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Title: Fluids density functional theory and initializing molecular dynamics simulations of block copolymers

Classical, fluids density functional theory (fDFT), which can predict the equilibrium density profiles of polymeric systems, and coarse-grained molecular dynamics (MD) simulations, which are often used to show both structure and dynamics of soft materials, can be implemented using very similar bead-based polymer models. We aim to use fDFT and MD in tandem to examine the same system from these two points of view and take advantage of the different features of each methodology. Additionally, the density profiles resulting from fDFT calculations can be used to initialize the MD simulations in a close to equilibrated structure, speeding up the simulations. Here in this paper, we show how this method can be applied to study microphase separated states of both typical diblock and tapered diblock copolymers in which there is a region with a gradient in composition placed between the pure blocks. Both methods, applied at constant pressure, predict a decrease in total density as segregation strength or the length of the tapered region is increased. The predictions for the density profiles from fDFT and MD are similar across materials with a wide range of interfacial widths.
Authors:
 [1] ;  [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:
SC0014209; 1454343
Type:
Accepted Manuscript
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 144; Journal Issue: 12; Journal ID: ISSN 0021-9606
Publisher:
American Institute of Physics (AIP)
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:
36 MATERIALS SCIENCE
OSTI Identifier:
1468778
Alternate Identifier(s):
OSTI ID: 1243353

Brown, Jonathan R., Seo, Youngmi, Maula, Tiara Ann D., and Hall, Lisa M.. Fluids density functional theory and initializing molecular dynamics simulations of block copolymers. United States: N. p., Web. doi:10.1063/1.4943982.
Brown, Jonathan R., Seo, Youngmi, Maula, Tiara Ann D., & Hall, Lisa M.. Fluids density functional theory and initializing molecular dynamics simulations of block copolymers. United States. doi:10.1063/1.4943982.
Brown, Jonathan R., Seo, Youngmi, Maula, Tiara Ann D., and Hall, Lisa M.. 2016. "Fluids density functional theory and initializing molecular dynamics simulations of block copolymers". United States. doi:10.1063/1.4943982. https://www.osti.gov/servlets/purl/1468778.
@article{osti_1468778,
title = {Fluids density functional theory and initializing molecular dynamics simulations of block copolymers},
author = {Brown, Jonathan R. and Seo, Youngmi and Maula, Tiara Ann D. and Hall, Lisa M.},
abstractNote = {Classical, fluids density functional theory (fDFT), which can predict the equilibrium density profiles of polymeric systems, and coarse-grained molecular dynamics (MD) simulations, which are often used to show both structure and dynamics of soft materials, can be implemented using very similar bead-based polymer models. We aim to use fDFT and MD in tandem to examine the same system from these two points of view and take advantage of the different features of each methodology. Additionally, the density profiles resulting from fDFT calculations can be used to initialize the MD simulations in a close to equilibrated structure, speeding up the simulations. Here in this paper, we show how this method can be applied to study microphase separated states of both typical diblock and tapered diblock copolymers in which there is a region with a gradient in composition placed between the pure blocks. Both methods, applied at constant pressure, predict a decrease in total density as segregation strength or the length of the tapered region is increased. The predictions for the density profiles from fDFT and MD are similar across materials with a wide range of interfacial widths.},
doi = {10.1063/1.4943982},
journal = {Journal of Chemical Physics},
number = 12,
volume = 144,
place = {United States},
year = {2016},
month = {3}
}