Chemical Engineering Commons^™

Manufacturing Of Aligned Electrospun Nanofiber Yarns For Their Enhanced Mechanical And Piezoelectric Properties, Adaugo Mary-Frances Enuka

Theses and Dissertations

Electrospinning is a widely used technique for producing nanofibers with diverse applications. This method uses polymer solutions and strong electric fields to generate nano-sized fibers with unique properties. This study presents a novel manufacturing approach that enables the production of electrospun poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofiber yarns using an automated parallel track system and an adjustable roll-to-roll collector. This research examines the impact of an automated post-drawing system on the polymer chain orientation, crystallinity, tensile strength, morphology, and piezoelectric properties of PVDF-HFP nanofiber yarn. The results reveal that the post-drawing process significantly improves molecular alignment, increases tensile strength, and enhances the …

Tuning Polymer Glass Formation Behavior And Understanding Time-Temperature Superposition Breakdown With Oligomeric Additives, Peijing Yue

USF Tampa Graduate Theses and Dissertations

The glass transition of polymer melts has been investigated for over a century. Even so, there are still many unanswered questions about the underlying physics. Countless theories were proposed to explain and define glass transition temperatures. More specifically, both the origins of the glass transition and underlying classification of glass as a state of matter remain unresolved. Time-temperature superposition (TTS) is one of the most widely used techniques to characterize the viscoelastic behavior of a material and the mechanical behavior and is employed to reduce the measuring time during characterization. Despite the widespread use of TTS, many authors have reported …

Investigating The Feasibility And Mechanisms Of Cold Spray Deposition Of Polymer-Based Powders On Fiber-Reinforced Composite Substrates, Nicholas Beau Mennie

Theses and Dissertations

Fiber-reinforced composites have become important structural components in industries such as aerospace and energy due to their high mechanical strength and relatively light structural weight. However, during operation, these materials can be prone to impact damage and disintegration. Effective protection via metalization and repair of composites would, therefore, reduce the cost and time for replacement parts. Polymer-based cold spray, while a relatively new technique, can be utilized to metalize and possibly repair composite materials subjected to impact-induced damage. In this work, studies involving polymers and composite cold spray were performed to enable the process of safeguarding, enhancing, or repairing various …

Copper-Based Electrocatalysts For Electrochemical Reduction Of Co2 To C2 Products, Monsuru Olatunji Dauda

LSU Master's Theses

The electrochemical reduction of CO₂ using copper-based electrocatalysts has emerged as a promising approach for sustainable chemical production, offering a pathway to mitigate the rising atmospheric CO₂ levels while generating valuable fuels and chemicals. However, the selectivity and efficiency of copper-based catalysts towards specific C₂ products remain a major challenge, hindering their commercial viability. This thesis focuses on the development, characterization, and mechanistic understanding of three promising electrocatalyst systems for multi-carbon product generation from CO₂ reduction: copper-phosphide (Cu-P), copper-tin (Cu-Sn), and copper selenide (Cu₂Se). A comprehensive investigation of the electrocatalysts was conducted using advanced …

Activity Descriptors As Tools For Designing Highly Efficient Electrocatalysts For Water Splitting, Aya Gomaa

Theses and Dissertations

There is an uprising urge to design efficient, active, and durable catalysts to achieve sustainable hydrogen production. The unambiguity of which material should be used pushed the scientific community to devote enormous efforts in exploring different elements with different ratios on trial and error bases. However, the bridge between the theoretical calculation and the experiments introduced a new realm of designing efficient catalysts by introducing the concept of activity descriptors. In the first part of the thesis, the ability to convert waste stainless steel (SS) 316L meshes into highly efficient and durable oxygen evolution reaction (OER) catalysts is demonstrated. The …

Use Of Nanoparticle Additives To Achieve Desirable Properties In Fluorine-Free Firefighting Foams, Annelise Kathleen Curtin

USF Tampa Graduate Theses and Dissertations

Class B Firefighting foams play a crucial role in protecting equipment and people fromliquid fuel fires but concerns regarding the impacts of per- and poly-fluoroalkyl substances (PFAS) have resulted in bans on the use of aqueous film forming foam (AFFF). Fluorine-free replacements are yet to achieve the same level of performance. Nanoparticles including silica and clay have been used to improve foam stability, especially in environments where hydrocarbon fuels are present. These materials have also been used in solid composites to improve fire resistance. The stability of aqueous foams containing silica and Laponite RD nanoparticles along with surfactants of different …

Department Chairs As Change Agents: A Virtual Cross-Institutional Professional Development Model For Chairs, Cinzia Cervato, Stephanie Peterson, Carrie Ann Johnson, Canan Bilen-Green, Carla Koretsky, Adrienne Minerick, Gul Okudan Kremer

Michigan Tech Publications

Department chairs are crucial in impacting departmental climate, conveying expectations, and providing merit assessments. Therefore, they have the most influence in retaining highly qualified faculty. Most department chairs come from the faculty ranks and lack formal training in key management, communication, and administrative skills, including performance reviews, resource allocation and budgeting, legal and compliance issues, promotion and tenure determinations, conflict resolution, and the inclusive management of people with diverse identities. Recognizing the critical role of department chairs and the evident gap in their training, we developed a series of chair workshops to provide ongoing professional development for department chairs across …

Emergent Magnetism And Hyperthermia In Phase- And Size-Tunable Iron Oxide Nanostructures, K Mudiyanselage Tharindu Supun Bandara Attanayake

USF Tampa Graduate Theses and Dissertations

Iron oxide nanoparticles (IONPs) hold immense potential across diverse fields, from spintronics, magnetic hyperthermia to drug delivery, biodetection, and magnetic resonance imaging. Unlocking these applications hinges on our ability to tailor the magnetic properties of IONPs, and this dissertation presents novel and powerful approaches for enhancing magnetic and hyperthermic responses of multiphase iron oxide nanostructures. This is achieved by manipulating their phase volume fraction, size, and shape with a focus on the magnetic tunability of nanostructures via strategic control over structural and environmental parameters. The aforementioned has been achieved by the following three key approaches: (i) phase-tunability of iron oxide …

Chemical Herding As A Multiplicative Factor For Top-Down Manipulation Of Colloids, Mark N. Mcdonald, Douglas R. Tree, Cameron K. Peterson

Faculty Publications

Colloidal particles can create reconfigurable nanomaterials, with applications such as color-changing, self-repairing, and self-regulating materials and reconfigurable drug delivery systems. However, top-down methods for manipulating colloids are limited in the scale they can control. We consider here a new method for using chemical reactions to multiply the effects of existing top-down colloidal manipulation methods to arrange large numbers of colloids with single-particle precision, which we refer to as chemical herding. Using simulation-based methods, we show that if a set of chemically active colloids (herders) can be steered using external forces (i.e., electrophoretic, dielectrophoretic, magnetic, or optical forces), then a larger …

Electrochemical Identification Of Metal Chlorides In Eutectic Licl-Kcl Without Prior Knowledge Of Analyte Identities, Tyler Williams, Jason Torrie, Mark Schvaneveldt, Ranon Fuller, Greg Chipman, Devin Rappleye

Faculty Publications

The identities of unknown analytes within four eutectic LiCl-KCl melts were determined using electrochemical methods, simulating the uncertainty of electrochemically probing an electrorefiner salt bath or molten salt nuclear reactor. With a variety of electrochemical methods (e.g. cyclic voltammetry, chronopotentiometry, and square-wave voltammetry), and electroanalytical techniques (e.g. semi-differentiation), every analyte was positively identified, although one false positive occurred because of an unexpected chemical interaction. This study highlights some remaining challenges for the use of electrochemical sensors in nuclear material control and accountability in molten salts: (1) quantification of analytes without the use of calibration curves (e.g. error in property values, …

Method For Separating Individual Cathode-Active Materials From Li-Ion Batteries, Lei Pan, Tinuade Ololade Folayan, Jeffrey S. Spangenberger, Bryant J. Polzin

Michigan Tech Patents

Method of separating individual cathode active materials from a mixture of cathode active materials by froth flotation has been developed. They are based on using appropriate chemical reagents that selectively hydrophobize individual cathode active materials to be recovered, so that they can be collected by air bubbles used in flotation and separated from other mixtures. The chemical reagents are amphiphilic molecules with specialized head groups have a strong affinity to metal elements on surfaces of cathode materials. This method enables a separation of individual cathode active material from a mixture of cathode active materials.

Operation Of A Packed Bed Reactor For Hyrdogenation, Austin Joseph Urfer

Graduate Theses - Chemical Engineering

The primary goals of this research were to develop an efficient standard operating procedure for undergraduate students and researchers performing reactions within a packed bed reactor and to determine the optimal operating conditions for phenethylamine formation from mandelonitrile hydrogenation. With the current laboratory packed bed reactor system, undergraduates can conduct gas-liquid phase reactions at a maximum temperature of 95℃ and a maximum pressure of 100 psi. The versatile system setup can be modified for unit operations laboratory instruction or future researchers analyzing heterogeneous catalysis reactions. The developed standard operating procedure provides detailed instructions on packing the reactor with a solid …

Creating Advanced Processes Through Utilizing Renewable Eutectics For Gas Capture And Separation, Ahmad Mohammad Rasheed Al-Bodour

Dissertations

Global efforts to reduce emissions of environmentally harmful gases have intensified, with carbon dioxide (CO2) being identified as the most significant greenhouse gas and a key target for reduction strategies. Carbon dioxide (CO2) has the highest potential of threatening the environment. It is recognized as one of the greenhouse gases which has the potential of negative effects on the human being, atmosphere, and the environment. Even though CO2 gas has negative effects but at the same time it has high potential to be exploited in beneficial ways. For instance, CO2 is used in the energy field to produce the so-called …

The Synthesis, Characterization, And Application Of Polysaccharide-Based Additive To Improve Wet And Dry Strength And High-Barrier Properties Of Paper Products, Cornellius Marcello

Dissertations

Paper products play an essential role in our daily lives owing to their low cost, environment-friendly character, renewability, and recyclability. Paper manufacturers have been using petroleum-based strength additives (cPAM, GPAM, PAE) to meet the perceived needs of customers. On the other hand, paper produced from cellulose is hydrophilic and porous, leading to shallow water and grease resistance, causing paper manufacturers to use many kinds of coating materials such as poly-fluoroalkyl substances (PFAS) and synthetic plastic to improve water resistance, especially for food packaging paper products like cups, plates, food boxes, and packaging. However, PFAS are identified as likely carcinogenic to …

Using Micromoments And Concept Maps To Enhance Entrepreneurially Minded Learning Of Indoor Air Pollution Control, Jean M. Andino, Erick Salvador Vasquez-Guardado, Ricardo Gomez Gonzalez, Xiaojing Yuan, Nilza D. Aples

Chemical and Materials Engineering Faculty Publications

Micromoments targeted toward indoor air quality were introduced to students in an Air Quality Engineering course to enhance their entrepreneurial mindset. Three micromoment activities, i.e., “Question Frenzy”, “Make It Relevant”, and “How Do We Make It Better?” that are linked, respectively, to the curiosity, connections, and creating value elements of EM were deployed in the class in the context of the use of a Corsi Rosenthal cube (a do-it-yourself structure that has recently become popular as an inexpensive way to reduce indoor particle pollution). Students generated concept maps pre-and post- micromoment intervention using the freely available CMap Tools software. The …

Creation And Fill Of An Eocene Incision On A Leeward Margin Of An Isolated Carbonate Platform, Northeast Sirte Basin, Libya, Muneer Abdalla, Wan Yang, Abdlsaid Ibrahem, Salah Hassan, Alzobeere Bogzil

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The recognition of incised valleys and the reconstruction of their filling history are significant for defining unconformity surfaces and their stratigraphic framework, particularly when detailed petrographic data are missing. However, little of such research is published so far on the characterization and factors influencing the development of incised valleys using three-dimensional seismic and well data. Thus, this work aims to examine and analyze the geometry and factors controlling the formation and sediments filling of an eocene incised valley in a sequence stratigraphic frame using an integration of three-dimensional seismic and well data from ne sirte basin, libya. The eocene incised …

Lithospheric Evolution Of The South-Central United States Constrained By Joint Inversion Of Receiver Functions And Surface Wave Dispersion, Tuo Wang, Stephen S. Gao, Kelly H. Liu, Kevin L. Mickus, Ling Chen

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

In the present study, we use broadband seismic data recorded by 190 stations of the EarthScope program's Transportable Array to construct a 3-D shear wave velocity model for the upper 180 km using a non-linear Bayesian Monte-Carlo joint inversion of receiver functions (RFs) and Rayleigh wave dispersion curves. Ambient noise and teleseismic data are used for obtaining Rayleigh wave phase velocity dispersion curves. A resonance removal filtering technique is applied to the RFs contaminated by reverberations from the thick sedimentary layers that cover most of the region. Our observations of the higher crustal shear velocities (∼3.40 km/s) beneath the Sabine …

Experimental Investigation Of Liquid Holdup In A Co-Current Gas–Liquid Upflow Moving Packed Bed Reactor With Porous Catalyst Using Gamma-Ray Densitometry, Ali Toukan, Ahmed Jasim, Vineet Alexander, Hamza Albazzaz, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

This study explores the dynamics of liquid holdup in a lab-scale co-current two-phase up flow moving packed bed reactor, specifically examining how superficial gas velocity influences the line average external liquid holdup at a fixed superficial liquid velocity. Utilizing gamma-ray densitometry (GRD) for precise measurements, this research extends to determining line average internal porosity within catalyst particles. Conducted with an air–water system within a bed packed with 3 mm porous particles, the study presents a novel methodology using Beer–Lambert's law to calculate liquid, gas, and solid holdups and catalyst porosity that is equivalent to the internal liquid holdup that fills …

Assessing Global Engagement Interventions To Advance Global Engineering Competence For Engineering Formation, Scott Schneider, Erick S. Vasquez-Guardado, Corinne Mowrey, Michael Moulton, Homero Murzi, Matthew A. Witenstein

Chemical and Materials Engineering Faculty Publications

This paper summarizes the work performed during the first year of a collaborative Research Initiation in Engineering Formation (RIEF) project focused on assessing the formation of a global learner mindset in engineering students through the use of different types of global engagement interventions without extended international travel. During this year the global engagement interventions have been developed, piloted, and assessed using the Global Engagement Survey (GES) and Global Engineering Competency Scale (GECS) instruments in a pre and post format. The assessment results helped the research team update the interventions and refine the assessment strategy, including the addition of new qualitative …

Work In Progress: Exploring The Impact Of International Experiences On The Development Of Students’ Entrepreneurial Mindset, Olgha Bassam Qaqish, Marcia Poole, William Pennock, Erick S. Vasquez-Guardado, Fahmidah Ummul Ashraf

Chemical and Materials Engineering Faculty Publications

International experiences, including collaborative online international learning (COIL) experiences that naturally increase accessibility, are of interest to many undergraduate students. These experiences provide educators a unique opportunity to develop a student's entrepreneurial mindset (EM). Additionally, hands-on experiences aligned with the National Academy of Engineering’s (NAE) grand challenge themes (Sustainability, Security, Health, and Joy of Living) support connections between the experience, disciplinary knowledge, multicultural awareness, and EM. Through this Work-in-Progress (WiP) study, we seek to answer: 1) How do international experiences influence undergraduate science and engineering students’ EM, and 2) How does the international experience modality (i.e., study abroad or COIL) …

Enhancing Entrepreneurial Minded Learning Of Process Control And Heat Transfer Concepts Using Micromoments And Concept Maps, Erick S. Vasquez-Guardado, Ricardo Gomez Gonzalez, Jean M. Andino, Nilza D. Aples, Xiaojing Yuan

Chemical and Materials Engineering Faculty Publications

The Entrepreneurially Minded Learning (EML) Framework seeks to infuse an Entrepreneurial Mindset in engineering students. The EML framework is founded on the 3 C’s principles of curiosity, connections, and creating value. Assessing EML efforts, however, is a well-known challenge for many engineering courses that do not have a design component. Through concept maps and micromoment activities, this work seeks to answer the following questions: Does implementing micromoment activities enhance students’ EML in two core areas of chemical engineering, i.e., heat transfer and process controls? A secondary research question is whether introducing a physical device in lectures enhances students’ EML. The …

A New Design Strategy For Sizes Of Polymer Gel Treatments Derived From A Comprehensive Assessment Of Their Case Histories, Munqith Aldhaheri, Abdullah Almansour, Na Zhang, Mingzhen Wei, Baojun Bai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The incentive to revive brownfield oil production extends the interest to apply polymer gel treatments in injection wells. Virtually, volumes of previous remediations implemented in similar reservoir types are used to size new jobs. Such an analogy-based design procedure imposes a need to evaluate the most frequent designs for each reservoir type based on a comprehensive field survey. This survey provides a new treatment sizing strategy for polyacrylamide-polymer bulk gels by reviewing their field applications in 653 injection wells. The new strategy proposes using the average and most frequent gel volumes per reservoir type as an initial estimate of the …

A New Design Strategy For Sizes Of Polymer Gel Treatments Derived From A Comprehensive Assessment Of Their Case Histories, Munqith Aldhaheri, Abdullah Almansour, Na Zhang, Mingzhen Wei, Baojun Bai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The incentive to revive brownfield oil production extends the interest to apply polymer gel treatments in injection wells. Virtually, volumes of previous remediations implemented in similar reservoir types are used to size new jobs. Such an analogy-Based design procedure imposes a need to evaluate the most frequent designs for each reservoir type based on a comprehensive field survey. This survey provides a new treatment sizing strategy for polyacrylamide-polymer bulk gels by reviewing their field applications in 653 injection wells. the new strategy proposes using the average and most frequent gel volumes per reservoir type as an initial estimate of the …

Understanding The Impact Of Microplastic Contamination On Soil Quality And Eco-Toxicological Risks In Horticulture: A Comprehensive Review, N. P. Gayathri, Geena Prasad, Vaishna Prabhakaran, Vishnu Priya

Research outputs 2022 to 2026

The horticulture sector, essential for global food production, confronts significant challenges with prevalent pollutants, mainly microplastics. The presence of microplastics in the food chain has induced physiological stress and a multifactorial food safety concern. The complexity of the problem, arising from intricate interactions among microplastics, organisms, and ecosystems, poses a substantial challenge to food safety, necessitating an immediate strategic perspective due to the associated risks to human health and eco-toxicology. Significant knowledge gaps persist regarding their impact on terrestrial ecosystems, especially in horticulture. This study addresses the urgent need to comprehend the implications of microplastics on soil health, eco-toxicological risks, …

An Analytical Investigation Into Solute Transport And Sorption Via Intra-Particle Diffusion In The Dual-Porosity Limit, Lucy C. Auton, Maria Aguareles, Abel Valverde, Timothy G. Myers, Marc Calvo-Schwarzwalder

All Works

We develop a mathematical model for adsorption based on averaging the flow around, and diffusion inside, adsorbent particles in a column. The model involves three coupled partial differential equations for the contaminant concentration both in the carrier fluid and within the particle as well as the adsorption rate. The adsorption rate is modelled using the Sips equation, which is suitable for describing both physical and chemical adsorption mechanisms. Non-dimensionalisation is used to determine the controlling parameter groups as well as to determine negligible terms and so reduce the system complexity. The inclusion of intra-particle diffusion introduces new dimensionless parameters to …

Simulation Of Heat And Mass Transfer In A Refractance Window Dryer For Aloe Vera Gel, A. Shahraki, M. Khojastehpour, M. R. Golzarian, E. Azarpazhooh

Research outputs 2022 to 2026

Introduction Drying is one of the oldest methods of food preservation. To increase the efficiency of heat and mass transfer while maintaining product quality, the study of the drying process is crucial scientifically and meticulously. It is possible to conduct experimental tests, trial and error, in the drying process. However, this approach consumes time and cost, with a significant amount of energy resources. By harnessing available software and leveraging technological advancement to develop a general model for drying food under varying initial conditions, the drying process can be significantly optimized. Materials and Methods This study was conducted with the aim …

Interaction Of Particles With Plasma And Shock Produced By Pulsed Spark Discharge, Shomik Mukhopadhyay

Dissertations

Interactions of powders with high-temperature plasma and shockwaves occur in diverse scenarios, such as nuclear blasts, accidental industrial dust explosions, solid propellant combustion in explosive charges and when removing contaminants from surfaces. Electrostatic Discharge (ESD), known for generating shock and plasma, is a promising lab-scale technique for simulating these interactions. Studies with ESD involved placing powders near a spark-producing gap between electrodes and observing mechanical and chemical processes like particle motion and ignition. A limited range of spark conditions and material properties have been tested, which facilitated the development and validation of preliminary computational models describing this system. Significant gaps …

Molecular-To-Continuum Scale Modeling Of Aerosols: Atmospheric Application And Beyond, Ella Ivanova

Dissertations

Aerosol modeling is critical for various applications, such as climate forecasting, air quality, and human health impact assessment. During their lifetime, aerosols undergo a complex evolution, usually divided into several stages — formation, processing, transport, and removal — that occur on different scales. Thus, the choice of modeling methods depends on the stage considered. For example, certain stages of particle formation may require nano-scale modeling while aerosol-cloud interactions span from microscale to mesoscale. This study examines the modeling of aerosol behavior over a wide range of scales, from nano to microscale, with implications to mesoscale.

This dissertation focuses on two …

Microplastic Abundance And Removal In Stormwater Using Green Infrastructure, Meghana Parameswarappa Jayalakshmamma

Dissertations

Microplastics (MPs) are increasingly recognized as a pervasive environmental contaminant, conveying other contaminants, accumulating in aquatic organisms, and posing ecological risks. The existing research has primarily focused on MPs in wastewater treatment plant effluents in surface waters. However, the role of stormwater systems in MP transport has been less explored. Given the rise in MPs from urban sources, stormwater runoff from urban areas may serve as a critical conduit for transporting land-based MPs into aquatic environments. Green infrastructures (GIs) have been recognized for mitigating flooding and improving water quality from minor storms by trapping stormwater pollutants. Yet, the capability of …

Electrochemical Nitrate Reduction To Ammonia On Cu Based Nanoparticles Using Quantum Mechanical Simulations, Kathan Bhavin Shukla

Theses

Nitrate reduction to ammonia (NRA) is critical for environmental remediation and energy conservation, as it can remove harmful nitrate (NO₃^-) from water sources while producing usable ammonia (NH₃). Cu represents one of the most promising non-noble-metal NRA electrocatalysts. However, the intrinsic catalytic activity of Cu facets and their influence under different pH conditions remain unclear, particularly in the presence of ions commonly found in wastewater such as Cl^-, Na⁺, Mg²⁺, and Ca²⁺. Using density functional theory (DFT) calculations, we evaluated the nitrate reduction to ammonia (NRA) pathways …