Large, Reversible, and Coherent Domain Spacing Dilation Driven by Crystallization under Soft Lamellar Confinement.
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| Title: | Large, Reversible, and Coherent Domain Spacing Dilation Driven by Crystallization under Soft Lamellar Confinement. |
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| Authors: | Burns, Adam B.1, Register, Richard A.1 register@princeton.edu |
| Source: | Macromolecules. 10/24/2017, Vol. 50 Issue 20, p8106-8116. 11p. |
| Subjects: | Glass transitions, Crystallization, Block copolymers, Propanols, Crystal structure, Hydrogenation |
| Abstract: | Crystallization within lamellar block copolymer microdomains, at temperatures above the glass transition of the amorphous block--a form of "soft", one-dimensional confinement--is investigated in a series of hydrogenated diblocks of norbornene and hexafluoroisopropanol-substituted norbornene, abbreviated hPN-hPHFAN. Crystallization results in a large (up to 23%) increase in the lamellar period (d), but in contrast to a multitude of previous reports--where large changes in d signify breakout of the crystallites from the microdomains, such that the initial and final domain structures and orientations bear no coherent relationship to each other--the hPN crystallites in hPN-hPHFAN remain confined within the microphase-separated lamellae, as revealed by small-angle X-ray scattering on highly oriented flow-aligned specimens. As the d-spacing dilates, the lamellae contract affinely in the lateral directions (as measured by confocal optical microscopy on a millimeter-scale flow-aligned specimen); dimensional changes in the macroscopic specimen (millimeter scale) precisely track the changes in d (?50 nm scale). The increase in d, and concomitant changes in the macroscopic specimen dimensions, are fully reversible on melting, over multiple melting-recrystallization cycles. The crystallites are found to be oriented with the b-axis parallel to the microdomain interfaces and the crystal stems tilted with respect to the lamellar normal. In this orientation, the crystal thickness is limited by the thickness of the hPN domains, such that the domain spacing increase is driven by the enhanced thermodynamic stability of thicker hPN crystals. [ABSTRACT FROM AUTHOR] |
| Copyright of Macromolecules is the property of American Chemical Society and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Large, Reversible, and Coherent Domain Spacing Dilation Driven by Crystallization under Soft Lamellar Confinement. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Burns%2C+Adam+B%2E%22">Burns, Adam B.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Register%2C+Richard+A%2E%22">Register, Richard A.</searchLink><relatesTo>1</relatesTo><i> register@princeton.edu</i> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Macromolecules%22">Macromolecules</searchLink>. 10/24/2017, Vol. 50 Issue 20, p8106-8116. 11p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Glass+transitions%22">Glass transitions</searchLink><br /><searchLink fieldCode="DE" term="%22Crystallization%22">Crystallization</searchLink><br /><searchLink fieldCode="DE" term="%22Block+copolymers%22">Block copolymers</searchLink><br /><searchLink fieldCode="DE" term="%22Propanols%22">Propanols</searchLink><br /><searchLink fieldCode="DE" term="%22Crystal+structure%22">Crystal structure</searchLink><br /><searchLink fieldCode="DE" term="%22Hydrogenation%22">Hydrogenation</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Crystallization within lamellar block copolymer microdomains, at temperatures above the glass transition of the amorphous block--a form of "soft", one-dimensional confinement--is investigated in a series of hydrogenated diblocks of norbornene and hexafluoroisopropanol-substituted norbornene, abbreviated hPN-hPHFAN. Crystallization results in a large (up to 23%) increase in the lamellar period (d), but in contrast to a multitude of previous reports--where large changes in d signify breakout of the crystallites from the microdomains, such that the initial and final domain structures and orientations bear no coherent relationship to each other--the hPN crystallites in hPN-hPHFAN remain confined within the microphase-separated lamellae, as revealed by small-angle X-ray scattering on highly oriented flow-aligned specimens. As the d-spacing dilates, the lamellae contract affinely in the lateral directions (as measured by confocal optical microscopy on a millimeter-scale flow-aligned specimen); dimensional changes in the macroscopic specimen (millimeter scale) precisely track the changes in d (?50 nm scale). The increase in d, and concomitant changes in the macroscopic specimen dimensions, are fully reversible on melting, over multiple melting-recrystallization cycles. The crystallites are found to be oriented with the b-axis parallel to the microdomain interfaces and the crystal stems tilted with respect to the lamellar normal. In this orientation, the crystal thickness is limited by the thickness of the hPN domains, such that the domain spacing increase is driven by the enhanced thermodynamic stability of thicker hPN crystals. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Macromolecules is the property of American Chemical Society and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1021/acs.macromol.7b01632 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 11 StartPage: 8106 Subjects: – SubjectFull: Glass transitions Type: general – SubjectFull: Crystallization Type: general – SubjectFull: Block copolymers Type: general – SubjectFull: Propanols Type: general – SubjectFull: Crystal structure Type: general – SubjectFull: Hydrogenation Type: general Titles: – TitleFull: Large, Reversible, and Coherent Domain Spacing Dilation Driven by Crystallization under Soft Lamellar Confinement. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Burns, Adam B. – PersonEntity: Name: NameFull: Register, Richard A. IsPartOfRelationships: – BibEntity: Dates: – D: 24 M: 10 Text: 10/24/2017 Type: published Y: 2017 Identifiers: – Type: issn-print Value: 00249297 Numbering: – Type: volume Value: 50 – Type: issue Value: 20 Titles: – TitleFull: Macromolecules Type: main |
| ResultId | 1 |
