Polymer Science Commons^™

Interfacial Phenomena Of Plastics: From Surface Modifications To Environmental Impacts, Kennedy Guillot

LSU Doctoral Dissertations

Plastic is a ubiquitous part of everyday life since its introduction in the previous century. Global production continues to exponentially increase, establishing plastics as one of the most dominant materials in modern manufacturing. Within the scope of academia, plastic is essential due to its low cost and sterility, particularly for minimizing contamination. Beyond the laboratory, plastic use spans numerous industries, and its use and disposal has since raised many environmental concerns. Once valued for its durability, plastics now pollute the environment in landfills and natural ecosystems. In recent decades, the consequences of this pollution have been investigated, yet the full …

Precision Bottlebrush Polymers: Synthesis, Characterization, And Structure-Property Relationship, Nduka D. Ogbonna

LSU Doctoral Dissertations

Bottlebrush polymers, a type of non-linear polymer characterized by densely grafted side chains on a linear backbone, offer a versatile platform for material design due to their unique thermomechanical and rheological behavior. Addressing the grand challenge of achieving structural precision for bottlebrush polymers remains crucial because traditional disperse mixtures are plagued with batch variability, limiting our ability to control their functions, and correlate theoretical predictions with experiments. To date, narrow-dispersity bottlebrush polymers remain highly heterogeneous, as they are typically synthesized from disperse linear building blocks.

To address this longstanding challenge of structural heterogeneity in brush polymers, the primary objective of …

Research On 3d Printing Resin Exposure Properties And Its Application On Centrifugal Microfluidic Platform Based On Fluorescence Detection, Zheng Qiao

LSU Doctoral Dissertations

This dissertation encapsulates significant advancements in the field of SLA 3D printing and centrifugal microfluidics. Central to the research is the development of a novel mathematical model for predicting trapped resin thickness in SLA 3D printing, a groundbreaking contribution that addresses a critical aspect of printing intricate structures. This model, the first to establish a mathematical relationship for resin thickness, is rooted in a comprehensive study of the resin curing process. The research leverages the concept of 'critical dosage' for resin curing, leading to a more refined and theoretically grounded approach for calculating curing thickness. Experimentation further validates the model, …

Thermal Frontal Polymerization – Applications In Coatings And Composites, Maria Martinez

LSU Doctoral Dissertations

Thermal frontal polymerization has long been used as a method to cure composites and coatings. However, this is the first time these applications have been used without the use of a catalyst, for the case of composites and coatings.

Chapter 2 discusses how to optimize cure-on-demand, thin layer coatings, using frontal polymerization. Previously, for the use of curing thin layer coating using thermal FP, it was known to just make the formulation viscous enough, as this would prevent premature quenching caused by heat loss. It was discovered that for a given layer thickness, a minimum viscosity and initiator concentration were …

Tuning Electrochemical Interactions And Polymer Electrolyte Interfaces For Enhanced Organic Acid Separations Using Electrodeionization, Matthew Leo Jordan

LSU Doctoral Dissertations

Chemical separations are critical processes for chemical and industrial plants to purify and isolate products however current separation technologies, such as distillation, rely on energy intensive processes. Electrochemical separation processes, such as electrodialysis and electrodeionization, are an energy efficient alternative that are emerging as an alternative for thermal-based separations. Organic acids are weakly ionizable species and susceptible for purification from process streams using electrochemical processes. Recently the fermentation route has garnered greater attention as a means for producing value-added chemicals, such as organic acids, from a renewable feedstock and aiding the circular economy. Some of the challenges electrodialysis faces for …

High Temperature Polymer Electrolytes For Hydrogen Fuel Cells And Electrochemical Pumps, Gokul Venugopalan

LSU Doctoral Dissertations

Hydrogen fuel cell and separation technologies such as proton exchange membrane fuel cells (PEMFCs) and electrochemical hydrogen pump (ECHP) offer a profound advantage in the transition to a low-carbon economy. An imperative hitch in hydrogen fuel cells and ECHP technology has been the electrocatalyst poisoning by carbon monoxide (CO) and other contaminants in the reactant mixture. By operating, hydrogen fuel cells and ECHPs at high temperatures (>200 °C), the effect of CO adsorption on the electrocatalyst surface could be curtailed. The high-temperature operation of devices necessitates a proton exchange membrane (PEM) to operate under anhydrous conditions.

In this work, …

Engineering Ionomer Materials For Addressing Ohmic Resistances In Electrochemical Desalination And Waste Heat Recovery, Varada Menon Palakkal

LSU Doctoral Dissertations

Water scarcity and energy availability present important challenges that need to be addressed in the coming centuries. In the front of water technologies, desalting brackish water is of extreme importance for thermal electric power plants, chemical manufacturing plants, and other industrial operations that treat and reuse their water utilities. Membrane capacitive deionization (MCDI) is an energy efficient desalination technique that has drawn attention from commercial entities. Most material research studies on MCDI focus on enhancing electrode performance while little emphasis is given to rationale design of ion-exchange membranes (IEMs). In this work, the ionic conductivity, permselectivity, and thickness for three …

A Model-Based Framework For The Smart Manufacturing Of Polymers, Santiago D. Salas Ortiz

LSU Doctoral Dissertations

It is hard to point a daily activity in which polymeric materials or plastics are not involved. The synthesis of polymers occurs by reacting small molecules together to form, under certain conditions, long molecules. In polymer synthesis, it is mandatory to assure uniformity between batches, high-quality of end-products, efficiency, minimum environmental impact, and safety. It remains as a major challenge the establishment of operational conditions capable of achieving all objectives together. In this dissertation, different model-centric strategies are combined, assessed, and tested for two polymerization systems.

The first system is the synthesis of polyacrylamide in aqueous solution using potassium persulfate …