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Title: Influence of Hydrophobicity on Polyelectrolyte Complexation

Abstract

Polyelectrolyte complexes are a fascinating class of soft materials that can span the full spectrum of mechanical properties from low viscosity fluids to glassy solids. This spectrum can be accessed by modulating the extent of electrostatic association in these complexes. However, to realize the full potential of polyelectrolyte complexes as functional materials their molecular level details need to be clearly correlated with their mechanical response. The present work demonstrates that by making simple amendments to the chain architecture it is possible to affect the salt responsiveness of polyelectrolyte complexes in a systematic manner. This is achieved by quaternizing poly(4-vinylpyridine) (QVP) with methyl, ethyl and propyl substituents– thereby increasing the hydrophobicity with increasing side chain length– and complexing them with a common anionic polyelectrolyte, poly(styrene sulfonate). The mechanical 1 ACS Paragon Plus Environment behavior of these complexes is compared to the more hydrophilic system of poly(styrene sulfonate) and poly(diallyldimethylammonium) by quantifying the swelling behavior in response to salt stimuli. More hydrophobic complexes are found to be more resistant to doping by salt, yet the mechanical properties of the complex remain contingent on the overall swelling ratio of the complex itself, following near universal swelling-modulus master curves that are quantified in thismore » work. The rheological behavior of QVP complex coacervates are found to be approximately the same, only requiring higher salt concentrations to overcome strong hydrophobic interactions, demonstrating that hydrophobicity can be used as an important parameter for tuning the stability of polyelectrolyte complexes in general, while still preserving the ability to be processed “saloplastically”.« less

Authors:
ORCiD logo [1];  [1]; ORCiD logo [1]; ORCiD logo [2];  [3]; ORCiD logo [1]
  1. Department of Materials Science &, Engineering, Northwestern University, Evanston, Illinois 60208, United States
  2. Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
  3. X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, United States
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Institute of Standards and Technology (NIST) - Center for Hierarchical Materials Design (CHiMaD)
OSTI Identifier:
1421981
DOE Contract Number:
AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Macromolecules; Journal Volume: 50; Journal Issue: 23
Country of Publication:
United States
Language:
English

Citation Formats

Sadman, Kazi, Wang, Qifeng, Chen, Yaoyao, Keshavarz, Bavand, Jiang, Zhang, and Shull, Kenneth R. Influence of Hydrophobicity on Polyelectrolyte Complexation. United States: N. p., 2017. Web. doi:10.1021/acs.macromol.7b02031.
Sadman, Kazi, Wang, Qifeng, Chen, Yaoyao, Keshavarz, Bavand, Jiang, Zhang, & Shull, Kenneth R. Influence of Hydrophobicity on Polyelectrolyte Complexation. United States. doi:10.1021/acs.macromol.7b02031.
Sadman, Kazi, Wang, Qifeng, Chen, Yaoyao, Keshavarz, Bavand, Jiang, Zhang, and Shull, Kenneth R. Thu . "Influence of Hydrophobicity on Polyelectrolyte Complexation". United States. doi:10.1021/acs.macromol.7b02031.
@article{osti_1421981,
title = {Influence of Hydrophobicity on Polyelectrolyte Complexation},
author = {Sadman, Kazi and Wang, Qifeng and Chen, Yaoyao and Keshavarz, Bavand and Jiang, Zhang and Shull, Kenneth R.},
abstractNote = {Polyelectrolyte complexes are a fascinating class of soft materials that can span the full spectrum of mechanical properties from low viscosity fluids to glassy solids. This spectrum can be accessed by modulating the extent of electrostatic association in these complexes. However, to realize the full potential of polyelectrolyte complexes as functional materials their molecular level details need to be clearly correlated with their mechanical response. The present work demonstrates that by making simple amendments to the chain architecture it is possible to affect the salt responsiveness of polyelectrolyte complexes in a systematic manner. This is achieved by quaternizing poly(4-vinylpyridine) (QVP) with methyl, ethyl and propyl substituents– thereby increasing the hydrophobicity with increasing side chain length– and complexing them with a common anionic polyelectrolyte, poly(styrene sulfonate). The mechanical 1 ACS Paragon Plus Environment behavior of these complexes is compared to the more hydrophilic system of poly(styrene sulfonate) and poly(diallyldimethylammonium) by quantifying the swelling behavior in response to salt stimuli. More hydrophobic complexes are found to be more resistant to doping by salt, yet the mechanical properties of the complex remain contingent on the overall swelling ratio of the complex itself, following near universal swelling-modulus master curves that are quantified in this work. The rheological behavior of QVP complex coacervates are found to be approximately the same, only requiring higher salt concentrations to overcome strong hydrophobic interactions, demonstrating that hydrophobicity can be used as an important parameter for tuning the stability of polyelectrolyte complexes in general, while still preserving the ability to be processed “saloplastically”.},
doi = {10.1021/acs.macromol.7b02031},
journal = {Macromolecules},
number = 23,
volume = 50,
place = {United States},
year = {Thu Nov 16 00:00:00 EST 2017},
month = {Thu Nov 16 00:00:00 EST 2017}
}