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Title: Controlling domain orientation of liquid crystalline block copolymer in thin films through tuning mesogenic chemical structures

Abstract

Controlling the macroscopic orientation of nanoscale periodic structures of amphiphilic liquid crystalline block copolymers (LC BCPs) is important to a variety of technical applications (e.g., lithium conducting polymer electrolytes). To study LC BCP domain orientation, a series of LC BCPs containing a poly(ethylene oxide) (PEO) block as a conventional hydrophilic coil block and LC blocks containing azobenzene mesogens is designed and synthesized. LC ordering in thin films of the BCP leads to the formation of highly ordered, microphase-separated nanostructures, with hexagonally arranged PEO cylinders. Substitution on the tail of the azobenzene mesogen is shown to control the orientation of the PEO cylinders. When the substitution on the mesogenic tails is an alkyl chain, the PEO cylinders have a perpendicular orientation to the substrate surface, provided the thin film is above a critical thickness value. In contrast, when the substitution on the mesogenic tails has an ether group the PEO cylinders assemble parallel to the substrate surface regardless of the film thickness value.

Authors:
 [1];  [1];  [1];  [1];  [2];  [3]
  1. Institute for Molecular Engineering, The University of Chicago, Chicago Illinois 60637
  2. Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge Louisiana 70803 USA
  3. Institute for Molecular Engineering, The University of Chicago, Chicago Illinois 60637; Materials Science Division, Argonne National Laboratory, Argonne Illinois 60439
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science - Office of Basic Energy Sciences - Materials Sciences and Engineering Division; University of Chicago - Materials Research Science & Engineering Center (MRSEC)
OSTI Identifier:
1352820
DOE Contract Number:
AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Polymer Science. Part B, Polymer Physics; Journal Volume: 55; Journal Issue: 6
Country of Publication:
United States
Language:
English
Subject:
azobenzene mesogen; block copolymers; domain orientation; liquidcrystalline polymers; microphase separation; poly(ethylene oxide); self-assembly

Citation Formats

Xie, He-Lou, Li, Xiao, Ren, Jiaxing, Bishop, Camille, Arges, Christopher G., and Nealey, Paul F. Controlling domain orientation of liquid crystalline block copolymer in thin films through tuning mesogenic chemical structures. United States: N. p., 2017. Web. doi:10.1002/polb.24302.
Xie, He-Lou, Li, Xiao, Ren, Jiaxing, Bishop, Camille, Arges, Christopher G., & Nealey, Paul F. Controlling domain orientation of liquid crystalline block copolymer in thin films through tuning mesogenic chemical structures. United States. doi:10.1002/polb.24302.
Xie, He-Lou, Li, Xiao, Ren, Jiaxing, Bishop, Camille, Arges, Christopher G., and Nealey, Paul F. Tue . "Controlling domain orientation of liquid crystalline block copolymer in thin films through tuning mesogenic chemical structures". United States. doi:10.1002/polb.24302.
@article{osti_1352820,
title = {Controlling domain orientation of liquid crystalline block copolymer in thin films through tuning mesogenic chemical structures},
author = {Xie, He-Lou and Li, Xiao and Ren, Jiaxing and Bishop, Camille and Arges, Christopher G. and Nealey, Paul F.},
abstractNote = {Controlling the macroscopic orientation of nanoscale periodic structures of amphiphilic liquid crystalline block copolymers (LC BCPs) is important to a variety of technical applications (e.g., lithium conducting polymer electrolytes). To study LC BCP domain orientation, a series of LC BCPs containing a poly(ethylene oxide) (PEO) block as a conventional hydrophilic coil block and LC blocks containing azobenzene mesogens is designed and synthesized. LC ordering in thin films of the BCP leads to the formation of highly ordered, microphase-separated nanostructures, with hexagonally arranged PEO cylinders. Substitution on the tail of the azobenzene mesogen is shown to control the orientation of the PEO cylinders. When the substitution on the mesogenic tails is an alkyl chain, the PEO cylinders have a perpendicular orientation to the substrate surface, provided the thin film is above a critical thickness value. In contrast, when the substitution on the mesogenic tails has an ether group the PEO cylinders assemble parallel to the substrate surface regardless of the film thickness value.},
doi = {10.1002/polb.24302},
journal = {Journal of Polymer Science. Part B, Polymer Physics},
number = 6,
volume = 55,
place = {United States},
year = {Tue Jan 24 00:00:00 EST 2017},
month = {Tue Jan 24 00:00:00 EST 2017}
}