Degree
Doctor of Philosophy (PhD)
Department
Chemistry
Document Type
Dissertation
Abstract
This dissertation aims to uncover the effect of coronal charge patterning on the structure of aqueous micellar assemblies of ionic, sequence-defined peptoid multiblock copolymers in dilute and semi-dilute regime. This work involves a multifaceted approach involving molecular dynamics (MD) simulations, contrast-variation small-angle neutron scattering (CVSANS), other analytical methods (DLS, TEM, etc.). Biomolecules such as polysaccharides and intrinsically disordered proteins use charge patterning to modulate their structure, dynamics, intra/inter-molecular interactions, and biological functions. The unique opportunity for tailored morphologies in synthetic polymer assemblies, tuned only by the charge sequence of molecularly equivalent chains, is attractive for many applications. Polypeptoids are N-substituted polyglycine backbones are structural biomimetics of polypeptides. The absence of backbone hydrogen bonding and stereogenic centers of peptoids results in flexible backbone conformations with a diminished propensity to form secondary structures. The backbone conformations and polymer interaction with solvents can be tailored by the chemical identity of N-substituents on peptoids. Therefore, peptoids are a well-suited platform to investigate the effect of sequence-encoded electrostatic interactions on the resulting micellar structures, intramicellar conformations, and self-assembly behavior in aqueous solutions due to the possibility of precisely controlling the number and positions of the ionizable monomers along the chains. The central hypothesis of this work is that sequence-defined electrostatic monomers encoded in the peptoid backbone dictate micelle structure and dynamics by balancing electrostatic repulsion, hydration, and interfacial energetics.
These studies underscore the critical role of charge patterning in shaping the structure and behavior of synthetic self-assemblies, providing design rules for advanced polymeric materials, and deepening our understanding of biomimetic nanostructure formation in aqueous media.
Date
7-28-2025
Recommended Citation
Tsai, Erin, "Chemical Design and Modulation of the Self-Assembly of Sequence-Defined Ionic Polypeptoids in Aqueous Solution: Investigating Micellar Structure and Polymer Conformations" (2025). LSU Doctoral Dissertations. 6896.
https://repository.lsu.edu/gradschool_dissertations/6896
Committee Chair
Zhang, Donghui
DOI
10.31390/gradschool_dissertations.6896