Chemistry Commons^™

Electrochemical And Morphological Properties Of Chloride-Doped Lithium Argyrodite Solid Electrolytes., William Richard Arnold

Electronic Theses and Dissertations

Recently, much attention has been devoted to the development of solid electrolytes to be used in all-solid-state-batteries. One group of promising solid electrolyte (SE) materials are lithium argyrodites, a class of superconductors which are noted for their high ionic conductivities. In particular, halogen doping has been shown to increase both conductivity and stability. The majority of research has focused on material synthesis through solid state reactions, but a novel liquid synthesis method for the preparation of Cl-doped Li7PS6 solid electrolyte provides the advantages of a homogenous product and a rapid, economic synthesis. Here this thesis focuses on the liquid synthesis …

The Regional Distribution And Molecular Interactions Of Phospholipids And Glucose In Mammalian Vitreous Humors., Abigail Nicole Schnepf

Electronic Theses and Dissertations

The vitreous humor (VH) is located in between the lens and the retina. It is composed of 98% water, hyaluronan (HA), collagen, proteins, phospholipids (PLs), and other metabolites. With aging, the VH undergoes liquefaction, a process that causes the gel-like structure of the VH to turn into a liquid and can lead to serious ocular diseases, including retinal detachment, vitreal detachment, and macular hole formation. The liquefaction process is expedited in diabetic VHs. This project focuses on understanding the molecular changes that lead to liquefaction and the reasons for which this process is accelerated with diabetes. Matrix-assisted laser desorption ionization/mass …

Diamond Intracrystalline Stable Isotope Chemical Image Analysis By Time-Of-Flight Secondary Ionization Mass Spectrometery, Tyler J. Sundell

Graduate Theses/Dissertations

The chemical resistance of diamond allows in-situ study of the diamond source regions. For a majority of gem quality diamonds, this source region is the sublithospheric mantle keel of a cratonic nuclei. Through analysis of stable isotopes, radiogenic isotopes and trace elements, diamond geochemical analyses can define chemical fluxes in the mantle keel. However, such studies require multiple methodologies for each chemical suite, high spatial resolution and analytical precision. Here, I evaluate Time-of-Flight Secondary Ionization Mass Spectrometer (ToF-SIMS) as an alternative method for diamond geochemical analyses. ToF-SIMS analysis can perform in cation and anion mode to measure the entire periodic …

Influence Of High Aspect Ratio Nanoparticle Filler Addition On Piezoelectric Nanocomposites, Jeremy A. Armas

Master's Theses

Piezoelectric nanogenerators (PNGs) are a new class of energy harvesting materials that show potential as a direct energy source for low powered electronics. Recently, piezoelectric polymers have been utilized for PNG technology due to low toxicity, high flexibility, and facile solution processing which provide manufacturing opportunities such as screen printing. Throughout the last decade, countless projects have focused on how to enhance the energy harvesting capabilities of these PNGs through the incorporation of nanoparticle fillers, which have been reported to enhance the piezoelectric properties of the film either directly through their intrinsic piezoelectric properties or through acting as surfaces for …

Cigarette Litter Leachates: A Statistical Study Of Elements In Freshwater And Saltwater, Cintly Guzman Hernandez

Honors Theses

Cigarette butts are the most common item found in coastal litter cleanups as approximately 4.5 trillion smoked cigarette butts are discarded into the environment every year. Cigarette butts can leach toxic heavy metals and nicotine along with other compounds from tobacco combustion. Past research in our lab has analyzed elements leached from cigarette butts into freshwater. The cigarette butts consisted of smoked and unsmoked butts that were soaked varying periods of time, and at different pH levels to identify the relationship of these variables to the amount of metal leached. The elements analyzed were Al, Ba, Cd, Cr, Cu, Fe, …

Mechanistic Study Of The Inhibition Of Rho Gtpase-Mediated Metastasis, Hope Gloria Umutesi

Chemistry & Biochemistry Dissertations - Archive

The Ras superfamily of small GTPases are monomeric proteins that bind guanine nucleotides, and regulate many cellular signaling pathways. They function as molecular switches by shuttling between active GTP-bound and inactive GDP-bound states. The Ras superfamily consists of its subfamilies including Ras and Rho GTPases. Ras and Rho GTPases function to regulate cellular growth, transformation, transport, motility, traffic, and adhesion. Small GTPases reactions often require regulators, such as guanine nucleotide exchange factors (GEFs) and GTPase Activating Proteins (GAPs). GEFs mediate fast release of GDP and allow loading with GTP while GAPs accelerate the GTP hydrolysis to GDP. Redox agents also …

Designing Thermally Stable Ionic Liquid Stationary Phases For Gas Chromatography And Examining Their Structure-Property Relationships, Rahul A. Patil

Chemistry & Biochemistry Dissertations - Archive

Ionic liquids are popular in diverse scientific applications because of their unique physicochemical properties. The physicochemical properties of ionic liquids can be “tuned” by the modification of their structural moieties. Understanding of structure-property relationship is important if one wants to introduce a desired property in ionic liquid for a specific application. The initial part of this thesis will discuss the understanding of structure-property relationship of dicationic ionic liquids. Ionic liquids with high thermal stability are useful in many applications from simple solvents for high temperature reactions to high vacuum lubricants for space applications. This thesis presents the design, synthesis, and …

Development Of Highly Polar Structurally-Tuned Ionic Liquids With Unique Selectivity For Gas Chromatography, Mohsen Talebi

Chemistry & Biochemistry Dissertations - Archive

Ionic Liquids (ILs) are state-of-the-art fluids that have found broad application in separation science. Owing to their unique physicochemical properties such as low vapor pressure, high thermal stability, and high viscosity, they were successfully used as stationary phase in gas chromatography (GC). By properly engineering their molecular structure, ionic liquids with tailor-made properties can be designed. Therefore, a systematic structure-function relationship can be established to study the effect of structural modification on the properties of ionic liquids. Herein, I describe the design and synthesis of several dicationic ionic liquids. The synthesized ILs were characterized in terms their physicochemical properties. The …

Unveiling Charge-Separation Dynamics In Cds/Metal–Organic Framework Composites For Enhanced Photocatalysis, Hai-Qun Xu, Sizhuo Yang, Xing Ma, Jier Huang, Hai-Long Wang

Chemistry Faculty Research and Publications

Photocatalytic water splitting for H₂ production becomes one of the most favorable pathways for solar energy utilization, while the charge-separation dynamics in composite photocatalysts is largely elusive. In the present work, CdS-decorated metal–organic framework (MOF) composites, namely, CdS/UiO-66, have been synthesized and exhibit high H₂ production activity from photocatalytic water splitting, far surpassing the MOF and CdS counterparts, under visible light irradiation. Transient absorption (TA) spectroscopy has been adopted in this report to unveil the charge-separation dynamics in CdS/UiO-66 composites, a key process that dictates their function in photocatalysis. We show that, in addition to the preferable formation …

Capillary-Tube Package Devices For The Quantitative Performance Evaluation Of Nuclear Magnetic Resonance Spectrometers And Pulse Sequences, Lingyu Chi, Ming Huang, Annalise R. Pfaff, Jie Huang, Rex E. Gerald Ii, Klaus Woelk

Electrical and Computer Engineering Faculty Research & Creative Works

With the increased sensitivity of modern nuclear magnetic resonance (NMR) spectrometers, the minimum amount needed for chemical-shift referencing of NMR spectra has decreased to a point where a few microliters can be sufficient to observe a reference signal. The reduction in the amount of required reference material is the basis for the NMR Capillary-tube Package (CapPack) platform that utilizes capillary tubes with inner diameters smaller than 150 µm as NMR-tube inserts for external reference standards. It is shown how commercially available electrophoresis capillary tubes with outer diameters of 360 µm are filled with reference liquids or solutions and then permanently …

Synthesis Of Dicamba Glucosides For The Study Of Environmental Dicamba Drift Effects On Soybeans, Holly Wallace

Graduate Theses and Dissertations

The most popular herbicide used for weed control has been glyphosate for many years in the Midwestern United States. Plants have begun to develop a resistance to glyphosate due to over use of the herbicide. This herbicide resistance has pushed farmers to turn to alternative herbicides such as dicamba and 2,4-D. Recently agrochemical companies have developed genetically modified crops that are resistant to herbicides such as dicamba. These modified crops allow farmers to spray their fields with dicamba without fear of crop damage. Farmers of non-genetically modified crops, however, suffer damage and loss of yield from herbicide drift effects of …

Synthesis, Characterization, And Catalytic Activity Of Copper Palladium Oxide Solid Solutions., Gregory L. Christensen

Department of Chemistry: Dissertations, Theses, and Student Research

Cu_xPd_1-xO forms a homogeneous solid solution over the wide range of 0 ≤ x ≤ 0.725 in which compositional variation can be correlated with structural and chemical environmental changes. After a small lag at low Cu²⁺ concentrations, where the lattice cell parameters are pinned to that of the pure PdO structure, Cu_xPd_1-xO lattice parameters follow Vegard’s law in which the cell volume decreases linearly with x, indicating a homogenous solution in which Cu²⁺ randomly replaces the larger Pd²⁺ cation. The crystal structure also undergoes an increase in the c/a …

Sem/Edx Analysis Of Bronze Disease, Brian Pauley, Nicole Bishop

Fall 2018 - Chemical Analysis Class Projects

Bronze disease is a type of self-progressing corrosion of bronze. This degradation is thought to be caused by humidity but proliferated through the formation of chlorine containing compounds that further react with the air. The origination of the bronze disease in this artifact is thought to have arisen from the tanning process used in the surrounding leather. It is highly probable that potassium chloride was used in the tanning process, providing the initial chlorides that cause bronze disease. The damage that this corrosion can cause can destroy priceless artifacts. An understanding of the bronze disease structure and chemical composition is …

Ft-Mir-Atr Of Organic Residues From Inside Peruvian Sacrificial Jars, Warren Rouse, Dr. Joshua Sebree

Fall 2018 - Chemical Analysis Class Projects

This project used various solvents in an attempt to determine the identity of the contents of Peruvian jars to determine their purpose.

A Compositional Study Of The Uni Museum Benin Bronzes Using Scanning Electron Microscopy, Elizabeth Akers

Fall 2018 - Chemical Analysis Class Projects

In 1897, the British empire annexed the kingdom of Benin in present day Nigeria.1 Many cultural artifacts, including a large collection of bronze statues and plaques, were taken and distributed among major museums

• Due to their increased demand, many sellers began creating fake bronzes to sell to tourists and collectors alike

• Four Benin bronze artifacts were donated to the museum in 1968 and have been questioned in terms of authenticity based on qualitative analyses

The Characterization Of Leather Wwii Artifacts Using Gc/Ms And Raman Spectroscopy, Brice Houser

Fall 2018 - Chemical Analysis Class Projects

Many museums face the challenge of protecting artifacts from deterioration. This process is often hampered by the history of the artifact, which can introduce factors that start or speed up the process of deterioration. An example of this is the method used during WW II to preserve leather. Mink oil or other fatty substances are used to help preserve and soften leather. A major component of mink oil is palmitic acid.

1 This fatty acid may have reacted with the brass in the same way that the oils from the hand react with coins to make that distinctive metallic smell, …

Determination Of Lead Content In Sidecar Coffee, Birk Shaikoski, Joshua Sebree

Fall 2018 - Chemical Analysis Class Projects

This project analyzed the amount of lead present in coffee beans from various parts of the world and decaffeinated beans.

Raman Spectroscopy Of Bronze Disease On Wwii Artifacts, Andrea M. Reutzel

Fall 2018 - Chemical Analysis Class Projects

Patina is a film that forms on bronze or similar metals over a long period of time due to an oxidation reaction. If cuprous chloride in copper alloys are present, it reacts with water to create hydrochloric acid. Hydrochloric acid in the presence of metals will cause corrosions of the bronze and over time it will completely eat away at the metal. This reaction, known as Bronze Disease, is different than patina. Patina can act as a coat and preserver for metals. The University of Northern Iowa’s Museum is experiencing Bronze Disease on artifacts in the WWII collection. The Bronze …

Quantification Of Trigonellinefrom Coffee Beans And Its Correlation With The Ph, Kashif A. Shaikh, Jaspreet K. Rishi, Joshua Sebree

Fall 2018 - Chemical Analysis Class Projects

This project analyzed the amount of trigonelline preseent in coffee beans at various stages of the roasting process.

Raman Spectroscopy For Authentication Of African Tribal Masks, Huzaifa Islam Shah, Joshua Sebree

Fall 2018 - Chemical Analysis Class Projects

University of Northern Iowa museum’s collection includes some wooden African tribal masks and African wood samples . Authenticity of the masks was doubted, therefore 5 of the masks and 27 different African wood samples were analyzed using Raman spectroscopy to determine the authenticity of the masks. The data obtained suggested that none of the masks were made up of the wood samples from Africa examined in the project.

Determination Of Caffeine In Peruvian Coffee At Different Levels Of Roast As Measured Through Capillary Electrophoresis, Jaspreet Kaur Rishi, Kashif Shaikh, Joshua Sebree

Fall 2018 - Chemical Analysis Class Projects

For this project, the amount of caffeine per gram of Peruvian coffee at different levels of roast was determined in 14 samples using capillary electrophoresis.

Compounds Of Coffee Over The Roasting Process, Alex Jaspering

Fall 2018 - Chemical Analysis Class Projects

The poster explores the changes in the concectration of chemical compounds as coffee beans are roasted.

Near-Infrared Spectroscopy Of African Tribal Masks, Jordan Smith, Huzaifa Shah, Kaitlyn Parrott

Fall 2018 - Chemical Analysis Class Projects

The project attempts to determine the authenticity of African masks using near-infrared spectroscopy.

African Masks: Are They Authentic Of Fake? A Fluorescence And Reflective Uv-Vis Spectroscopic Approach, Kaitlyn Parrott

Fall 2018 - Chemical Analysis Class Projects

This project was a search for a new way to determine the authenticity of their African Mask collection. The University of Northern Iowa Museum has allowed the non-destructive analysis of five of their African Masks and a collection of African wood samples. This study is investigating if fluorescence spectroscopy and reflective UV-Vis spectroscopy of the African masks Of the five masks two are authentic masks, two are fake, and one the authenticity is unknown.

Exploration Of Potential Treatments Of Bronze Disease Through Sem/Edx Analysis, Nicole Bishop, Brian Pauley

Fall 2018 - Chemical Analysis Class Projects

The poster shows a potential treatment for the corrosion of bronze objects.

Photocatalytic Degradation Of Simazine Using Zno/Go Composites, Kenneth Ray Flores

Theses and Dissertations

The photocatalytic degradation of simazine (SIM) by Zinc oxide/graphene oxide (ZnO/GO) composites, under visible light irradiation, was investigated to determine various reaction parameters, of initial pH, ZnO loading on GO, and catalyst mass. A pH of 2 was determined to be the optimal reaction pH for all ZnO/GO catalysts. A loading mass of 40mg for the 20 & 30mmol composites; whereas a 10mg mass was determined to be most effective for the 10mmol composite. The reaction followed second order kinetics for the degradation process, the reaction dependence was determined to be on the concentration of SIM in solution. All ZnO/GO …

Community-Based Research Methods To Inform Public Health Practice And Policy: The Case Of Lead In The Mississippi Delta, Mary Alexandra Fratesi

Honors Theses

Environmental health issues are complex and require interdisciplinary and community engagement approaches to better understand them and inform policy. As one example, lead exposure has a number of dangerous neurological effects, including developmental delays and learning deficits. Potential lead exposure through drinking water and paint are areas of concern. In a 2018 document, the Environmental Protection Agency (EPA) estimated that up to 20% of lead exposure comes from drinking water alone. By using a type of engagement research called community-based research (CBR), this project began to address this major public health issue. CBR can be used to connect residents, their …

Vitamin E Promotes The Inverse Hexagonal Phase Via A Novel Mechanism Implications For Antioxidant Role, Paul Harper

University Faculty Publications and Creative Works

No abstract provided.

Oxidation Of Carbon Monoxide Over Ceria And Alumina Supported Palladium Catalysts, John Davis Gary

Theses and Dissertations

Palladium catalysts on both Al2O3 and CeO2, supports were studied for efficacy in low temperature carbon monoxide oxidation. Calcination temperatures were varied between 500-900°C for alumina supported catalysts and shown to have no significant difference in activity. X-Ray Photoelectron Spectroscopy studies revealed structural changes associated with palladium states and reacted catalysts and displayed a change from palladium oxide (PdO) to native palladium oxide (PdOx) and elemental palladium (Pd). Activity studies were conducted on all catalysts synthesized and indicated that Pd/Al2O3 achieved 100% CO conversion at 150°C when calcined at 500°C and pretreated with reduction process. Pd/CeO2 showed higher activity and …

Heteroleptic Nickel Complexes Of A Bulky Bis(Carbene)Borate Ligand, Jorge L. Martinez, Wei-Tsung Less, Maren Pink, Chun-Hsing Chen, Jeremy M. Smith

Chemistry: Faculty Publications and Other Works

Bis(carbene)borate ligand transfer to the nickel nitrosyl synthon Ni(NO)(PPh3)2Br provides the new nickel nitrosyl complex Ph2B(t BuIm)2Ni(NO)(PPh3). The solid state structure reveals a trigonal pyramidal nickel ion with a very long bond to the apical PPh3 ligand. The complex reversibly dissociates PPh3 in solution to afford three‐coordinate Ph2B(t BuIm)2Ni(NO), with NMR data providing evidence for PPh3 binding at low temperatures. Ligand transfer to Ni(PMe3)2Cl2 provides the square planar complex, Ph2B(t BuIm)2Ni(PMe3)Cl, which shows no evidence for rearranging to the form a homoleptic complex with two bis(carbene)borate ligands. This complex is a suitable synthon for the [Ph2B(t BuIm)2Ni]+ fragment, as demonstrated …