Interfacial Mechanics of Block Copolymers for the Development of Biological and Environmental Sensors
Author
Durkin, Tyler J.Issue Date
2024Keywords
Block copolymersInterfacial tension
Janus particles
Polymer modification
Sensing devices
Surfactants
Advisor
Savagatrup, Suchol
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The University of Arizona.Rights
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction, presentation (such as public display or performance) of protected items is prohibited except with permission of the author.Embargo
Release after 08/08/2025Abstract
Current methods in biological and environmental sensing, though highly selective to relevant analytes, typically require transport to a well-equipped laboratory for analysis and such analysis needs to be performed by highly trained professionals. A novel alternative to these methods is the active complex emulsion, which consists of a hydrocarbon oil and a fluorocarbon oil co-emulsified in an aqueous surfactant solution. These emulsions, which are highly tunable and responsive to their surrounding environment, if they are properly configured, have the potential to serve as the basis for a selective sensing device that can produce real-time results on-site. This dissertation explores the design of a successful recognition element for active complex emulsions based around a block copolymer surfactant. Chapter 1 consists of an introduction to the scope of the field and includes sections regarding emulsion formation and stabilization, surfactant properties and examples of common applications of molecular surfactants, a discussion on the various methods used to quantify interfacial tension, and a brief review of block copolymer surfactants and a comparison of their properties to common molecular surfactants. Chapter 2 discusses the importance of block copolymer (polystyrene-block-poly(acrylic acid) structure, composition, and conformation on the surfactant properties of the polymer. It also illustrates the modification process, the carbodiimide-mediated amidation, undertaken to imbue additional functionality into the polymeric surfactant and a proof-of-concept of a “on/off” mechanism in which the functionality of an immobilized polymer can be blocked through inversion of an active complex emulsion. Chapter 3 makes note of the development of a selective metal recognition element using a block copolymer functionalized with a metal chelator. Specifically, this polymer is shown to deconvolute the interference from various non-targeted metal ions. Appendix A contains a mini-review of the current state of the field of sensing devices for sepsis biomarkers. Appendix B is an overview of the emerging properties of various molecular surfactants upon interaction with other contaminants or each other in water supplies. Finally, Appendix C and Appendix D consist supporting documentation for Chapters 2 and 3, respectively.Type
Electronic Dissertationtext
Degree Name
Ph.D.Degree Level
doctoralDegree Program
Graduate CollegeChemical Engineering