RII Track-4:NSF: Atomic-Scale Understanding of the Self-Healing Mechanisms of Ionic Polymers

University Of Vermont & State Agricultural College, Burlington VT

Investigators

Abstract

Plastic pollution has become one of the most pressing environmental issues facing society due to the growing usage of disposable plastics. Developing sturdy and recyclable substitutes for single-use plastics will significantly reduce plastic waste. One way to reduce plastic waste is to develop self-healing ionic polymers that are resistant to permanent damage. Despite a massive amount of effort devoted to self-healing ionic polymer studies, the main mechanisms that yield optimal self-healing performance remain obscure. The goal of this fellowship is to provide an atomic-scale understanding of the self-healing mechanisms of ionic polymers. This aim will be achieved via a highly accurate large-scale accelerated molecular dynamics simulation technique developed at the host lab, Oak Ridge National Laboratory. Such a technique will allow the PI and her graduate and undergraduate students to closely examine the interaction of ionic polymers to acquire a complete understanding of their self-healing process while also enhancing the research capabilities of the PI’s lab. Research concepts will be then delivered to a broader audience by incorporating research outcomes to the PI's undergraduate materials science class and communicating to the younger generation through public outreach programs. Results from this fellowship project will be published in journal articles and conferences, which will expand the public's awareness of the University of Vermont and enhance the university’s reputation. This fellowship will also strengthen the connection between the University of Vermont and Oak Ridge National Laboratory and will incite potential new collaborations between the two institutions in the future. The overarching goal of this proposal is to obtain a clear and holistic atomic-scale understanding of the self-healing mechanisms of ionic polymers, aimed to enhance their self-healing performance. To achieve this overarching goal, the PI will establish a clear relationship between polymer and ion compositions and their self-healing performance based on atomistic modeling of polymer structure and dynamics. Atomic interactions and reactive dynamics will be investigated via an accurate and efficient methodology, i.e., the linear-scaling fragment molecular orbital (FMO) method based on long-range corrected (LC) density-functional tight-binding (DFTB) theory, which is highly suitable for studying ionic polymers. The physics-based understanding of the self-healing mechanisms for different ionic polymer compositions will accelerate high-performance materials selection, synthesis, and manufacturing for sustainable applications. As a byproduct, the dynamic information obtained via the FMO-LC-DFTB molecular dynamics simulations can be used to analyze their ionic transport properties, which are also of particular interest in flexible electronics. This proposed work will expand the PI’s scope of knowledge and skillset across various disciplines and will stimulate the research competitiveness in materials science studies at the University of Vermont. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.