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Title: Effect of Nanoscale Morphology on the Conductivity of Polymerized Ionic Liquid Block Copolymers

Authors:
; ; ; ; ;  [1];  [2]
  1. Drexel
  2. (
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
NSFUNIVERSITYU.S. ARMY RESEARCH
OSTI Identifier:
1123951
Resource Type:
Journal Article
Resource Relation:
Journal Name: Macromolecules; Journal Volume: 44; Journal Issue: (14) ; 06, 2011
Country of Publication:
United States
Language:
ENGLISH

Citation Formats

Weber, Ryan L., Ye, Yuesheng, Schmitt, Andrew L., Banik, Steven M., Elabd, Yossef A., Mahanthappa, Mahesh K., and UW). Effect of Nanoscale Morphology on the Conductivity of Polymerized Ionic Liquid Block Copolymers. United States: N. p., 2014. Web. doi:10.1021/ma201067h.
Weber, Ryan L., Ye, Yuesheng, Schmitt, Andrew L., Banik, Steven M., Elabd, Yossef A., Mahanthappa, Mahesh K., & UW). Effect of Nanoscale Morphology on the Conductivity of Polymerized Ionic Liquid Block Copolymers. United States. doi:10.1021/ma201067h.
Weber, Ryan L., Ye, Yuesheng, Schmitt, Andrew L., Banik, Steven M., Elabd, Yossef A., Mahanthappa, Mahesh K., and UW). Wed . "Effect of Nanoscale Morphology on the Conductivity of Polymerized Ionic Liquid Block Copolymers". United States. doi:10.1021/ma201067h.
@article{osti_1123951,
title = {Effect of Nanoscale Morphology on the Conductivity of Polymerized Ionic Liquid Block Copolymers},
author = {Weber, Ryan L. and Ye, Yuesheng and Schmitt, Andrew L. and Banik, Steven M. and Elabd, Yossef A. and Mahanthappa, Mahesh K. and UW)},
abstractNote = {},
doi = {10.1021/ma201067h},
journal = {Macromolecules},
number = (14) ; 06, 2011,
volume = 44,
place = {United States},
year = {Wed Aug 06 00:00:00 EDT 2014},
month = {Wed Aug 06 00:00:00 EDT 2014}
}
  • We demonstrate a simple, yet effective, mixed-salt method to increase the room temperature ionic conductivity of lithium-doped block copolymer electrolyte membranes by suppressing the crystalline phases in the conducting block. We examined a mixed-salt system of LiClO{sub 4} and LiN(SO{sub 2}CF{sub 3}){sub 2} (LiTFSI) doped into a lamellae-forming poly(styrene-b-ethylene oxide) (PS-PEO) diblock copolymer. The domain spacings, morphologies, thermal behavior, and crystalline phases of salt-doped PS-PEO samples were characterized, and the ionic conductivities of block copolymer electrolytes were obtained through ac impedance measurements. Comparing the ionic conductivity profiles of salt-doped PS-PEO samples at different mixed-salt ratios and total salt concentrations, wemore » found that the ionic conductivity at room temperature can be improved by more than an order of magnitude when coinhibition of crystallite growth is promoted by the concerted behavior of the PEO:LiClO{sub 4} and PEO:LiTFSI phases. Additionally, we examined the influence of mixed-salt ratio and total salt concentration on copolymer energetics, and we found that the slope of the effective interaction parameter (x{sub eff}) vs salt concentration in our lamellae-forming PS-PEO system was lower than that reported for a cylinder-forming PS-PEO system due to the balance between chain stretching and salt segregation in the PEO domains.« less
  • We demonstrate a simple, yet effective, mixed-salt method to increase the room temperature ionic conductivity of lithium-doped block copolymer electrolyte membranes by suppressing the crystalline phases in the conducting block. We examined a mixed-salt system of LiClO{sub 4} and LiN(SO{sub 2}CF{sub 3}){sub 2} (LiTFSI) doped into a lamellae-forming poly(styrene-b-ethylene oxide) (PS-PEO) diblock copolymer. The domain spacings, morphologies, thermal behavior, and crystalline phases of salt-doped PS-PEO samples were characterized, and the ionic conductivities of block copolymer electrolytes were obtained through ac impedance measurements. Comparing the ionic conductivity profiles of salt-doped PS-PEO samples at different mixed-salt ratios and total salt concentrations, wemore » found that the ionic conductivity at room temperature can be improved by more than an order of magnitude when coinhibition of crystallite growth is promoted by the concerted behavior of the PEO:LiClO{sub 4} and PEO:LiTFSI phases. Additionally, we examined the influence of mixed-salt ratio and total salt concentration on copolymer energetics, and we found that the slope of the effective interaction parameter ({chi}{sub eff}) vs salt concentration in our lamellae-forming PS-PEO system was lower than that reported for a cylinder-forming PS-PEO system due to the balance between chain stretching and salt segregation in the PEO domains.« less
  • No abstract prepared.
  • Concentrated solutions of poly(styrene-b-ethylene oxide) (PS-PEO) diblock copolymers were prepared using the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [EMI][TFSI] as the solvent. The self-assembled microstructures adopted by the copolymer solutions have been characterized using small-angle X-ray scattering. Lyotropic mesophase transitions were observed, with a progression from hexagonally packed cylinders of PEO, to lamellae, to hexagonally packed cylinders of PS upon increasing [EMI][TFSI] content. The change in lamellar domain spacing with ionic liquid concentration was found to be comparable to that reported for other block copolymers in strongly selective solvents. The ionic conductivity of the concentrated PS-PEO/[EMI][TFSI] solutions was measured via impedance spectroscopy,more » and ranged from 1 x 10{sup -7} to 1 x 10{sup -3} S/cm at temperatures from 25-100 C. Additionally, the ionic conductivity of the solutions was found to increase with both ionic liquid concentration and molecular weight of the PEO blocks. The ionic conductivity of PEO homopolymer/[EMI][TFSI] solutions was also measured in order to compare the conductivity of the PS-PEO solutions to the expected limit for a lamellar sample with randomly oriented microstructure grains.« less