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Dugger JW, Li W, Chen M, Long TE, Welbourn RJL, Skoda MWA, Browning JF, Kumar R, Lokitz BS. Nanoscale Resolution of Electric-field Induced Motion in Ionic Diblock Copolymer Thin Films. ACS APPLIED MATERIALS & INTERFACES 2018; 10:32678-32687. [PMID: 30180545 DOI: 10.1021/acsami.8b11220] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Understanding the responses of ionic block copolymers to applied electric fields is crucial when targeting applications in areas such as energy storage, microelectronics, and transducers. This work shows that the identity of counterions in ionic diblock copolymers substantially affects their responses to electric fields, demonstrating the importance of ionic species for materials design. In situ neutron reflectometry measurements revealed that thin films containing imidazolium based cationic diblock copolymers, tetrafluoroborate counteranions led to film contraction under applied electric fields, while bromide counteranions drove expansion under similar field strengths. Coarse-grained molecular dynamics simulations were used to develop a fundamental understanding of these responses, uncovering a nonmonotonic trend in thickness change as a function of field strength. This behavior was attributed to elastic responses of microphase separated diblock copolymer chains resulting from variations in interfacial tension of polymer-polymer interfaces due to the redistribution of counteranions in the presence of electric fields.
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Affiliation(s)
- Jason W Dugger
- Center for Nanophase Materials Sciences , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Wei Li
- Center for Nanophase Materials Sciences , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Mingtao Chen
- Macromolecules Innovation Institute (MII), Department of Chemistry , Virginia Polytechnic Institute and State University , Blacksburg , Virginia 24061 , United States
| | - Timothy E Long
- Macromolecules Innovation Institute (MII), Department of Chemistry , Virginia Polytechnic Institute and State University , Blacksburg , Virginia 24061 , United States
| | - Rebecca J L Welbourn
- ISIS , Science and Technology Facilities Council, Rutherford Appleton Laboratory , Didcot , OX11 0QX , U.K
| | - Maximilian W A Skoda
- ISIS , Science and Technology Facilities Council, Rutherford Appleton Laboratory , Didcot , OX11 0QX , U.K
| | - James F Browning
- Neutron Scattering Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Rajeev Kumar
- Center for Nanophase Materials Sciences , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
- Computational Sciences and Engineering Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Bradley S Lokitz
- Center for Nanophase Materials Sciences , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
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Wernecke J, Okuda H, Ogawa H, Siewert F, Krumrey M. Depth-Dependent Structural Changes in PS-b-P2VP Thin Films Induced by Annealing. Macromolecules 2014. [DOI: 10.1021/ma500642d] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Jan Wernecke
- Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, 10587 Berlin, Germany
| | - Hiroshi Okuda
- Department
of Materials Science and Engineering, Kyoto University, Yoshida Honmachi, Sakyoku, Kyoto, 606-8501, Japan
| | - Hiroki Ogawa
- SPring-8, Japan Synchrotron Radiation Research Institute , 1-1-1, Kouto,
Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Frank Siewert
- Institute
Nanometre Optics and Technology, Helmholtz Zentrum Berlin (HZB), Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - Michael Krumrey
- Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, 10587 Berlin, Germany
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