Physical Sciences and Mathematics Commons^™

Stability Of Group Four Monochalcogenides In Water And Air, William Shattuck

Graduate Theses and Dissertations

Previously published works have simulated the behavior of monolayer group IV monochalcogenides and predicted them to have very useful electronic properties. These simulations have also predicted that monolayers of group IV monochalcogenides will degrade quickly when exposed to water, even in extremely low concentrations. We hypothesize that thin samples of these materials will show signs of degradation if left in air and in water for an extended period of time.

Samples of each of the four monochalcogenides (GeS, GeSe, SnS and SnSe) were exfoliated onto clean oxidized silicon substrates. Chemical analysis showed the SnSe samples were contaminated, so they were …

Synthesis, Characterization, And Kinetics Studies Of New Cobalt Complexes For The Production Of H2 In Acidic Media, Michael John Celestine

Chemistry & Biochemistry Theses & Dissertations

The kinetics and mechanism of the oxidation of [Co(dmgBF₂)₂(OH₂)₂] (where dmgBF₂ = difluoroboryldimethylglyoximato) by sodium hypochlorite (NaOCl), sodium bromate (NaBrO₃), and bromine (Br₂₎ was investigated by stopped-flow spectrophotometry at 450 nm over a wide temperature range. The pK_a1 value for [Co(dmgBF₂)₂(OH₂)₂] was calculated as 5.27 ± 0.14 at I = 0.60 (NaCl). From the variation in pH studies, the activation parameters were derived from the proposed mechanisms for NaOCl, ΔH_1*, ΔH_2*, ΔS_1*, and …

Oxidation Of Phenolic Aldehydes By Ozone And Hydroxyl Radicals At The Air-Water Interface, Md Sohel Rana, Marcelo I. Guzman

Chemistry Faculty Publications

Biomass burning releases highly reactive methoxyphenols into the atmosphere, which can undergo heterogeneous oxidation and act as precursors for secondary organic aerosol (SOA) formation. Understanding the reactivity of such methoxyphenols at the air–water interface is a matter of major atmospheric interest. Online electrospray ionization mass spectrometry (OESI-MS) is used here to study the oxidation of two methoxyphenols among three phenolic aldehydes, 4-hydroxybenzaldehyde, vanillin, and syringaldehyde, on the surface of water. The OESI-MS results together with cyclic voltammetry measurements at variable pH are integrated into a mechanism describing the heterogeneous oxidative processing of methoxyphenols by gaseous ozone (O₃) and …

The Statue Of Liberty Laboratory Activity: The Chemistry Of Copper, Jihyun Kim, Marcus D. Allen

Open Educational Resources

In this lab activity we observe chemical changes of copper in acidic conditions, salt water, and a mixture of lemon juice and vinegar and salt, and we discuss whether the Statue of Liberty would hold as much cultural icon today had the Lady Statue remain the original shiny brown color.

Approaches Towards The Synthesis Of Ketamine Metabolites, Ann K. Patrick

Honors Theses

Major Depressive disorder (MDD) plagues society and stands at the forefront of research as MDD affects approximately 16% of the population. Pharmaceutical drugs, including the selective serotonin reuptake inhibitors (SSRIs), have been used for MDD treatment and remain a popular option today. However, current antidepressant treatments have proven to be ineffective in just less than half of the patients. Research continues with the goal to better understand the mechanisms of the pathology of depression and to search for other treatment options. For example, the stress-neurogenesis hypothesis investigates the role of stress and decreased neuroplasticity within MDD.

Supporting the stress-neurogenesis hypothesis, …

Ferrate(Vi) For Wastewater Treatment : Phosphorus Removal, Lei Zheng

Theses, Dissertations and Culminating Projects

Phosphorus (P) is a major nutrient present in municipal wastewater. Without proper treatment and management, residual P in treated wastewater finally enters into natural receiving water bodies. Nutrient pollution resulting from excessive P, together with the other nutrient, i.e. nitrogen (N), is a leading cause of eutrophication, a ubiquitous U.S. water quality issue. An overgrowth of algae during eutrophication brings extremely adverse impacts on the water quality. The algal bloom can rapidly deplete dissolved oxygen, lead to the death of aquatic life, increase water turbidity, and cause taste and odor issues. Moreover, some harmful algal boom can produce toxins to …

Brown Carbon Production By Aqueous-Phase Interactions Of Glyoxal And So2, David O. De Haan, Kevin Jansen, Alec D. Rynaski, W. Ryan P. Sueme, Ashley K. Torkelson, Eric T. Czer, Alexander K. Kim, Michael A. Rafla, Audrey C. De Haan, Margaret A. Tolbert

Chemistry and Biochemistry: Faculty Scholarship

Oxalic acid and sulfate salts are major components of aerosol particles. Here, we explore the potential for their respective precursor species, glyoxal and SO₂, to form atmospheric brown carbon via aqueous-phase reactions in a series of bulk aqueous and flow chamber aerosol experiments. In bulk aqueous solutions, UV- and visible-light-absorbing products are observed at pH 3–4 and 5–6, respectively, with small but detectable yields of hydroxyquinone and polyketone products formed, especially at pH 6. Hydroxymethanesulfonate (HMS), C₂, and C₃ sulfonates are major products detected by electrospray ionization mass spectrometry (ESI-MS) at pH 5. Past studies …

Green Chemistry: The Oxidation Of Benzaldehyde Using Atmospheric Oxygen And N-Heterocyclic Carbenes As Catalysts, Alex Brody, John Morgan

Student Research Poster Presentations 2020

Oxidation is a vital process in organic and biochemical reactions. In particular, the oxidation of aromatic aldehydes to carboxylic acids and esters is a vital process used in many different environments. Benzaldehyde is one common subject of this type of reaction, used in the synthesis of benzoic acid and benzoate derivatives. Unfortunately, the industrial synthesis of these compounds uses harmful heavy metal oxidants such as Chromium(VI) and Manganese(VII), which are very harmful to the environment. We proposed to eliminate these pollutants by using atmospheric oxygen and an organic catalyst in a solvent free reaction. This reaction would then be microwaved …

Carbon Oxidation At The Atomic Level: A Computational Study On Oxidative Graphene Etching And Pitting Of Graphitic Carbon Surfaces, Simon Schmitt

Theses and Dissertations--Mechanical Engineering

In order to understand the oxidation of solid carbon materials by oxygen-containing gases, carbon oxidation has to be studied on the atomic level where the surface reactions occur. Graphene and graphite are etched by oxygen to form characteristic pits that are scattered across the material surface, and pitting in turn leads to microstructural changes that determine the macroscopic oxidation behavior. While this is a well-documented phenomenon, it is heretofore poorly understood due to the notorious difficulty of experiments and a lack of comprehensive computational studies. The main objective of the present work is the development of a computational framework from …

Electron Tunneling And X-Ray Photoelectron Spectoscopy Studies Of The Superconductiong Properties Of Nitrogen-Doped Niobium Resonator Cavities, Eric M. Lechner, Basu Dev Oli, Junki Makita, Gianluigi Ciovati, Alex Gurevich, Maria Iavarone

Physics Faculty Publications

We use scanning tunneling microscopy (STM) and spectroscopy (STS), and x-ray photoelectron spectroscopy (XPS) to investigate the effect of nitrogen doping on the surface electronic and chemical structures of cutouts from superconducting Nb radio-frequency cavities. The goal of this work is to get insights into the fundamental physics and materials mechanisms behind the striking decrease of the surface resistance with the radio-frequency magnetic field, which has been observed on N-doped Nb cavities. Our XPS measurements reveal significantly more oxidized Nb 3d states and a thinner metallic suboxide layer on the N-doped Nb surfaces, which is also confirmed by tunneling spectroscopy …