Date of Award
2025
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Materials Science
First Advisor
Jihong Ma
Abstract
Ionic liquid (IL) membranes synthesized from ionic polyamides (IPA) show promise as durable, self-repairing selective gas transport media. However, the nanoscale mech- anisms behind these materials’ functionalities are poorly understood. The chemi- cal composition of the polyamide backbone determines which intermolecular inter- actions may occur within the membrane and influence the membrane’s thermome- chanical properties. In particular, hydrogen bonds formed between highly polarized amide groups may contribute to the membrane’s properties as significantly as inter- actions between the IL’s primary charged components. This study used molecular dynamics simulations to compare the thermomechanical properties of two sets of IL polyamide membranes. The first set was capable of forming interpolymer hydrogen bonds through amide groups, while the second set was modified to prohibit such in- teractions. Experiments were run on each set of membranes to determine the effects of amide chain alignments on material properties including creep resistance, ionomer radii of gyration, and density. Additionally, each membrane’s ability to autonomously heal fractures over a 10ns period was tested. The experiments revealed a complex re- lationship between ionomer composition and material properties. Chain alignments yielded greater creep resistance below the glass transition temperature and higher pair distribution functions of oxygen-nitrogen pairs in the expected range of hydro- gen bonding. The membranes’ self-healing mechanisms proved to depend on ionomer composition, with chain alignments affecting the rate at which each membrane prop- erty was recovered.
Language
en
Number of Pages
146 p.
Recommended Citation
Buckser, Edward, "Molecular Dynamics Analyses of Self-Healing Ionic Polyamide Thermomechanical Properties" (2025). Graduate College Dissertations and Theses. 2047.
https://scholarworks.uvm.edu/graddis/2047