Chemical Engineering Commons^™

Electrospun Pan-Derived Carbon Nanofibers Embedded With Nicofew-Based High-Entropy Oxides For Electrocatalytic Oxygen Evolution Reaction, Alireza Noroozi, Mahdavi, M. Baris Yagci, Mohammad Mahdi A. Shirazi, Saeed Bazgir, Hadi Jahangiri, Uğur Ünal

Research outputs 2022 to 2026

High-entropy oxides composed of Ni, Co, Fe, W, and a fifth transition element (Mo, Mn, or Cu) were integrated into electrospun polyacrylonitrile nanofibers to form porous nitrogen-doped carbon membranes for the oxygen evolution reaction. Gas-assisted electrospinning enabled uniform dispersion of high-entropy oxide nanoparticles within the polyacrylonitrile matrix, while calcination at 800°C produced conductive carbon frameworks embedding crystalline high-entropy oxides with homogeneous elemental distribution. Structural and surface analyses confirmed the preservation of high-entropy oxide phases, catalytic graphitization of the carbon matrix, and strong interfacial bonding between metal oxides and carbon. Among all compositions, Mo-HEO@NC exhibited the lowest overpotential (≈240 mV at …

Effects Of Hofmeister Ions On Lower Critical Solution Temperatures Of Poly(N-Isopropylacrylamide) And Poly(Vinyl Methyl Ether), Joseph Joaquin

Williams Honors College, Honors Research Projects

The goal of this study is to compare how four different Hofmeister anions (Cl-, SCN-, F-, and I-) affect the Lower Critical Solution temperature (LCST) on two thermo-responsive polymers: poly(N-isopropylacrylamide) (pNIPAAM) and poly(vinyl methyl ether) (PVME). pNIPAAm is commonly used in the environmental applications such as monitoring, oil-water separations, or antifouling materials, and in medical industry from drug delivery to tissue engineering. When pNIPAAM or PVME reaches a temperature above their LCST, they become hydrophobic, and the polymer chains coiled, leading to their aqueous solutions turn opaque. PVME exhibits a similar LCST as that of pNIPAAM, so it can be …

Experimental Evaluation Of Novel Nano Polymer Hybrid Enhanced Oil Recovery In Carbonate Reservoir, Altamish Ahmed Pakeer

Theses

Innovative enhanced oil recovery (EOR) strategies are needed to unlock additional reserves in heterogeneous, oil-wet carbonate reservoirs. This study evaluates hybrid nano-polymer flooding by integrating silica nanoparticles (SiO₂) and single-walled carbon nanotubes (CNT) with novel HPAM polymers (Sav10 and Sav10 VHM) to optimize wettability alteration, rheological parameters, and recovery mechanisms.

A comprehensive experimental approach was employed, where rheological tests assessed viscosity enhancement under varying shear conditions, and wettability alteration was quantified via contact angle measurements using HPAM-SiO₂, HPAM-CNT, Sav10 VHM-SiO₂, and Sav10 VHM-CNT systems. Core floods were performed in three consecutive phases; waterflooding (baseline), standalone nanoparticle flooding, and hybrid nano-polymer …

Development And Characterization Of Polysaccharide-Based Controlled Drug Delivery Platforms, Amanda Pepler

Open Access Dissertations

Drug delivery research focuses on overcoming challenges in patient treatment. Most therapeutics are delivered systemically through oral or intravenous routes. However, these administration methods are often inefficient due to therapeutic hydrophobicity, poor bioavailability, and liver metabolic clearance, necessitating frequent dosing. When treatment plans require frequent dosing, patients experience significant fluctuations in therapeutic concentration in the bloodstream, which can increase adverse side effects. These factors contribute to low patient compliance. Therefore, the core focus of drug delivery research is to develop new administration routes for therapeutics. Drug delivery systems (DDS) that can target therapeutics to a localized region offer advantages over …

Investigation Of The Transport And Plugging Behavior Of Preformed Particle Gels (Ppgs) In Fractures For Conformance Control In Carbonate Reservoirs, Abdulaziz A. Almakimi

Doctoral Dissertations

This study aims to systematically evaluate the performance of preformed particle gels (PPGs) in fractured carbonates mainly through a series of core flooding experiments. Carbonate reservoirs exhibit unique features of heterogeneity and pore geometry, while (PPGs) are known for their plugging efficiency, deformability, and dehydratable nature. The main goal of gel injection in fractured reservoirs is to place a gel pack appropriately into the fracture, diverting injected fluid to the oil-bearing matrix and reducing excessive water production. However, considerable dehydration of (PPGs) is possible at the adjacent matrix and within the fracture, which could lead to a filter-cake formation and/or …

Sulfonated Ionomer Composite Membranes For Use In Vanadium Redox Flow Batteries, Xueting Wang

All Dissertations

While vanadium redox flow batteries (VRFBs) have garnered significant attention as a promising scalable energy storage technology, the current membrane material used in this technology, Nafion™, suffers from high cross mixing of vanadium ions in the liquid electrolytes, directly impacting battery performance properties such as the voltage and coulombic efficiencies, as well as resulting in a reduction in the overall battery lifetime. The use of ionomer nancomposites has proven to be one promising route of directly addressing the issue of high ion crossover, though the mechanism by which the nanoparticles act to reduce crossover remains in open question. Herein, the …

Exploring Natural Raw Materials For The Development Of Hot Melt Adhesives For Linings Of Paintings, Erica Factor

Williams Honors College, Honors Research Projects

Natural raw materials will be explored for developing hot melt adhesives for the lining of paintings. The leading raw material is a natural resin called "Damar". This resin is obtained from the tree family Dipterocaupocea in India and Southeast Asia. This material has shown promising results from initial testing. Damar, with the potential for other natural raw materials, will be combined with synthetic ingredients to create sustainable formulations. The formulations will be tested on linen to replicate the application onto paintings. The sustainability, tackiness, texture, and overall performance of each formula will be considered. Once a formulation has been selected, …

Using Afm-Ir To Study Nanoscopic Phase Behavior Of Polymer Blends And Photovoltaic Bulk Heterojunctions, Nathaniel L. Prine

Dissertations

Conjugated polymers (CPs) and polymer blends harbor the potential for high-performance organic solar cells (OSCs) due to their short energy payback time, low cost, solution processability, lightweight attributes, and flexibility. However, OSCs suffer from poor thermal stability compared to their inorganic equivalents. This study explores the thermal instability of OSCs, focusing on phase separation of the photoactive layer under heat, resulting in morphology changes and degradation of power conversion efficiency (PCE). Utilizing atomic-force microscopy coupled with infrared spectroscopy (AFM-IR) and differential scanning calorimetry (DSC), we delve into thermal stability-morphology relationships to devise strategies to improve OSC blend durability under thermal …

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 Ester As Membranes For Controlled Release Fertilizer’S, Muhammed Salman Fajis

USF Tampa Graduate Theses and Dissertations

Growing environmental pollution and non-sustainable materials has escalated the need for research in sustainable practices for many areas including crop production and fertilization. The conventional coating for the controlled-release fertilizers (CRFs) is non-biodegradable. Hence, the development of novel biodegradable coatings for fertilizer prills has emerged as an important area of study. In this thesis, conducting synthesis and application of cellulose esters (biomass membrane) as an encapsulation for the controlled release fertilizers. Therefore, the coating would be effective for a controlled release of nutrients to the crops by sustaining nature. Here, synthesized biodegradable cellulose esters by 8 and 16-carbon fatty acids …

A Review Of Polymer – Particles Composite Materials, Ismail Ibrahim Marhoon, Ayad Abbood Abdul Al-Hassan, Mohammed Ali Abdulrehman

Al-Esraa University College Journal for Engineering Sciences

In several engineering applications traditional materials are replacedby composite materials. Filled composite materials consist of the continuousmatrix and the filling particles. The primary purpose of introducing inorganicsolid particles into polymers is to essentially increase mechanical and physicalproperties. The wear properties of polymer composite can be changed to agreater degree by modifying the process of preparing the filled compositematerials. In the present review, a large-scale research has been conductedon the effect of wear on the composites of polymers. The effect of filler onthe polymer composites wear behavior has been thoroughly explained

The Cosolvent And Association Effect On Polymer Behaviors, Xiangyu Zhang

Theses and Dissertations

The blending or mixing is extensively utilized in diverse processes of polymers to bring about advantageous properties, but the behavior becomes intriguing when associations are involved and multi-solvents are used. Explanations based on chemistry-specific arguments are less than satisfactory in abstracting essential features, and lack the general applicability across various systems. So, this work focuses on capturing the physical force governing the phenomenon of interest by using a generic model. Highly non-trivial behaviors of polymers are often observed in multi-solvent solutions. It is known that polymers swell and dissolve in good solvents, while they tend to collapse and aggregate in …

Advancing Ionomer Design To Boost Interfacial And Thin-Film Proton Conductivity Via Styrene-Calix[4]Arene-Based Ionomers, Shyambo Chatterjee, Oghenetega Allen Obewhere, Ehsan Zamani, Rajesh Keloth, Seefat Farzin, Martha D. Morton, Anandakumar Sarella, Shudipto Konika Dishari

Department of Chemical and Biomolecular Engineering: Faculty Publications

Sub-micrometer-thick ion-conducting polymer (ionomer) layers often suffer from poor ionic conductivity at the substrate/catalyst interface. The weak proton conductivity makes the electrochemical reaction at the cathode of proton-exchange-membrane fuel cells sluggish. To address this, here we report on a class of polystyrene-based ionomers having sub-nanometer-sized, sulfonated macrocyclic calix[4]arene-based pendants (PS-calix). In films with thickness comparable to that of ionomer-based binder layers, the conductivity of PS-calix film (∼41 mS/cm) is ∼13 times higher than that of the current state-of-the-art ionomer, Nafion. We observe a similar improvement in proton conductivity when PS-calix interfaces with Pt nanoparticles, demonstrating the potential of PS-calix in …

Demonstration Of High Detoxification Efficiency Of Glassy Polymer-Metal Hydroxide Composites Toward Chemical Warfare Agent Simulants, Peter O. Aina, Sukanta K. Mondal, Joshua Costain, Ali A. Rownaghi, Fateme Rezaei

Chemical and Biochemical Engineering Faculty Research & Creative Works

The design and development of polymeric composites that can effectively capture and destruct toxic chemicals with a fast detoxification rate is of high importance for protecting the military, first responders, and civilians. Here we report the synthesis and assessment of zirconium hydroxide (Zr (OH)4)-incorporated Ultem, Matrimid, and PIM-1 composites for detoxification of dimethyl 4-nitrophenylphosphonate (DMNP), as a type G toxic nerve agent simulant. Maintaining homogeneity, three different loadings (8, 20, 30 wt %) of Zr (OH)4 were incorporated into the polymers, and the thin films of composite materials were developed for subsequent hydrolysis tests. Our results indicated that increasing the …

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 …

Correlating The Macrostructural Variations Of An Ion Gel With Its Carbon Dioxide Sorption Capacity, Tung Nguyen,, Mona Bavarian, Siamak Nejati

Department of Chemical and Biomolecular Engineering: Faculty Publications

We report on a direct correlation between the macroscale structural variations and the gas sorption capacities of an ion gel. Here, we chose 1-ethyl-3-methylimidazolium bis(trifluoromethyl sulfonyl)imide ([Emim][TF₂N]) and poly(vinylidene fluoride)-co-hexafluoropropylene (PVDF-HFP) as the ionic liquid and host polymer, respectively. The CO₂ sorption in the thin films of the IL-polymer was measured using the gravimetric method. The results of our experiment showed that the trend in CO₂ uptake of these mixtures was nonlinearly correlated with the content of IL. Here, we highlight that the variations in the molecular structure of the polymers were the main reason behind …

Sustainable Polylactic Acid Foam Development Through Solid-State Processing, Philip Onffroy

Honors Theses

Plastics play a vital role in global materials industries, but they contribute to environmental and ecological toxicity effects that accelerate climate change. One important category of plastic material is polymer foams, which have widespread applications in insulation, packaging, and storage. Current bio-based plastic foams that originate from natural, non-petroleum feedstocks are potential solutions but do not yet have adequate properties to supplant petrochemical-based plastic foams. This project aims to generate, test, and analyze bio-based polylactic acid (PLA) polymer foams developed through methods involving solid-state processing such as solid-state shear pulverization (SSSP) and cryogenic milling. SSSP has previously been shown to …

Wetting Transition On 3d-Printed Surfaces, Isabelle Moryan

Williams Honors College, Honors Research Projects

Taking the previous research conducted, this project aims to further the study and research of the wettability of surfaces. Surface features and types are important factors to their wettability. The geometric properties of a surface can make it more hydrophobic and hydrophilic. Extreme cases of hydrophobic and hydrophilic surfaces lead to water repulsion or water absorption, even under extreme conditions. The goal of this project is to gain further insight on how fabricated 3D-printed featured surfaces and examine the wetting transition on these surfaces. In particular, cylindrical pillars will be studied with varied pillar spacing, height and diameter. In addition, …

Amine-Functionalized Interpenetrating Polymer Networks For Co2 Capture, James Wills

Williams Honors College, Honors Research Projects

The research performed looked to advance the studies of vacuum swing absorption of Carbon Dioxide to help combat global climate change issues. The focus of the project was to create an anime-polymer sorbent that will weakly absorb and desorb CO2. The sorbent must be durable and be able to withstand multiple uses. The creation of a porous polymer matrix aided in the amines' ability to absorb CO2. Created samples underwent several qualitative and quantitative tests to determine their usefulness as an industrial sorbent. Infrared spectroscopy was used to study the effectiveness of the amine sorbents. Studying the changes in the …

Mimicking The Namib Desert Beetle With Hydrophilic And Hydrophobic Surfaces, Tyler Bracewell

Williams Honors College, Honors Research Projects

The Namib Desert beetle, Stenocara gracilipes, condenses fog that rolls in off the west coast of Namibia to provide itself with the water it needs for the day. By lifting its abdomen into the air to collect the water vapor, it condenses on hydrophilic bumps that are about 500μm in diameter and are spaced apart about 500-1500μm. Once the water reaches a critical size, the droplet rolls off the hydrophilic bump and onto the flat hydrophobic surface of the elytra. Since the beetle is angled with its abdomen in the air, the water rolls down to its mouth. A …

Sealant Injectivity Through Void Space Conduits To Assess Remediation Of Well Cement Failure, Mohammed Alkhamis, Abdulmohsin Imqam

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The primary cement of oil and gas wells is prone to fail under downhole conditions. Thus, a remedial operation must be conducted to restore the wellbore integrity and provides zonal isolation. Many types of materials are currently used and/or have the potential to be employed in wellbore integrity applications, including, but not limited to, conventional Portland cement, microfine and ultrafine cement, thermoset materials, and thermoplastic materials. In this study, several types of materials were selected for evaluation: (1) conventional Portland cement, which is the most widely used in remedial operations in the petroleum industry, (2) polymer resin, which is one …

Enhancement Of Electrospun Nanofiber Properties Via Automated Track Post-Draw Processing, David Anthony Brennan

Theses and Dissertations

Electrospinning is an alternative manufacturing method, capable of producing fibers with nanoscale diameters from a wide range of different polymers in a process which is relatively simple and inexpensive in comparison to other forms of nanofiber production. This has made electrospinning the subject a great deal of research as a method of producing nanofibers for various high-performance applications. However, electrospun nanofiber tensile strength is weak in comparison to conventional fibers of the same material, preventing widespread use and marketization. This disparity in mechanical strength is attributed to poor polymer chain alignment in individual fibers, caused by the absence of a …

An Investigation Of Cross-Links On Crystallization And Degradation In A Novel, Photocross-Linkable Poly (Lactic Acid) System, Nicholas Baksh

USF Tampa Graduate Theses and Dissertations

Polymeric molecular structure consists of repeating units bonded together. Mechanicalproperties can be altered without affecting chemical makeup by altering the number of these units. Small molecules can be introduced and/or polymers can be modified to form bonds between molecular chains. Cross-linking, as this is called, also introduces mechanical variation with minimal effects on chemical composition. Lastly, polymer chains reorient themselves in response to intermolecular forces. This temperature dependent response is known as crystallization. Although chemistry is unaltered, mechanical properties can depend highly on the percent of the sample that is crystallized.

Cross-linking is known to enhance the mechanical properties of …

Catalysts For Polymer Membrane Fuel Cells, William E. Mustain, Bryan Pivovar

Faculty Publications

No abstract provided.

Self-Assembled Metal Nanoparticle/Polymer Nanocomposites As Nanoreactors For One-Pot Reactions, Andrew Harrison

Theses and Dissertations

Polymer nanoreactors incorporating gold nanoparticle catalysts were self-assembled via Flash Nanoprecipitation. The incorporated gold nanoparticles maintained catalytic activity, which was evaluated using reduction of 4-nitrophenol with sodium borohydride as a model reaction. The diffusion coefficient for 4-nitrophenol was determined by NMR and used to calculate the second Damköhler number, which indicated that the systems were not diffusion limited. Despite similar diffusion coefficients, catalytic performance was strongly affected by the co-precipitant. For example, the apparent reaction rate per surface area using castor oil was over 8-fold greater than polystyrene. Thus, we measured the partition coefficient of 4-nitrophenol between water and castor …

A Comparison Of Fiber Mat Thickness Measurement Techniques Using Laser Interferometry And Water Displacement, Ryan Seabeck

Williams Honors College, Honors Research Projects

Polymer fiber mats may often be very thin which leads to complications in measuring thickness. The thickness of fiber mats, however, is crucial in understanding their behavior. Thickness affects how well the mat works as a filter as well as the pressure drop across the mat, and herein lies the need for accurate measurement techniques. Currently two of the available techniques for measuring mat thickness are by laser interferometry[1] and by buoyancy force when submerged in water[2]. Instead of measuring the buoyancy force in this experiment, an enclosure intended to measure the thickness via water displacement was …

Filtration Apparatus Design For Oil-Water Separation Using Membranes And Sponges, Alec Jerger

Williams Honors College, Honors Research Projects

It can be difficult to separate water and oil emulsions through traditional filtration. Therefore, investigations of filtering using thermo-responsive (TR) polymers, in this case poly(vinyl methyl ether) (PVME), was conducted. It’s hypothesized that below its lower critical solution temperature (LCST), PVME has an affinity for water while oil substances do not. Above the LCST the opposite will be true. To verify this hypothesis, iterations of filtration designs were created to provide optimum control over the parameters to measure flow. The final optimized experimental apparatus was a Chromaflex glass column which was air tight and controlled all parameters besides fluid flow. …

Effects Of Crosslinking Conditions On Biofouling Of Polymer Substrates With A Hydrogel Layer, Laura Davila

Williams Honors College, Honors Research Projects

The introduction of a hydrogel coating to a surface has been looked at for different benefits. Certain hydrogels offer antifouling properties that are beneficial to different applications like medical components. Previous attempts (2) (3)have been done to introduce a hydrogel surface to plastic substrates. One of them is to use grafting brushes which works properly but it is not sufficient since the layer is too thin and therefore can be damaged. The second method have a bulkier coating without crosslinking. Opposite to grafting brushes this method has too thick of a layer. Additionally, there is no crosslink therefore the coating …

Methods For Film Coating Electrospun Fibers, Kristopher Dejean

Williams Honors College, Honors Research Projects

Electrospinning uses high voltages to form polymer nanofiber membranes. These membranes have potential for use in filtration, tissue engineering, drug delivery, and catalysis. The nonwoven fiber mat is malleable but has a low tensile strength compared to a solid film of the same polymer. Joining the fibers with a thin film is desired to balance the strength and flexibility. Three methods of producing a film on fiber membrane were tested. The techniques are spraying then melting, spin coating, and dip coating. Electrospinning setup conditions, solvent ratios, damage to fibers, and spin coating speeds were determined. Research was abruptly stopped and …

Production Optimization Of Ring-Banded Spherulitic Crystals Of Poly (3-Butylthiophene-2,5-Diyl) Using Controlled Solution Evaporation, Frederick Paul Henderson Iii

Materials Engineering

Conductive polymers can carry a charge due to the presence of excess electrons along the carbon backbone. By growing these polymers into crystals, the usual insulative isotropic matrix that polymers form will be replaced with anisotropic regions where conduction is possible parallel to the crystal lattice growth direction. In previous research, while growing sphere shaped crystals it was observed that a few would exhibit rings that formed parallel to the circumference of the sphere. In this project, the conditions to produce this ring structure were examined by looking at two polymer solutions (with carbon disulfide or dichlorobenzene as solvent) and …