skip to main content

DOE PAGESDOE PAGES

Title: Effect of Tapering on Morphology and Interfacial Behavior of Diblock Copolymers from Molecular Dynamics Simulations

Tapered diblock copolymers are AB diblock copolymers modified by adding a gradient region between the blocks in which composition varies smoothly from one species to the other. This gives additional control parameters, the length of the taper and its direction, to control the microphase separation behavior. Using tapers can also increase the accessibility of the bicontinuous gyroid phase, potentially of interest in transport applications. Recently, the phase diagram of these systems was predicted using self-consistent field theory (SCFT). Here, we perform coarse-grained molecular dynamics (MD) simulations to investigate both the structural and dynamic properties of tapered diblock copolymers. The MD results are consistent with the SCFT phase diagram, and the density profiles are also similar as a function of taper length and direction. We additionally compute mean-squared displacements and end-to-end relaxation times of lamellar systems and observe individual polymer conformations. Increasing taper length effectively lowers segregation strength and leads to a smaller domain spacing; the changes in dynamics are also discussed. The short (30%) inverse taper has a significantly shorter domain spacing than the diblock and qualitatively different polymer conformations (chains can fold back and forth across the interface).
Authors:
 [1] ;  [1] ;  [1]
  1. The Ohio State Univ., Columbus, OH (United States). William G. Lowrie Dept. of Chemical and Biomolecular Engineering
Publication Date:
Grant/Contract Number:
SC0014458; 1454343
Type:
Accepted Manuscript
Journal Name:
Macromolecules
Additional Journal Information:
Journal Volume: 48; Journal Issue: 14; Journal ID: ISSN 0024-9297
Publisher:
American Chemical Society
Research Org:
The Ohio State Univ., Columbus, OH (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Science Foundation (NSF)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
OSTI Identifier:
1468593

Seo, Youngmi, Brown, Jonathan R., and Hall, Lisa M.. Effect of Tapering on Morphology and Interfacial Behavior of Diblock Copolymers from Molecular Dynamics Simulations. United States: N. p., Web. doi:10.1021/ma502309h.
Seo, Youngmi, Brown, Jonathan R., & Hall, Lisa M.. Effect of Tapering on Morphology and Interfacial Behavior of Diblock Copolymers from Molecular Dynamics Simulations. United States. doi:10.1021/ma502309h.
Seo, Youngmi, Brown, Jonathan R., and Hall, Lisa M.. 2015. "Effect of Tapering on Morphology and Interfacial Behavior of Diblock Copolymers from Molecular Dynamics Simulations". United States. doi:10.1021/ma502309h. https://www.osti.gov/servlets/purl/1468593.
@article{osti_1468593,
title = {Effect of Tapering on Morphology and Interfacial Behavior of Diblock Copolymers from Molecular Dynamics Simulations},
author = {Seo, Youngmi and Brown, Jonathan R. and Hall, Lisa M.},
abstractNote = {Tapered diblock copolymers are AB diblock copolymers modified by adding a gradient region between the blocks in which composition varies smoothly from one species to the other. This gives additional control parameters, the length of the taper and its direction, to control the microphase separation behavior. Using tapers can also increase the accessibility of the bicontinuous gyroid phase, potentially of interest in transport applications. Recently, the phase diagram of these systems was predicted using self-consistent field theory (SCFT). Here, we perform coarse-grained molecular dynamics (MD) simulations to investigate both the structural and dynamic properties of tapered diblock copolymers. The MD results are consistent with the SCFT phase diagram, and the density profiles are also similar as a function of taper length and direction. We additionally compute mean-squared displacements and end-to-end relaxation times of lamellar systems and observe individual polymer conformations. Increasing taper length effectively lowers segregation strength and leads to a smaller domain spacing; the changes in dynamics are also discussed. The short (30%) inverse taper has a significantly shorter domain spacing than the diblock and qualitatively different polymer conformations (chains can fold back and forth across the interface).},
doi = {10.1021/ma502309h},
journal = {Macromolecules},
number = 14,
volume = 48,
place = {United States},
year = {2015},
month = {7}
}