Polymer and Organic Materials Commons^™

Carbon-Based Nanocomposite Membranes For Membrane Distillation: Progress, Problems And Future Prospects, Chhabilal Regmi, Yuwaraj K. Kshetri, S. Ranil Wickramasinghe

Chemical Engineering Faculty Publications and Presentations

The development of an ideal membrane for membrane distillation (MD) is of the utmost importance. Enhancing the efficiency of MD by adding nanoparticles to or onto a membrane’s surface has drawn considerable attention from the scientific community. It is crucial to thoroughly examine state-of-the-art nanomaterials-enabled MD membranes with desirable properties, as they greatly enhance the efficiency and reliability of the MD process. This, in turn, opens up opportunities for achieving a sustainable water–energy–environment nexus. By introducing carbon-based nanomaterials into the membrane’s structure, the membrane gains excellent separation abilities, resistance to various feed waters, and a longer lifespan. Additionally, the use …

Optimizing The Expression Of Polyethylene Terephtalate Hydrolase-Encoding Synthetic Gene In Escherichia Coli Arctic Express (De3), Jocelyn Nataniel, Maria Ulfah, Dini Achnafani, Niknik Nurhayati, Gabriela Christy Sabbathini, Sri Rezeki Wulandari, Abinawanto Abinawanto, Is Helianti

Makara Journal of Science

The waste of polyethylene terephthalate (PET) plastic waste in Indonesia is a pressing concern due to its slow degradation and potential environmental damage. One promising solution is to utilize polyethylene terephthalate hydrolase from Ideonella sakaiensis (IsPETase), an enzyme that specifically degrades PET. However, inducing the expression of IsPETase synthetic gene in Escherichia coli BL21 (DE3) has been challenging because much of it remains insoluble. This study aimed to express IsPETase in E. coli Arctic Express (DE3) and optimize the conditions to enhance its production. First, pET22b(+)pelB-IsPETase was inserted into E. coli Arctic Express (DE3). The …

Green Chemistry Design Of Epoxies From Biomass For Circular Economy, Kavya Ganesan

All Dissertations

The commercial epoxies market in automobiles has been growing mainly in terms of usage as automotive coatings and lightweight composite structures manufacturing. Most of these commercial epoxies are bisphenol-based. Bisphenol-based epoxies are a class of high-performance polymer materials that, when cured, yield thermosets with high mechanical, thermal and chemical resistance properties. Roughly, North America produces around 123 billion pounds of these epoxies which are used in various industrial applications like coatings, composites, structural parts, automotive, electronics, construction etc. These epoxies are mainly manufactured from bisphenol-A (BPA) and epichlorohydrin (EPH). These raw materials are sourced from fossil fuel resources and are …

Engineering Nanofibers: Laboratory Characterization, Microstructural Analysis, And Image Processing Insights, Sayed Ahmadreza Razian, Mohammad Arjomandi, Kaspars Maleckis

UNO Student Research and Creative Activity Fair

Polymer nanofibers have attracted high interest in a wide array of applications, including biomaterial scaffolding, textiles, sensors, reinforcement in composites, and filtration systems. Many of these applications combine nanofibers into non-woven fabrics for better properties and easier manipulation. The properties and performance of nanofiber-based fabrics are affected by various microstructure parameters, including fiber alignment, diameter, and gap sizes between the nanofibers. These structural parameters can be controlled by adjusting various process parameters during manufacturing process, but the exact process parameter-microstructure relationships vary depending on the polymer system and need to be studied individually. The goal of this study is to …

Sustainable Materials For Environment − Multifunctional Material Made From Dead Leaves And Nanostructured Materials For Antibiotic Degradation, Siyuan Fang

Dissertations, Master's Theses and Master's Reports

As environmental pollution from industrial processes and human activities continues to rise, finding efficient approaches to recycle waste materials and degrade persistent contaminants becomes increasingly critical. Dead leaves, an abundant but underutilized biomass, present an opportunity for creating value-added materials if their biocomponents can be preserved and transformed. Simultaneously, antibiotics such as tetracycline are widely found in water bodies but pose serious ecological and health risks, necessitating effective degradation methods. This dissertation addresses these challenges by leveraging natural and nanostructured materials to develop multifunctional products and advanced photocatalytic processes.

Chapter 3 of this dissertation addresses the challenge of converting waste …

Novel Membrane Materials For Nutrient Recovery From Nutrient-Rich Resources, Km Prottoy Shariar Piash

Graduate Theses, Dissertations, and Problem Reports (ETD)

Global demand for fertilizer production is expanding substantially to meet the food demand of an increasing world population. Anaerobic digestate (AD) of various centralized wastewater facilities contains substantial amounts of ammonium (NH₄⁺) (300-800 mg/L), potassium (K⁺) (13-120 mg/L), and phosphorus (P) (30-100 mg/L)- based nutrients. In addition to reducing energy costs and CO₂ emissions compared to conventional fertilizing raw material manufacturing, recovering nutrients from these waste streams could help mitigate problems such as eutrophication, which otherwise incurs billions of dollars losses to US economy annually. Apart from nutrients, wastewater streams also contain organic pollutants …

Schaeffler Icvd Coating Machine, Louis Mcgrath

Williams Honors College, Honors Research Projects

Chemical Vapor Deposition (CVD) is mutual technology used to deposit thin film through a gaseous phase by vaporizing the solid materials. This conventional process usually requires high thermal stability of the materials, which is not applicable for most of the polymeric materials. Therefore, a novel process, initiated Chemical Vapor Deposition (iCVD) is developed by introducing the gaseous monument and initiator to form the thin film in-situ. By adjusting the free-radical polymerization in the vapor phase, a variety of thin and uniform polymer films can be achieved. Depending on the chemistry, iCVD has many categories. This report explains the design …

Air-Jet Bioprinting Of Stem Cell-Encapsulated Alginate Micro-Droplets For Organoid Biomanufacturing, Mirabella B. Stump

Electronic Theses and Dissertations

Biomanufactured 3D-organoids show promise for modeling and treating various conditions, particularly insulin-dependent diabetes mellitus (type-1 diabetes). Pancreatic islet organoids serve as sustainable sources of insulin-producing β-cells, potentially restoring insulin regulation in patients and providing a long-term solution for diabetes. Hydrogel droplet printing is an emerging technique in regenerative medicine due to its advantageous tunability and biocompatibility; however, challenges of consistency, quality control, and scalability persist. To address these issues, we developed a novel air-jetting based droplet bioprinting system for the generation of monodispersed alginate micro-droplets. The objective of this project was to incorporate human induced pluripotent stem cells (hiPSCs) into …

Characterization Of Interlayer Laser Shock Peening During Fused Filament Fabrication Of Polylactic Acid (Pla), Fabien Denise

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

The field of additive manufacturing (AM) has gained a significant amount of popularity due to the increasing need for more sustainable manufacturing techniques and the adaptive development of complex product geometries. The problem is that AM parts routinely exhibit flaws or weaknesses that affect functionality or performance. Over the years, surface treatments have been developed to compensate certain flaws or weaknesses in manufactured products. Combining surface treatments with the modularity of additive manufacturing could lead to more adaptable and creative improvements of product functions in the future. The current work evaluates the feasibility of pursuing a new research axis in …

Cellulose Materials For Drug Delivery Applications, Reham Mohamed

Mechanical Engineering Theses

Non-healing wounds are a growing global public health concern due to inadequate or ineffective therapeutic products available. Cellulose-based biopolymers are attractive wound dressing materials due to their biocompatibility, biodegradability, non-toxicity, and cost-effectiveness. This study aims to design and fabricate solid dosage formulations using carboxymethyl cellulose (CMC) and ethyl cellulose (EC) to facilitate multi-stage releases of phenytoin (PHT) and tetracycline hydrochloride (TCH) from plain carriers, fibers/films composites, and layer-by-layer fiber composites. Results from in vitro drug release assays demonstrated a time-dependent release up to 8 hours from PHT-loaded EC fibers, while TCH-loaded CMC films exhibited a rapid release within 5 minutes. …

Investigating The Rheological Behavior Of A Simple Yield Stress Fluid Under Shear Flows, Francesco Accetta

Theses

Many soft materials display unique and complex rheological behavior characterized by a transition from a solid-like to a fluid-like state upon the application of a force that exceeds the threshold to flow, known as the yield stress. Yield stress fluids are found in a wide range of commonly encountered materials including microgels, emulsions, and foams, and have been widely studied by rheologists over the last several decades. Carbopol is a popular polymeric microgel system as it displays simple, non-thixotropic rheological behavior and is typically seen as an ideal yield stress fluid. Previous research has demonstrated the reproducible behavior of shear …

Carbon Fibers From Athabasca Oil-Sand Asphaltenes, Blake Reardon

All Theses

Carbon fibers possess ultra-high specific strength and modulus. Therefore, the material is popular in aerospace, automotive, and sports industries. Approximately 95% of all carbon fibers are spun from a high-cost precursor, polyacrylonitrile (PAN). There is a need for a cheaper grade of carbon fiber for low-cost applications because about half of carbon fiber cost is associated with precursor cost. A promising alternative to the high-cost PAN precursor is petroleum-based asphaltene. Asphaltenes are highly aromatic and have a high carbon content but lack the purity of the PAN precursor. Processes like the molten- sodium desulfurization upgrading have been used to harvest …

Characterization Of Mechanically Recycled Polylactic Acid (Pla) Filament For 3d-Printing By Evaluating Mechanical, Thermal, And Chemical Properties And Process Performance, Mahsa Shabani Samghabady

All Theses

Polylactic acid (PLA) is a biopolymer made from renewable resources such as sugar and corn. PLA filament is a popular material used in Fused Deposition Modeling (FDM) 3D-printing. While this material has many advantages, all the failed parts, support structures, rafts, nozzle tests, and the many prototype iterations during the 3D-printing process contribute to the plastic pollution and release of greenhouse gases. Although PLA is biodegradable, it can take years to degrade in landfills. Instead of throwing away PLA waste and buying new filaments, PLA can be recycled. Amongst the different recycling technologies, mechanical recycling is the most environmentally friendly. …

Development Of Novel Sensor Coating Methodology To Enable Understanding Of Fouling Mechanisms On Ion Exchange Membranes, Andrew Ulmer

Honors Theses

As populations expand and natural water resources are depleted, severe droughts and limited access to clean water have become an increased threat to areas across the world. Effective and economic water treatment methods such as electrodialysis (ED) are vital for combating these threats, especially in developing nations and secluded locations. Organic foulant adsorption on the surface of ion exchange membranes severely limits the capabilities of water desalination systems such as ED along with significantly increasing maintenance costs. Understanding characteristics such as the total amount and rate at which these foulants at specific concentrations adsorb and desorb to the membranes is …

Enhancing Compatibility And Mechanical Properties Of Natural Rubber Composites, Krisma Yessi Sianturi, Adam Febriyanto Nugraha, Belle Kristaura, Mochamad Chalid

Journal of Materials Exploration and Findings

Pure natural rubber (NR) exhibits low mechanical properties, necessitating the incorporation of additives like vulcanizing agents and fillers. Carbon black and silica, conventional fillers, are relatively expensive and not environmentally friendly. This study explores using Oil Palm Empty Fruit Bunch (OPEFB) fiber as an affordable, abundant, and biodegradable alternative filler for NR. However, compatibility issues arise between the nonpolar NR and the polar OPEFB fiber. A latex-starch hybrid coupling agent (CA (NR-St)) was added to the composite formulation to address this. NR, OPEFB fiber, and the coupling agent were mixed using an open roll mill with a 10 phr OPEFB …

Elucidating The Mechanical And Transport Properties Of Lignin-Based Hydrogel Composites, Nicholas Gregorich

All Dissertations

The use of lignin in the fabrication of soft composites has become an emerging area of research in polymer science and polymer chemistry. These lignin-based materials present numerous benefits, notably, a reduction in the use of petroleum-based precursor, improved structural benefits to otherwise soft host polymers, as well as the inherent antimicrobial and antioxidant properties of lignin, making it suitable for biomaterials. Herein, we present two chemical reaction pathways of incorporating lignin that was fractionated and cleaned using the Aqueous Lignin Purification with Hot Agents (ALPHA) process into poly(vinyl alcohol) (PVA) hydrogel composites for aqueous-based separations. By leveraging the ALPHA …

Lignin Copolymer Property Prediction Using Machine Learning, Collin Larsen

Chemical Engineering Undergraduate Honors Theses

Lignin, an abundant biopolymer, is a waste byproduct of the paper and pulp industry. Despite its renewable nature and potential applicability in various products, such as plastics and composites, the development of lignin-based materials has been impeded by the cumbersome, Edisonian process of trial and error. This research proposes a novel approach to forecasting the properties of lignin-based copolymers by utilizing a recurrent neural network (RNN) based on the Keras models previously created by Tao et al. Example units of modified lignin were synthesized via esterification and amination functional group modifications. To increase the efficiency and accuracy of the prediction …

Separation Of Organic Acids Through Direct Catalysis From Sugars, Katelyn Robinson

Chemical Engineering Undergraduate Honors Theses

Society relies on plastic products, whether they are single use or durable. A downside of plastic is that the most common type is a product of oil and oil is not only a limited resource but also a climate-damaging resource. Polylactic acid (PLA) is a bio-based, biodegradable plastic. However, the process of converting biomass to polylactic acid polymer has the largest environmental impact of the PLA production process, so alternative methods of conversion are needed (Moretti et al., 2021). The polylactic acid polymer can be made with lactic acid, which can be converted from glucose.

Poly(Ether Imide)S: Synthesis And Properties, Rachel Price

Honors College Theses

The synthesis of strong polymers is crucial to the creation of heat-resistant, durable, and mechanically useful plastics that we use every day. Poly(ether imide)s are used in applications such as food service, aerospace, automotive, and many more. This thesis will discuss the synthesis and properties of these plastics to help express a larger understanding of these polymers.

Hydrothermal Liquefaction Of Saccharina Latissima For The Production Of Biofuel, Mayokun A. Oke

Mechanical Engineering Theses

We performed hydrothermal liquefaction of brown macroalga (Saccharina latissima) in the presence of homogenous and heterogenous catalysts such as KOH, Na₂CO₃, Pd/C, HZSM-5, Ce/HZSM-5, and Ni/SiO₂-Al₂O₃ in hot compressed water, to investigate their effects on product yield and composition in the biocrude. To investigate hydrocarbon production, we used methanol as co-solvent (methanol-to-water 1/4 vol.%) and as the only liquefaction solvent. We carried out the experiments in a batch reactor at 330^oC and 120-130 bar, and varying temperature, algae-to-water ratio, residence time, and pretreatment method. The biocrude yields …

Hybrid Modeling For Electrochemical Systems, Luis Alejandro Briceno-Mena

LSU Doctoral Dissertations

The discovery of new materials like catalysts, polymeric films, and biomolecules, is driven by industrial needs such as improving reaction or separation selectivity, enhancing therapeutic effects on medical treatments, or reducing costs of replacement. However, deployment of these advances in industrial applications is often hindered by the lack of models needed for design and optimization. Due to the novelty of materials and devices, experimental data and first principles' knowledge are scarce, making it hard to build models either via data-driven or knowledge based approaches. In this context, a way to efficiently combine domain knowledge with data could provide a pathway …

Comparing Weathering Effects Of Ultraviolet And Xenon Arc Accelerated Aging On Polyvinyl Chloride, Collin Mcinnes

Williams Honors College, Honors Research Projects

As the ubiquitousness of polymers increases and begins seeing use in outdoor settings, the need to fully understand how these materials degrade is also necessary. This study aims to compare two known accelerated aging methods, namely an ultraviolet light chamber and a xenon arc light chamber, to understand what differences, if any, manifest in the mechanical, chemical, and cosmetic deterioration of polyvinyl chloride (PVC) after long-term exposure. The study utilizes Fourier-transform infrared spectroscopy, dynamic mechanical analysis, thermogravimetric analysis, and colorimetry analysis to determine the extent of degradation and potential discrepancies between the aging methods.

Constructing A Fine Dispersion And Chemical Interface Based On An Electrostatic Self-Assembly And Aqueous Phase Compound In Go/Sio2/Sbr Composites To Achieve High-Wear Resistance In Eco-Friendly Green Tires, Rui Zhang, Jiaye Li, Stephen Jerrams, Shui Hu, Shipeng Wen, Ligun Zhang

Articles

The hazard to the ecosystem caused by rubber microparticles generated from tire abrasion has been a constant concern. Therefore, to protect this ecosystem, the development of a tire tread with high abrasion resistance is especially significant. Herein, γ-aminopropyltriethoxysilane (APTES) was used to modify graphene oxide (GO) and silica (SiO2) to obtain GO and SiO2 with positive charges (NG and NS). Furthermore, NG and NS were electrostatically self-assembled by using maleic anhydride (MAH) hydrolysis, thereby obtaining composite particles (NG-NS) with “bridged structures”. Also, the NG-NS/styrene butadiene rubber (SBR) compounds possessing fine dispersion of NG-NS were prepared by the aqueous compounding method. …

Solid-State Shear Pulverization: A Comprehensive Study On Polymer Processing Technology From A Systematic Innovation Perspective, Tyler A. Will

Master’s Theses

Solid-state shear pulverization (SSSP) is a continuous and scalable processing technique that imposes mechanochemical changes in polymer-based materials. It has been shown to impart beneficial properties onto homopolymers or create copolymers and composites through continuous fragmentation and fusion. The unique technology employs cold temperature to keep the polymer in the solid state. This thesis investigates industrial polymer processing in the context of real-world applications. This thesis analyzes SSSP using an organized methodology called systematic innovation (SI). SI facilitates problem solving by assisting engineers in conducting root cause analysis around a material and studying the physical setup of the equipment.

This …

Temperature-Dependent Diffusion In Block Copolymer Organogels, Ridwana Bashar

Master’s Theses

Organogels are often considered for transport-based applications such as transdermal drug delivery vehicles and gel actuators due to their unique properties. Recent consideration of styrenic block copolymer based organogels’ application in transdermal drug delivery requires an extensive investigation of drug diffusion behavior through these gels to assess their applicability. Temperature is a major influencing parameter on diffusion. The goal of this research is to better understand the impact of temperature on diffusion in styrenic triblock copolymer organogels. To accomplish this goal, we focused on three specific objectives: (i) accurately measure the diffusivities of a solute – AOT reverse micelles – …

Beeswax Wraps As An Alternative To Single-Use Plastics, Sarah Skiver

Williams Honors College, Honors Research Projects

The project goal was to compare the food storage efficacy of sustainable beeswax wraps verses the single-use plastic methods of resealable plastic sandwich bags and plastic cling wrap. The goal was also to test the reusability of the beeswax wraps, as it is a key advantage of beeswax wraps that is advertised. The project purpose was to explore sustainable and eco-friendly alternatives to single use plastics, which are harmful to the environment in both their production and their disposal. Food spoilage was compared in beeswax wrap, plastic sandwich bags, and plastic cling wrap, and spoilage was also observed in a …

Structural Design And Application Of Polymeric Silicon Elastomers, Jacob Wyant

Williams Honors College, Honors Research Projects

The purpose of this project was to determine how the polymeric structure and mechanical properties of this elastomer are affected by the ratio between the polydimethylsiloxane macromolecular chains and the crosslinkers. These were determined via tensile and compression testing. Then, spiropyran was added to observe how this fluorescence and crosslinking agent affected the elastomer. Also, the elastomer’s fluorescent and icephobic nature were tested. The elastomers with a higher ratio of crosslinker to macromolecular chain could withstand higher tensile and compressive strains but failed at lower stresses than their counterparts with lower concentrations of crosslinkers. The elastomers were also found to …

Defining The Proper Operating Time For The Septa Extractor, Abigail Jones

Williams Honors College, Honors Research Projects

Anionic polymerizations are a common type of reaction used to produce synthetic rubber. During these reactions, it is necessary to charge initiators, modifiers, and other substances, through pressurized containers that are sealed with rubber septa. These septa prevent oxygen and moisture from entering the pressurized container, and the reactor, though they need to be cleaned before use to remove other impurities. Currently a glass Soxhlet Extractor is used to remove such impurities, and though effective, it has a limited capacity, so it has to run frequently. This limitation led to the commissioning of the Septa Extractor, which is an automated …

Anti-Freeze Double Network Hydrogels, William Gross

Williams Honors College, Honors Research Projects

Three polyethylene glycol (PEG) based crosslinkers with repeat unit nominal weights of 62.1, 200, and 400 g/mol in agar/PAM double network (DN) hydrogels were used to study the effect of different crosslinkers on thermal and mechanical properties. Using the one-pot synthesis method, hydrogels with the PEG crosslinkers or methylene-bis-acrylamide (MBAA) were made via sol-gel transition for formation of agar network, and photopolymerization of the PAM network using Irgacure 2959 as photo initiator. Tensile and compression tests were performed on as prepared, swollen, and swollen & cooled specimens of each hydrogel. Freezing time and thermal imaging were performed in -20 °C …

An Experimental Study On The Mechanical Properties And Chemical Composition Of Lcd 3d Printed Specimens, Sebastian Gomez

College of Graduate Studies: Theses & Dissertations

Additive manufacturing technologies have been enhanced throughout the years yet have surprised the manufacturing industry due to their high-end surface finish and dimensional accuracy. Different experiments have been done to identify a specific phenomenon known in the vat-polymerization field. Distortion and dimensional inaccuracy tend to affect the overall properties of the process, either physical or chemical. This approach allows the understanding of how the physical properties have been affected and how to study the chemical properties to avoid this type of phenomenon. The chemical reaction between polymer and UV light has been studied and experimented with to the point that …