-disorder transition for a symmetric diblock of polystyrene and polyisoprene. Self-consistent field equations can be used to calculate the exact FCC-BCC structural phase transition temperatures in moderately and strongly selective solvents. Detailed comparison with the experimental phase diagrams including lamellar, cylindrical and spherical structures is presented.
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Affiliation(s)
- Lingyun Zhang
- Key Laboratory of Soft Matter Physics, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.
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Affiliation(s)
- Xingkun Man
- Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Ramat Aviv 69978, Tel Aviv, Israel
| | - David Andelman
- Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Ramat Aviv 69978, Tel Aviv, Israel
| | - Henri Orland
- Institut de Physique Théorique, CEA-Saclay, F-91191 Gif-sur-Yvette Cedex, France
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Jain S, Chapman WG. Effect of confinement on the ordering of symmetric diblock copolymers: application of interfacial statistical associating fluid theory. Mol Phys 2009. [DOI: 10.1080/00268970802676040] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Andelman D, Rosensweig RE. Modulated Phases: Review and Recent Results. J Phys Chem B 2008; 113:3785-98. [DOI: 10.1021/jp807770n] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- David Andelman
- Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
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Affiliation(s)
- Marianne Heckmann
- Institut für Festkörperphysik, Technische Universität Darmstadt, Darmstadt, Germany
| | - Barbara Drossel
- Institut für Festkörperphysik, Technische Universität Darmstadt, Darmstadt, Germany
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Ly DQ, Honda T, Kawakatsu T, Zvelindovsky AV. Hexagonally Perforated Lamella-to-Cylinder Transition in a Diblock Copolymer Thin Film under an Electric Field. Macromolecules 2008. [DOI: 10.1021/ma0708850] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Dung Q. Ly
- Centre for Materials Science, Department of Physics, Astronomy and Mathematics, University of Central Lancashire, Preston, PR1 2HE, United Kingdom; ZEON Corporation, 1-6-2, Marunouchi, Chioda-ku, Tokyo 100-8246, Japan; and Department of Physics, Tohoku University, Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Takashi Honda
- Centre for Materials Science, Department of Physics, Astronomy and Mathematics, University of Central Lancashire, Preston, PR1 2HE, United Kingdom; ZEON Corporation, 1-6-2, Marunouchi, Chioda-ku, Tokyo 100-8246, Japan; and Department of Physics, Tohoku University, Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Toshihiro Kawakatsu
- Centre for Materials Science, Department of Physics, Astronomy and Mathematics, University of Central Lancashire, Preston, PR1 2HE, United Kingdom; ZEON Corporation, 1-6-2, Marunouchi, Chioda-ku, Tokyo 100-8246, Japan; and Department of Physics, Tohoku University, Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Andrei V. Zvelindovsky
- Centre for Materials Science, Department of Physics, Astronomy and Mathematics, University of Central Lancashire, Preston, PR1 2HE, United Kingdom; ZEON Corporation, 1-6-2, Marunouchi, Chioda-ku, Tokyo 100-8246, Japan; and Department of Physics, Tohoku University, Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
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Wu XF, Dzenis YA. Phase-field modeling of the formation of lamellar nanostructures in diblock copolymer thin films under inplanar electric fields. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2008; 77:031807. [PMID: 18517414 DOI: 10.1103/physreve.77.031807] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2007] [Revised: 02/04/2008] [Indexed: 05/26/2023]
Abstract
Recent experiments show that external inplanar electric field can be employed to guide the molecular self-assembly in diblock copolymer (BCP) thin films to form lamellar nanostructures with potential applications in nanotechnology. We study this self-assembly process through a detailed coarse-grained phase-separation modeling. During the process, the free energy of the BCP films is modeled as the Ginzburg-Landau free energy with nonlocal interaction and electrostatic coupling. The resulting Cahn-Hilliard (CH) equation is solved using an efficient semi-implicit Fourier-spectral algorithm. Numerical results show that the morphology of order parameter formed in either symmetric or asymmetric BCP thin films is strongly influenced by the electric field. For symmetrical BCPs, highly ordered lamellar nanostructures evolved along the direction of the electric field. Phase nucleation and dislocation climbing in the BCP films predicted by the numerical simulation are in a good agreement with those observed in recent BCP electronanolithography. For asymmetrical BCPs, numerical simulation shows that nanodots are guided to align to the electric field. Furthermore, in the case of high electric field, nanodots formed in asymmetrical BCPs may further convert into highly ordered lamellar nanostructures (sphere-to-cylinder transition) parallel to the electric field. Effects of the magnitude of electric field, BCP asymmetry, and molecular interaction of BCPs on the self-assembly process are examined in detail using the numerical scheme developed in this study. The present study can be used for the prediction of the formation of nanostructures in BCP thin films and the quality control of BCP-based nanomanufacturing through optimizing the external electric fields.
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Affiliation(s)
- Xiang-Fa Wu
- Department of Engineering Mechanics, Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0526, USA.
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