10.25394/PGS.12733070.v1
Jessica L Sargent
Jessica L
Sargent
Investigation of Ionically-Driven Structure-Property Relationships in Polyelectrolyte Networks
Purdue University Graduate School
2020
polymer chemistry
polymer physics
polyelectrolyte
hydrogel
Materials characterization
Materials chemistry
Materials Engineering not elsewhere classified
Polymers and Plastics
Functional Materials
Chemical Characterisation of Materials
Macromolecular and Materials Chemistry not elsewhere classified
Physical Chemistry of Materials
Synthesis of Materials
Condensed Matter Characterisation Technique Development
2020-07-29 20:08:21
Thesis
https://hammer.purdue.edu/articles/thesis/Investigation_of_Ionically-Driven_Structure-Property_Relationships_in_Polyelectrolyte_Networks/12733070
<div>Despite the abundant current applications for ionic hydrogels, much about the stimuli-responsive behavior of these materials remains poorly understood. Due to the soft nature of these materials, the number of traditional characterization methods which can be applied to these systems is limited. Many studies have been conducted to characterize bulk property responses of these materials, and experimental studies have been produced examining the distribution of free ions around single polyelectrolyte chains. However, little experimental work has been published in which molecular-scale interactions are elucidated in confined polyelectrolyte networks. Furthermore, the way in which responsive properties, other than bulk swelling capacity, scale with ionic fraction in mixed polyelectrolyte-non-polyelectrolyte hydrogel systems has not been thoroughly investigated.</div><div>The distribution and strength of polymer-counter-ion bonds has a remarkable effect on hydrogel properties such as absorption capacity, mechanical strength, and size and chemical selectivity. In order to tailor these properties for targeted applications in ionic environments, it is imperative that we thoroughly understand the character of these polymer-ion interactions and their arrangement within the bulk hydrogel. In order to do so, however, non-traditional methods of analysis must be employed.</div><div>This dissertation focuses on a model part-ionic hydrogel system, poly(sodium acrylate-co-acrylamide), in order to assess not only the polymer-counter-ion interactions but also the impact of gel ionic fraction on these interactions and the responses which they induce in gel performance properties. A model alkali (NaCl), alkaline earth (CaCl2), and transition (CuSO4) metal salt are employed to investigate changes in polymer properties from the macroscale to the nanoscale. The aim of this dissertation is to lay the foundation for the development of fundamental structure-property relationships by which we may fully understand the ionically-induced performance properties of polyelectrolyte networks.</div>