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Manipulating The Optical Properties Of Hollow Pd/Ag And Pt/Ag Nanoparticles Synthesized By Galvanic Replacement Reaction, Salvador Alcantar 2017 Governors State University

Manipulating The Optical Properties Of Hollow Pd/Ag And Pt/Ag Nanoparticles Synthesized By Galvanic Replacement Reaction, Salvador Alcantar

All Capstone Projects

Considerable efforts have recently been devoted to the fabrication of metallic nanostructures on account of their tunable morphologies which can lead to new and fascinating optical properties. These properties of a metallic nanostructure are most determined by their size, shape, composition and structure. Hollow metallic nanostructures have attracted much interest as their surface plasmonic properties and catalytic activities are completely different from those of solid nanoparticles. Galvanic replacement reaction (GRR) was known to be a powerful synthetic technique for converting solid metal nanostructures into hallow ones. These hollow nanostructures have high specific surface area, low density, use less material and ...


Synthesis Of Au/Ag, Pd/Ag And Pt/Ag Nanoparticles By Galvanic Replacement Reaction, Sunnith Kumar Admala 2017 Governors State University

Synthesis Of Au/Ag, Pd/Ag And Pt/Ag Nanoparticles By Galvanic Replacement Reaction, Sunnith Kumar Admala

All Capstone Projects

In recent years, galvanic replacement reactions have been successfully employed to produce bimetallic nanoparticles of a range of shapes, yet to date very few efforts have been devoted to develop methods for synthesizing smaller (<10nm) M/Ag; M=Au, Pt, Pd alloy particles using Ag hollow particles as sacrificial template. In this research work, we investigated new approach for the controllable synthesis of Au/Ag, Pd/Ag, and Pt/Ag alloy nanoparticles by applying galvanic replacement reaction on hollow Ag template in the presence of gold, palladium, and platinum salts. According to TEM analysis, the sizes of Au/Ag, Pd/Ag, and Pt/Ag alloy particle are 7.0±1.6 nm, 6.0±1.2 nm, and 3.0±0.8 nm, respectively. According to the study of optical property measurements on Ag hollow samples with increasing Au, Pt, and Pd content, it was observed that surface plasmon resonance peaks of the Au/Ag particles prepared with higher concentrated HAuCl4 solutions absorb at longer wavelengths and are red-shifted compared to the surface plasmon resonance of Ag hollow template. In the case of adding K2PdCl4 to Ag hollow sample resulted in blue shift of surface Plasmon resonance peaks for initial addition of palladium salt and further addition of K2PdCl4 caused the Plasmon peaks to diminish. Interestingly, our attempt to make Pt/Ag particle by reacting Ag hollow particles with various amounts of K2PtCl4 revealed that resulting alloy particles could still exhibit surface Plasmon resonance peaks for higher Pt content. Usually Pt and Pd nanoparticles do not exhibit surface plasmon resonance peaks in the visible spectrum. This work provides a model for a design of M/Ag; M=Au, Pt, Pd alloy particles, where combining Ag hollow samples with increasing amounts of Au, Pt, and Pd can provide successful execution of tenability of surface plasmon resonance.


Preparation Of Au/Ag Nanoshells Through A Galvanic Replacement Reaction, Elizabeth Maschmeyer 2017 Governors State University

Preparation Of Au/Ag Nanoshells Through A Galvanic Replacement Reaction, Elizabeth Maschmeyer

All Capstone Projects

It generally requires solid metal templates of hollow metal structures with uniform morphology by the present galvanic replacement mediated-growth approaches. In this project report, we present a new and simple approach for the controllable synthesis of Au/Ag alloy nanoshells (NSs) by applying galvanic replacement reaction on hollow Ag template in the presence of gold salt. High quality thiol-coated spherical shape Au/Ag NSs were produced via this new synthetic approach and the hollow interior of the Ag template is very well preserved during the galvanic replacement reaction. Plasmonic property measurements reveal that Au/Ag NSs exhibit strong absorption peak ...


Detection Of Tetracyclines In An Anaerobic Waste Digester Using Solid Phase Extraction And High-Performance Liquid Chromatography Mass Spectrometry, Courtney Cruse 2017 Western Kentucky University

Detection Of Tetracyclines In An Anaerobic Waste Digester Using Solid Phase Extraction And High-Performance Liquid Chromatography Mass Spectrometry, Courtney Cruse

Honors College Capstone Experience/Thesis Projects

Antibiotics are introduced to livestock to encourage growth and for the treatment of diseases. These antibiotics are not completely metabolized by swine, and thus these antibiotics are excreted with their waste. This poses a potential risk to human health as these antibiotics, a potential link to antibiotic resistant bacteria, then enter the surface water, ground water, and soil. In collaboration with the US Department of Agriculture (USDA) in Bowling Green, Kentucky, this research is concerned with analyzing the degradation of tetracyclines in swine waste from an anaerobic digester. Waste samples obtained from a digester and swine waste at the USDA ...


Investigation Of The Chemical Interface In The Soybean–Aphid And Rice–Bacteria Interactions Using Maldi-Mass Spectrometry Imaging, Adam T. Klein, Gargey B. Yagnik, Jessica D. Hohenstein, Zhiyuan Ji, Jiachen Zi, Malinda D. Reichert, Gustavo C. Macintosh, Bing Yang, Reuben J. Peters, Javier Vela, Young Jin Lee 2017 Iowa State University

Investigation Of The Chemical Interface In The Soybean–Aphid And Rice–Bacteria Interactions Using Maldi-Mass Spectrometry Imaging, Adam T. Klein, Gargey B. Yagnik, Jessica D. Hohenstein, Zhiyuan Ji, Jiachen Zi, Malinda D. Reichert, Gustavo C. Macintosh, Bing Yang, Reuben J. Peters, Javier Vela, Young Jin Lee

Reuben J. Peters

Mass spectrometry imaging (MSI) is an emerging technology for high-resolution plant biology. It has been utilized to study plant–pest interactions, but limited to the surface interfaces. Here we expand the technology to explore the chemical interactions occurring inside the plant tissues. Two sample preparation methods, imprinting and fracturing, were developed and applied, for the first time, to visualize internal metabolites of leaves in matrix-assisted laser desorption ionization (MALDI)-MSI. This is also the first time nanoparticle-based ionization was implemented to ionize diterpenoid phytochemicals that were difficult to analyze with traditional organic matrices. The interactions between rice–bacterium and soybean ...


Evolution Of Cu2o Morphology During Copper Corrosion In The Presence Of Gamma-Radiation, Arielle M. Jean 2017 The University of Western Ontario

Evolution Of Cu2o Morphology During Copper Corrosion In The Presence Of Gamma-Radiation, Arielle M. Jean

Electronic Thesis and Dissertation Repository

In this work, experiments were carried out in order to develop a mechanistic understanding of the corrosion of copper metal in limited water volumes under gamma-radiation. When exposed to gamma-radiation, water decomposes into chemically reactive oxidizing and reducing species. Under a continuous radiation flux, the concentrations of the radiolytically produced oxidants eventually reach a pseudo-steady state that can influence the corrosion kinetics of metallic surfaces.

The evolution of the surface morphology during water droplet corrosion of copper in the presence of gamma-radiation was investigated as a function of irradiation time and pH. The oxide growth kinetics were studied by measuring ...


Evaluation Of A Filtration Sorbent For Remediation Of Arsenic In Groundwater, Clement Do 2017 California State University - San Bernardino

Evaluation Of A Filtration Sorbent For Remediation Of Arsenic In Groundwater, Clement Do

Electronic Theses, Projects, and Dissertations

A commercially available product, PURA PhosLock, was identified and evaluated for use as a sorbent to remove dissolved arsenic (As) from drinking water. Although marketed as a product to remove phosphate in aquaria, it is composed of iron oxide hydroxide (i.e., FeO(OH)), which is also known to adsorb dissolved As species from water. Arsenic was measured using standard methods and Graphite Furnace Atomic Absorption Spectroscopy. A first rough filtration test was performed to see if the PhosLock adsorbed As well. About 50 g of PhosLock was used to filter 10 L of tap water containing 100 ppb As ...


Apparent Retention Volume Variation With Flow Rate Change In High Performance Liquid Chromatography, Susanne Buntz Erz 2017 Seton Hall University

Apparent Retention Volume Variation With Flow Rate Change In High Performance Liquid Chromatography, Susanne Buntz Erz

Seton Hall University Dissertations and Theses (ETDs)

Recent studies have demonstrated noticeable flow rate dependency of the chromatographic zone retention volume with respect to migration within the empty capillary. This appears to be the result of superposition of asymmetric lateral diffusion and of the laminar flow profile. Although these effects have been studied on empty capillaries, in the presence of the packed column, the retention shift may be insignificant relative to the adsorption-based retention of the analytes. In the case of fast and ultrafast HPLC with short capillary columns, the effect of extra-column caused variation in the analyte retention may constitute an increase of up to 120 ...


Study Of Selectivity In Extraction, Separation, And Detection On Drugs Using Gas Chromatography, Anumeha P. Muthal 2017 Seton Hall University

Study Of Selectivity In Extraction, Separation, And Detection On Drugs Using Gas Chromatography, Anumeha P. Muthal

Seton Hall University Dissertations and Theses (ETDs)

The selectivity of a method is defined by its ability to determine a particular analyte without interference in a complex mixture. Selectivity in gas chromatography (GC) can be obtained at different points in the analysis including the sample preparation, sample introduction, separation on column and detection. In GC, the first dimension of selectivity can be obtained in sample preparation; the second dimension in chromatographic separation and the third dimension in detection. This research focuses on the relationships between selectivity in these different dimensions, studied using some non-steroidal anti-inflammatory drugs, glucocorticoids, fatty acid methyl esters and polycyclic aromatic hydrocarbons. Recent methodologies ...


Ion-Ion Dual-Electrospray Chemistry, Tyler D. Schriber 2017 University of Wyoming

Ion-Ion Dual-Electrospray Chemistry, Tyler D. Schriber

Honors Theses AY 16/17

The research that I have performed since the Spring 2016 semester is based on a study done by Cotham et al. in 2015, where front-end sprayers are used to mix solutions before they enter a mass spectrometer. One of these solutions contains a peptide, which is positively charged, and the other solution contains the reagent 4-formyl-1,3-benzenedisulfonic acid (FBDSA), which is negatively charged. The charges lead to a reaction in microseconds, with spray droplets, before it enters the instrument. Once inside the mass spectrometer a technique called collision induced dissociation (CID) is implemented in order to completely combine the reactant ...


Functionalized Silica Gel For Adsorption Of Cesium From Solution, Kenneth Marshall Seaton III 2017 East Tennessee State University

Functionalized Silica Gel For Adsorption Of Cesium From Solution, Kenneth Marshall Seaton Iii

Electronic Theses and Dissertations

Mesoporous silica gel containing embedded phosphotungstic acid (PTA) was synthesized by sol-gel co-condensation of tetraethyl orthosilicate with PTA in acidic media. The obtained material had high Brunauer-Emmett-Teller Theory (BET) surface area and pore volume. A characteristic band of the Keggin structure of PTA was present in its FT-IR spectrum while its X-ray diffraction patterns were absent. This proved the embedding of PTA on a sub-molecular level and not as a second phase. Acidic sites were determined by neutralization with base in aprotic solvent, followed by titration of the remaining base with an acid. The material demonstrated high adsorption capacity of ...


Phosphomolybdic Acid Catalysis Of Cellulose Hydrolysis, Troy R. Dolmetsch 2017 East Tennessee State University

Phosphomolybdic Acid Catalysis Of Cellulose Hydrolysis, Troy R. Dolmetsch

Undergraduate Honors Theses

Renewable sources such as cellulose derived biofuels are sought after in order to replace fossil fuel sources that are currently used to meet energy demands. Cellulose is a biological polymer composed of a chain of glucose molecules. Hydrolysis of cellulosic materials then has potential to serve as a source of renewable energy in the form of biofuels. The crystalline structure of cellulose is very stable, and current methods of catalyzed hydrolysis are inefficient for industrial application. This project explores the use of phosphomolybdic acid (PMA) in water to catalyze hydrolysis of microcrystalline cellulose. Temperature of hydrolysis was varied from 40 ...


Fundamental Studies Of Metal Ion Extraction Into Ionic Liquids By Macrocyclic Polyethers, James Lee Wankowski 2017 University of Wisconsin-Milwaukee

Fundamental Studies Of Metal Ion Extraction Into Ionic Liquids By Macrocyclic Polyethers, James Lee Wankowski

Theses and Dissertations

The liquid-liquid extraction (LLX) of metal ions from aqueous media into ionic liquids (ILs) by macrocyclic polyethers has proven to be an efficient and selective, but complex approach to their separation. Partitioning in these systems has previously been described using a so-called ‘three-path’ model comprising three distinct extraction pathways: neutral complex / ion pair extraction, exchange of the IL cation for a metal-extractant complex, and exchange of the metal ion for a hydronium ion bound to the extractant. The balance of these three paths has been reported to be affected by several characteristics of the LLX system, including the structure of ...


Homogeneous Ligand-Centered Hydrogen Evolution And Hydrogen Oxidation : Exploiting Redox Non-Innocence To Drive Catalysis., Andrew Z. Haddad 2017 University of Louisville

Homogeneous Ligand-Centered Hydrogen Evolution And Hydrogen Oxidation : Exploiting Redox Non-Innocence To Drive Catalysis., Andrew Z. Haddad

Electronic Theses and Dissertations

Hydrogen is a promising carbon-free fuel / energy carrier and is an essential building block for many industrial and agricultural processes. Rising energy demands have ignited interest in the development of carbon-free and carbon neutral energy sources. In this context, hydrogen is an attractive candidate—being energy-dense, carbon-free—and easily accessible through a two-electron reduction of water. Accordingly, many electrochemical homogeneous catalyst systems have been studied, with a focus on understanding the mechanism of hydrogen evolution proceeding through metal-hydride intermediates. However, there has been a renaissance in hydrogen evolution reaction (HER) catalyst design, with many groups implicating ligand redox non-innocence as ...


An Electrochemical Characterization Of A Vanadium-Based Deoxydehydration Catalyst, Joel Eric Baker 2017 University of Arkansas, Fayetteville

An Electrochemical Characterization Of A Vanadium-Based Deoxydehydration Catalyst, Joel Eric Baker

Theses and Dissertations

Alternative methods for the conversion of polyols into olefins, be it for carbon storage or hydrocarbon fuel production, have become prevalent in today’s chemical industry. One process in particular, deoxydehydration (DODH) has been proven effective in taking sustainable biomass derivatives and converting them through the utilization of various homogenous metal catalysts. While this process may show productive yields and material conversion, it is hindered by the need of a sacrificial reductant. This makes a novel process economically unviable and relatively unused outside of scientific research. That fact begs the question: Can the process be improved? It is proposed here ...


The “Apparent” Diffusion Coefficient Of Electrons Through A Nafion Membrane, Marissa Kayle Reynolds 2017 University of Arkansas, Fayetteville

The “Apparent” Diffusion Coefficient Of Electrons Through A Nafion Membrane, Marissa Kayle Reynolds

Theses and Dissertations

The hydrogen/oxygen fuel cell is a greener, more efficient energy solution. However, there are many problems with the fuel cell including storage, infrastructure, cost, the oxygen reduction reaction, and the durability of the proton exchange membrane (PEM). The PEM is not only used as the electrolyte for the cell but also as a physical barrier between the anode and the cathode. The integrity of this membrane is crucial to the functioning of the fuel cell. This thesis will examine using ferricyanide as a probe molecule for diagnostic experiment of Nafion membrane integrity. Using hydrodynamic voltammetry with a rotating disk ...


Electrochemical Time Of Flight For Rapid And Direct Measurement Of Diffusion Coefficients, Jonathan C. Moldenhauer 2017 University of Arkansas, Fayetteville

Electrochemical Time Of Flight For Rapid And Direct Measurement Of Diffusion Coefficients, Jonathan C. Moldenhauer

Theses and Dissertations

The determination of diffusion coefficients is of fundamental importance to the understanding of electrochemistry and sensors. Developing a method by which diffusion coefficients of Red/ox active analytes can be determined quickly and elegantly, would be a great advancement over presently accepted methods. This dissertation reports the reviving electrochemical time of flight (ETOF), and developing a method that allows for empirical determination of diffusion coefficients from a single measurement. ETOF is a generate and detect experiment where the time an electrochemically generated species takes to transit a known distance is measured and related to the diffusion coefficient of the species ...


Improved Sample Utilization In Thermal Ionization Mass Spectrometry Isotope Ratio Measurements: Refined Development Of Porous Ion Emitters For Nuclear Forensic Applications, Matthew Louis Baruzzini 2017 University of Tennessee, Knoxville

Improved Sample Utilization In Thermal Ionization Mass Spectrometry Isotope Ratio Measurements: Refined Development Of Porous Ion Emitters For Nuclear Forensic Applications, Matthew Louis Baruzzini

Doctoral Dissertations

The precise and accurate determination of isotopic composition in nuclear forensic samples is vital for assessing origin, intended use and process history. Thermal ionization mass spectrometry (TIMS) is widely accepted as the gold standard for high performance isotopic measurements and has long served as the workhorse in the isotopic ratio determination of nuclear materials. Nuclear forensic and safeguard specialists have relied heavily on such methods for both routine and atypical efforts. Despite widespread use, TIMS methods for the assay of actinide systems continue to be hindered by poor ionization efficiency, often less than tenths of a percent; the majority of ...


Enzyme Kinetics Studies To Guide Mathematical Modeling Of Microdialysis Sampling To Predict In Situ Biochemistry, Justin M. Klucher 2017 University of Arkansas, Fayetteville

Enzyme Kinetics Studies To Guide Mathematical Modeling Of Microdialysis Sampling To Predict In Situ Biochemistry, Justin M. Klucher

Chemistry & Biochemistry Undergraduate Honors Theses

Microdialysis is a diffusion-based sampling method that can be useful for monitoring various biological systems. Matrix metalloproteinases are a class of enzymes responsible for remodeling the extracellular matrix that, when dysregulated, are linked to various diseases. The delivery method of microdialysis is of particular interest as a sampling technique for enzymatic reactions. Microdialysis was performed in vitro using a model enzyme, porcine pancreatic elastase, because it is a useful substitute for matrix metalloproteinases. A colorimetric substrate for elastase, succinyl-ala-ala-ala-p-nitroanilide, and its product p-nitroaniline were measured using a UV-Vis spectrophotometer. Using an expanded Beer’s Law equation, both analytes’ concentrations were ...


Metalation And Structural Properties Of Apo-Metallothioneins, Gordon W. Irvine 2017 The University of Western Ontario

Metalation And Structural Properties Of Apo-Metallothioneins, Gordon W. Irvine

Electronic Thesis and Dissertation Repository

Metals are required by a quarter of all proteins to achieve their biological function, whether in an active site involved in catalytic chemistry or in a structural capacity. Metals are tightly regulated at the cellular level due to their propensity to cause unwanted side reactions and to be scavenged for use by pathogens. One of the proteins involved in this regulation of metal homeostasis is metallothionein (MT) which is a small, cysteine rich protein primarily involved in the regulation of zinc and copper homeostasis and heavy metal detoxification. MT is unique in its high cysteine content (~30% of the residues ...


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