Off-campus UMass Amherst users: To download campus access dissertations, please use the following link to log into our proxy server with your UMass Amherst user name and password.

Non-UMass Amherst users: Please talk to your librarian about requesting this dissertation through interlibrary loan.

Dissertations that have an embargo placed on them will not be available to anyone until the embargo expires.

Author ORCID Identifier

https://orcid.org/0000-0002-2019-0599

AccessType

Campus-Only Access for One (1) Year

Document Type

dissertation

Degree Name

Doctor of Philosophy (PhD)

Degree Program

Chemistry

Year Degree Awarded

2021

Month Degree Awarded

September

First Advisor

Prof. Sankaran Thayumanavan

Subject Categories

Materials Chemistry | Organic Chemicals | Organic Chemistry | Polymer Chemistry

Abstract

Nature has designed magnificent responsive systems by constructing several interacting molecular level networks for the recognition and propagation of chemical and biochemical information. One of the eminent characteristics of these systems is their capability to quickly transduce molecular scale recognition events into macroscopic or visually observable responses. Inspired by these systems present in nature, we became interested in developing artificial responsive systems with similar capabilities. This dissertation will feature four such systems that employ amphiphilic oligomers and polymers which were chosen as the scaffolds because of their high thermodynamic stability, low critical aggregation concentrations, convenient handles to incorporate functional group modifications, and stimuli-responsive moieties. The first chapter utilizes the inherent self-assembly properties of liquid crystals that propagate over large length scales and therefore offer highly sensitive interfaces with a convenient optical readout. By monitoring the interactions and organization of various oligomers at the liquid crystal-aqueous interface, an investigation on the oligomer structure-property relationship was carried out. These transitions, which are sensitive to subtle structural changes of the oligomers, can be leveraged for sensing applications. The second chapter focuses on designing self-immolative polymers to develop polymeric nanoparticles, the interfaces of which can be triggered for destruction and molecular release. Here, we investigated the relative control over the kinetics of depolymerization and trigger-induced molecular release through two fundamentally different depolymerization pathways, chain unzipping versus chain scission. The study provides key insights into obtaining amplified responses through interfacial triggering based on polymers. The third chapter employs polymers to develop nanoparticles that activate inflammasome complexes and studied their structural features. We investigated plausible mechanistic pathways for inflammasome activations mediated by polymeric nanoparticles that lead to pyroptotic cell death. The fourth chapter focuses on studying the outcome of the non-covalent interactions between oligomeric self-assemblies and surfaces that are dictated by the energy of association and binding. Modulating these interactions provided us with deeper insights into the binding, deformation, disassembly, and controlled release of sequestered guests. All the four responsive systems described above can recognize molecular-scale events and provide us a macroscopic response via oligomeric and polymeric interfaces for sensing and controlled release applications.

DOI

https://doi.org/10.7275/22784433

Available for download on Thursday, September 01, 2022

Share

COinS