Flow Fields Controlled Structuring of Ionizable Polymers

PI Gary S. Grest, Sandia National Laboratories
Co-PI Dvora Perahia, Clemson University
Stan Moore, Sandia National Laboratories
Grest INCITE image

Visualization of the polymer backbone of polystyrene sulfonate with sulfonation fraction f after an elongation strain ε = 10 for strain rate ε̇ = 108 s −1 . Chains are colored according to their end-to-end distance R. Credit: S. S. Mohottalalage et al., Macromolecules 56, 947 (2023)


Project Summary

Using high performance computations, this project will determine the physics that controls giant molecules (polymers) that consist of several distinct chemical blocks, and the process by which these molecules can be transformed into viable materials for new uses including clean energy and biomedical technologies.

Project Description

Polymers are ubiquitous in modern life and are the cornerstone of numerous technologies. Nevertheless, the same properties that drive their uses pose a challenge to their assembly into viable materials. Full realization of their potential requires control over the collective motion of macromolecules in highly inhomogeneous large systems, that are often processed into viable materials under flow. Though pathways for processing of macromolecules have been developed, achieving sub-molecular control over their structure and response remains highly desired, and presents a key challenge to the design and manufacturing of smart responsive polymeric materials. 

This work will use exascale computing to determine the fundamental response of structured ionizable polymers for energy applications, to flow. The research will elucidate new physics concepts that quantify the interrelation of responses across length scales, from atomistic to macroscopic, impacting processing and upcycling of a technologically important class of materials. Using fully atomistic classical molecular dynamics simulations, the project will generate compute-polymeric systems of structured ionizable block co-polymers, comparable in molecular weights to polymers measured in neutron scattering experiments. The structure and dynamics of these materials in their quiescent state will first be resolved, followed by nonequilibrium studies of these systems under flow. The understanding of the quiescent polymers will provide fundamental insight into their structure and dynamics that will be correlated with their response to flow. 

The projected results will correlate the structure and dynamics of distinctive segments of structured polymers including their ionic blocks and non-ionic blocks in their quiescent state and under flow with the resulting macroscopic properties. These results will answer a fundamental polymer physics challenge of understanding the collective response of inhomogeneous systems controlled by distinctive energy length scales, while contributing directly to enhancing processing conditions of polymers for energy applications