Doctor of Philosophy, The Ohio State University, 2022, Chemistry

Study of intermediates are vitally important for discerning reaction pathways, given their existence in transition states before the final products are formed. On the other hand, high-throughput analysis has emerged as paramount experimental necessities for research and industrial applications. The ability to study transient intermediates in a high throughput manner using ultra-small sample volumes, outside of the mass spectrometer but under controlled experimental conditions, has even bigger potential to expand the current state-of-the-art analytical measurement. This dissertation achieves this major objective in analytical method development by using selected chemical system that have importance in organic reactions that involve short-lived and isobaric intermediates, direct biofluid analysis for enhanced sensitivity, and the capture and characterization of non-volatile and labile organo-metallic intermediates of importance in Li-ion battery. There are many strategies to partially overcome these challenges described above. However, mass spectrometry has gained particular attention due to its high sensitivity, inherent selectivity, and fast response time. The introduction of electrospray and desorption electrospray ionization techniques have allowed mass spectrometry to be used for the capture of transient reaction intermediates and high-throughput analysis. Novel spray-based techniques have been developed in this dissertation that facilitate the study of reaction mechanism, both under solvent and solvent-free experimental conditions, while also offering high-throughput capabilities and the use of ultra-small sample volumes. Overall, this dissertation presents creative design and development of three methodologies as discussed in six major chapters. Chapter 2 introduces droplet imbibition platform, wherein surface effect of microdroplet is exploited by physical deposition of analyte on the surface of microdroplet with no significant diffusion to the bulk of mi (open full item for complete abstract)

Committee: Abraham Badu-Tawiah (Advisor); Amanda Hummon (Committee Member); Zachary Schultz (Committee Member); David Nagib (Committee Member) Subjects: Analytical Chemistry; Chemistry

Doctor of Philosophy, Case Western Reserve University, 2019, Chemical Engineering

Polymerized High Internal Phase Emulsions (polyHIPEs) are highly porous polymeric foams with a variety of potential applications such as in filtration, as sorbent materials, or for tissue scaffolding. Since these foams are prepared through emulsion templating, important aspects in polyHIPE research and development include (but are not limited to) the control of the porous structure, understanding the influence of the structure on fluid transport properties and the exploration of new applications for polyHIPEs by tuning surface properties. In this work, three emulsification procedures were adopted for the purpose of controlling the structure of the HIPE template. These procedures include two methods of different combinations of simple shear flow and extensional shear flow as can be found in a propeller-mixer or syringe setups, as well as the application of a centrifugal field. The influence of the mixing configurations on the HIPE was investigated in terms of droplet size/distribution, flow properties, curing process, and structural and mechanical properties of the polyHIPE foams. Furthermore, two important transport phenomena important to many polyHIPE applications, namely Darcy's flow and capillary flow, were studied using polyHIPE foams 2 with controlled morphology and surface properties. By conducting a permeability study and a spontaneous imbibition dynamic study, the interconnecting void (window) size was identified as the dominant structural parameter for both flows. In the spontaneous imbibition study, the window size distribution was found to have a direct impact on fluid saturation. Besides the morphology effect, foam surface wettability was also controlled by coating with surfactant-dioctyl sulfosuccinate (AOT). A critical surfactant coating concentration was observed above which a significant improvement in the water wettability and absorption rate were achieved. Such a critical concentration corresponds to a monolayer surface coverage of the foam int (open full item for complete abstract)

Committee: Donald Feke (Committee Chair); Ica Manas-Zloczower (Committee Member); Jay Mann Jr (Committee Member); Uziel Landau (Committee Member); David Schiraldi (Committee Member) Subjects: Chemical Engineering; Polymers

Doctor of Philosophy, University of Akron, 2016, Chemical Engineering

Several studies have been published describing the corrosion inhibition effectiveness of surfactant admixtures by measuring the ability of surfactant molecules to physically adsorb onto metal surfaces. However, the effects of these admixtures have not been previously studied on coated metal surfaces to determine their corrosion inhibition mechanism. While corrosion protective coatings isolate exposed metal surfaces by forming a barrier between a substrate and the electrolyte, their performance is highly dependent on their interaction with their immediate environment. During the winter season in Snowbelt areas where chloride roadway deicers are greatly employed, coated metal surfaces in vehicles are constantly exposed to harsh and changing environments making them susceptible to failure. In order to extend the service life of these exposed coated surfaces, additional treatment by surfactant admixtures is regarded as an effective corrosion prevention strategy. In this work, the corrosion mechanism of surfactant admixtures on coated metal panels is evaluated by understanding the interaction of the liquid-solid interface. Despite the numerous mechanisms of inhibition behavior, it is hypothesized in this study that the contributions from inhibition solution systems create a protective layer over substrates by the formation of multi layers from aggregation or adsorption of surfactants. Furthermore, this study will help understand the relationship of the surface of corrosion protective coatings and the interaction with its environment. Electrochemical impedance spectroscopy (EIS) is applied to evaluate the corrosion performance of a high performance, low VOC, two component polyurethane enamel and a high performance UV-cured coating system on carbon steel alloy A36 under immersion testing of sodium chloride solutions of surfactant admixtures. This electrochemical technique permits the evaluation of the properties of the coating system by monitoring its degradation (open full item for complete abstract)

Committee: Chelsea Monty Dr. (Advisor); Scott Lillard Dr. (Committee Member); Gang Cheng Dr. (Committee Member); Christopher Miller Dr. (Committee Member); John Senko Dr. (Committee Member) Subjects: Automotive Materials; Chemical Engineering; Engineering; Materials Science; Physical Chemistry