Scatena, LawrenceTran, Emma2022-10-042022-10-042022-10-04https://hdl.handle.net/1794/27606Interfaces are ubiquitous and diverse in nature, as are surface-active molecules that self-assemble at interfaces. Surfactants and polymers are often found at various interfaces due to their interfacial properties. Such properties can be tuned by the chemical environment and make-up of the interface. For example, the behavior and functionality of surfactants may vary across a solid/liquid, air/liquid, and liquid/liquid interface. The works of this dissertation focuses on the oil/water interface, specifically the surface of oil-in-water nanoemulsions. Nanoemulsions are kinetically stable oil droplets dispersed in water that are 100s of nanometers in diameter. They are stabilized by various types and combinations of surfactants and polymers. From an application standpoint, nanoemulsions are prevalent in cosmetics, food science, drug delivery, and environmental remediation. The droplet surface is a common feature amongst a wide variety of these applications. Thus, emphasis has been placed on understanding how to control and tune droplet stability and interfacial properties. The studies detailed herein employs a novel surface-specific spectroscopy called vibrational sum frequency scattering spectroscopy to develop molecular-level insights into the self-assembly of surfactants and polymers to nanoemulsion surfaces. Dynamic light scattering, interfacial tensiometry, and zeta-potential measurements are utilized concurrently to complement molecular-level details with results reporting on the macroscopic properties of the system. The adsorption behavior and conformational arrangement of surfactants and polymers to the droplet surface contributes significantly to colloidal stability and interfacial properties. Specifically, the chemical environment, constituents of the adsorbed species, polymer layering behavior, and surface charge are important details that influence nanoemulsion properties. This kind of knowledge on interfacial phenomena and colloidal chemistry aids in the advancement of technological, commercial, and industrial applications involving emulsions. This dissertation contains published and unpublished co-authored material.en-USAll Rights Reserved.Electronic Thesis or Dissertation