Phase Behavior of a Single Structured Ionomer Chain in Solution

Journal Article · 14 August 2014 · Macromolecular Theory and Simulations

DOI: https://doi.org/10.1002/mats.201400046 · OSTI ID:1182990

Aryal, Dipak ^[1]; Etampawala, Thusitha ^[1]; Perahia, Dvora ^[1]; Grest, Gary S. ^[2]

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1. Clemson Univ., SC (United States). Dept. of Chemistry
2. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

Structured polymers offer a means to tailor transport pathways within mechanically stable manifolds. Here we examine the building block of such a membrane, namely a single large pentablock co-polymer that consist of a center block of a randomly sulfonated polystyrene, designed for transport, tethered to poly-ethylene-r-propylene and end-capped by poly-t-butyl styrene, for mechanical stability,using molecular dynamics simulations. The polymer structure in a cyclohexane-heptane mixture, a technologically viable solvent, and in water, a poor solvent for all segments and a ubiquitous substance is extracted. In all solvents the pentablock collapsed into nearly spherical aggregates where the ionic block is segregated. In hydrophobic solvents, the ionic block resides in the center, surrounded by swollen intermix of flexible and end blocks. In water all blocks are collapsed with the sulfonated block residing on the surface. Our results demonstrate that solvents drive different local nano-segregation, providing a gateway to assemble membranes with controlled topology.

• Research Organization: Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: AC04-94AL85000
• OSTI ID: 1182990
• Report Number(s): SAND-2014-15452J; 533843
• Journal Information: Macromolecular Theory and Simulations, Vol. 23, Issue 9; ISSN 1022-1344
• Publisher: WileyCopyright Statement
• Country of Publication: United States
• Language: English