Polydisperse Polymer Brushes: Internal Structure, Critical Behavior, and Interaction with Flow.
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| Title: | Polydisperse Polymer Brushes: Internal Structure, Critical Behavior, and Interaction with Flow. |
|---|---|
| Authors: | Shuanhu Qi1 qish@uni-mainz.de, Klushin, Leonid I.2, Skvortsov, Alexander M.3, Schmid, Friederike1 |
| Source: | Macromolecules. Dec2016, Vol. 49 Issue 24, p9665-9683. 19p. |
| Subjects: | Polydisperse polymers, Polymerization, Monte Carlo method, Hydrodynamics, Chain-termination reactions |
| Abstract: | We study the effect of polydispersity on the structure of polymer brushes by analytical theory, a numerical self-consistent field approach, and Monte Carlo simulations. The polydispersity is represented by the Schulz-Zimm chain-length distribution. We specifically focus on three different polydispersities representing sharp, moderate, and extremely wide chain length distributions and derive explicit analytical expressions for the chain end distributions in these brushes. The results are in very good agreement with numerical data obtained with self-consistent field calculations and Monte Carlo simulations. With increasing polydispersity, the brush density profile changes from convex to concave, and for given average chain length Nn and grafting density σ, the brush height H is found to scale as (H/Hmono - 1) ∝ (Nw/Nn - 1)1/2 over a wide range of polydispersity indices Nw/Nn (here Hmono is the height of the corresponding monodisperse brush). Chain end fluctuations are found to be strongly suppressed already at very small polydispersity. On the basis of this observation, we introduce the concept of the brush as a near-critical system with two parameters (scaling variables), (Nnσ2/3)-1 and (Nw/Nn - 1)1/2, controlling the distance from the critical point. This approach provides a good description of the simulation data. Finally, we study the hydrodynamic penetration length lp for brush-coated surfaces in flow. We find that it generally increases with polydispersity. The scaling behavior crosses over from lp - Nn1/2-1/6 for monodisperse and weakly polydisperse brushes to lp - Nn2/3 for strongly polydisperse brushes. [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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| Header | DbId: egs DbLabel: Engineering Source An: 120464543 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Polydisperse Polymer Brushes: Internal Structure, Critical Behavior, and Interaction with Flow. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Shuanhu+Qi%22">Shuanhu Qi</searchLink><relatesTo>1</relatesTo><i> qish@uni-mainz.de</i><br /><searchLink fieldCode="AR" term="%22Klushin%2C+Leonid+I%2E%22">Klushin, Leonid I.</searchLink><relatesTo>2</relatesTo><br /><searchLink fieldCode="AR" term="%22Skvortsov%2C+Alexander+M%2E%22">Skvortsov, Alexander M.</searchLink><relatesTo>3</relatesTo><br /><searchLink fieldCode="AR" term="%22Schmid%2C+Friederike%22">Schmid, Friederike</searchLink><relatesTo>1</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Macromolecules%22">Macromolecules</searchLink>. Dec2016, Vol. 49 Issue 24, p9665-9683. 19p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Polydisperse+polymers%22">Polydisperse polymers</searchLink><br /><searchLink fieldCode="DE" term="%22Polymerization%22">Polymerization</searchLink><br /><searchLink fieldCode="DE" term="%22Monte+Carlo+method%22">Monte Carlo method</searchLink><br /><searchLink fieldCode="DE" term="%22Hydrodynamics%22">Hydrodynamics</searchLink><br /><searchLink fieldCode="DE" term="%22Chain-termination+reactions%22">Chain-termination reactions</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: We study the effect of polydispersity on the structure of polymer brushes by analytical theory, a numerical self-consistent field approach, and Monte Carlo simulations. The polydispersity is represented by the Schulz-Zimm chain-length distribution. We specifically focus on three different polydispersities representing sharp, moderate, and extremely wide chain length distributions and derive explicit analytical expressions for the chain end distributions in these brushes. The results are in very good agreement with numerical data obtained with self-consistent field calculations and Monte Carlo simulations. With increasing polydispersity, the brush density profile changes from convex to concave, and for given average chain length Nn and grafting density σ, the brush height H is found to scale as (H/Hmono - 1) ∝ (Nw/Nn - 1)1/2 over a wide range of polydispersity indices Nw/Nn (here Hmono is the height of the corresponding monodisperse brush). Chain end fluctuations are found to be strongly suppressed already at very small polydispersity. On the basis of this observation, we introduce the concept of the brush as a near-critical system with two parameters (scaling variables), (Nnσ2/3)-1 and (Nw/Nn - 1)1/2, controlling the distance from the critical point. This approach provides a good description of the simulation data. Finally, we study the hydrodynamic penetration length lp for brush-coated surfaces in flow. We find that it generally increases with polydispersity. The scaling behavior crosses over from lp - Nn1/2-1/6 for monodisperse and weakly polydisperse brushes to lp - Nn2/3 for strongly polydisperse brushes. [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.6b02026 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 19 StartPage: 9665 Subjects: – SubjectFull: Polydisperse polymers Type: general – SubjectFull: Polymerization Type: general – SubjectFull: Monte Carlo method Type: general – SubjectFull: Hydrodynamics Type: general – SubjectFull: Chain-termination reactions Type: general Titles: – TitleFull: Polydisperse Polymer Brushes: Internal Structure, Critical Behavior, and Interaction with Flow. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Shuanhu Qi – PersonEntity: Name: NameFull: Klushin, Leonid I. – PersonEntity: Name: NameFull: Skvortsov, Alexander M. – PersonEntity: Name: NameFull: Schmid, Friederike IsPartOfRelationships: – BibEntity: Dates: – D: 27 M: 12 Text: Dec2016 Type: published Y: 2016 Identifiers: – Type: issn-print Value: 00249297 Numbering: – Type: volume Value: 49 – Type: issue Value: 24 Titles: – TitleFull: Macromolecules Type: main |
| ResultId | 1 |
