Physical Chemistry Commons^™

Electrochemical Voltammetric Behavior Of Sulfur Mustard On The Bare Pt Electrode, Yu-Lin Yang, Jie Sun, Tian Zhou, Ji-Gang Li, Shou-Ping Wei

Journal of Electrochemistry

The sulfur mustard (bis(2-chloroethyl) sulphide, HD), one of highly toxic chemical weapon agents, can damage the alive tissue cells (such as skin, lung, respiratory mucosa and so on), and cause carcinogenic and mutagenic effects for a long time exposure, which imposes a great threat not only to the human health, but also to the sustainable development of the society. With its convenience, high sensitivity and rapid response, electrochemical technology exhibits considerable potential in the field-deployed detection toward HD, but the related reports are rare. Herein, the electrochemical behavior of HD on the bare Pt electrode was investigated by electrochemical measurements, …

Electrocatalytic "Volcano-Type" Effect Of Nano-Tio2 (A)/(R) Phase Content In Pt/Tio2-CnX Catalyst, Ai-Lin Cui, Yang Bai, Hong-Ying Yu, Hui-Min Meng

Journal of Electrochemistry

The relationship between the electrochemical activity of fuel cell catalysts and Pt particle size, as well as the catalyst support and co-catalyst is still unclear. In this work, FESEM, XRD, BET, TEM and CV techniques were adopted to investigate the effects of TiO₂ anatase (A)/rutile (R) phases content on the electrochemical activity of Pt electrocatalyst. The results showed that the anatase-rutile phase transformation occurred during the heat treatment of TiO₂ at 700 ~ 900 ^oC accompanied by the growth of two-phase crystalline size, and anatase was completely transformed into rutile at 900 ^oC. TEM results revealed …

Biofouling Behaviors Of Pure Titanium Surface Polarized At Different Potentials, Zhao-Xia Dai, Da-Jiang Zheng, Guang-Ling Song, Dan-Qing Feng, Pei Su

Journal of Electrochemistry

Titanium (Ti) and its alloys are commonly used as engineering materials. Although they have been widely used in marine environments, they are also facing serious threats of biofouling. Therefore, it is necessary to investigate the relationship between electrochemical behavior and bioaffinity of titanium oxide film in seawater to explore effective surface treatment technology to reduce biofouling. In this work, the cathodic potential of -0.8 V_SCE and the passivation potential of 0.5 V_SCE were directly applied to the TA2 Ti in artificial seawater for potentionstatic polarization treatment to prepare two kinds of surface films with different states and then …

Effect Of Chloride Ion On Electrochemical Behavior Of Silver Electrodeposition In Chcl-Urea Low Eutectic Solvent, Chong-Bo Zhan, Run-Jia Zhang, Xu Fu, Hai-Jing Sun, Xin Zhou, Bao-Jie Wang, Jie Sun

Journal of Electrochemistry

Metallic silver coating has been widely used in the fields of microelectronics industry, catalyst, sensor and preparation of magnetoresistive materials because of its excellent corrosion resistance, good lubricity, high conductivity, excellent decoration and high catalysis. Compared with the traditional aqueous solution system, the research on metal electrodeposition in ionic liquid system is developing rapidly. In addition, additives are the key factors in the silver plating process. Adding a small amount of organic or inorganic additives to the plating solution will significantly change the coating properties, such as improving brightness, hardness and ductility. In this paper, using choline chloride urea (ChCl-Urea) …

Study And Improvement On Expansion Property Of Silicon Oxide, Wei-Chuan Qiao, Fang-Ru Li, Jin-Lin Xiao, Li-Juan Qu, Xiao Zhao, Meng Zhang, Chun-Lei Pang, Zi-Kun Li, Jian-Guo Ren, Xue-Qin He

Journal of Electrochemistry

The silicon-based anode materials have the potential to meet the ever-increasing demand for energy density in lithium-ion batteries market owing to their high theoretical specific capacity. Unfortunately, their commercialization was hindered by the continuous volume expansion. Herein, the expansion characteristics and corresponding mechanism of the silicon oxide and graphite-silicon oxide composites were investigated by in-situ displacement detection systematically. The results showed that the expansion property was improved by material process modifications. During the de/lithiation processes of graphite, the expansion ratio in 30% ~ 50% SOC changed little because of the small interlayer spacing variation of the intercalated graphite. …

Preparation And Properties Of Gcp-Supported Palladium Particles Composite Towards Electrochemical Ammonia Synthesis, Ying-Chao Wang, Zi-Zai Ma, Yi-Fan Wu, Xiao-Guang Wang

Journal of Electrochemistry

Ammonia (NH₃) plays an essential role in agriculture and modern industries. Electrochemical fixation of nitrogen (N₂) to ammonia (NRR) under ambient conditions with renewable electricity is a promising strategy to replace the industrial Haber-Bosch method. However, it usually suffers from extremely poor ammonia yield and low Faraday efficiency due to the poor electrocatalysts. Therefore, intensive studies have been devoted to developing efficient NRR catalysts till now. Among them, palladium (Pd) can capture protons in the aqueous phase to form stable α-PdH, which balances the competitive adsorption between nitrogen and protons as well as reduces the …

Simultaneous Hydrogen And (Nh4)2So4 Productions From Desulfurization Wastewater Electrolysis Using Mea Electrolyser, Ju-Cai Wei, Lin Shi, Xu Wu

Journal of Electrochemistry

It is preferred to simultaneously recover resource and energy from waster. Sulfur dioxide, SO₂, a common air pollutant, a potential energy resource, is a key link to sulfur nature circulation. SO₂ can be conversed to NH₄HSO₃ and (NH₄)₂SO₃ during the ammonia desulfurization process, which can be used to produce (NH₄)₂SO₄ fertilizer. For high quality (NH₄)₂SO₄ fertilizer and high heat transfer efficiency of the evaporative crystallization, HSO₃^- or SO₃^2- needs to be oxidized to form SO …

A New Insight Into Fungal Cell Wall Architecture By Functional Genomics And Solid-State Nmr Along With Recent Advancements In Dynamic Nuclear Polarization For Analyzing Biomolecules, Arnab Chakraborty

LSU Master's Theses

This dissertation summarizes the findings related to the way by which supramolecular architecture of fungal cell wall changes with genetic mutation, dispensing genes responsible for biosynthesis of cell wall polysaccharides. This is necessary because without perfect picture of how supramolecular assembly changes with genetic mutation it is hard to assess new anti-fungal targets. Alongside this we have highlighted how recent advancement into Dynamic Nuclear Polarization (DNP) methods improved characterization of biomolecules both in case of labeled and unlabeled samples.

First study utilized Solid-state NMR (SSNMR) which is a non-destructive technique hence enabled us for the first time to deduce how …

Monitoring Bacteria Cultures Using Near Infrared (Nir) Binary Spectronephelometry (Bsn), Raman Spectra And Principal Component Analysis (Pca), Steven Ortiz

Dissertations - ALL

Current noninvasive methods cannot continuously and simultaneously monitor the concentrations of cells and media components that define the state of native bacterial cultures, because of changing turbidity. A new technique, binary spectronephelometry (BSN) has the same or better sensitivity and precision for population monitoring as optical density at 600nm (OD600), while simultaneously measuring metabolic processes. The BSN algorithm uses laser induced emission to probe mildly turbid media i.e., propagation of light occurs in the single scattering regime. A BSN "training set" associates a grid of elastic emission measurements, comprising Rayleigh and Mie scattering, and inelastic emission measurements, comprising fluorescence and …

Insights Into Molecular Recognition And Reactivity From Molecular Simulations Of Protein-Ligand Interactions Using Md And Qm/Mm, Jerrano L. Bowleg

Theses and Dissertations

In this thesis, we have employed two computational methods, molecular dynamics (MD) and hybrid quantum mechanics/molecular mechanics (QM/MM) MD simulations with umbrella sampling (US), to gain insights into the molecular mechanism governing the molecular recognition and reactivity in several protein-ligand complexes. Three systems involving protein-ligand interactions are examined in this dissertation utilizing well-established computational methodologies and mathematical modeling. The three proteins studied here are acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN1). These enzymes are known to interact with a variety of ligands. AChE dysfunction caused by organophosphorus (OP) chemicals is a severe hazard since AChE is …

Lc-Ms Identification Of Serum Proteins Adsorbed Onto Ionic Liquid-Coated Nanoparticles, Anh M. Hoang

Honors Theses

Nanocarriers are promising candidates for drug delivery due to their size and tunable surface characteristics. However, when they are intravenously injected, few particles make it to their designated location. This is because upon entering the bloodstream, the serum in the blood, which is rich with a diversity of proteins, adsorbs onto the particles’ surfaces forming a protein corona. Many of the attached proteins trigger the mobile immune system and are removed by macrophages, and many particles are then filtered out by the liver and kidneys. Ionic Liquids (ILs), which consist of asymmetric, bulky components that are liquid

A Study Of Cannabigerolic Acid And Its Derivatives Via Raman Spectroscopy And Density Functional Theory, Trevor Wolfe

Honors Theses

The cannabinoids are a class of molecules endogenous to the cannabis plant. Their scientific relevance has increased in recent years due to the mercurial legal status of marijuana across the United States. Some of the most known are cannabidiol (CBD), δ9-tetrahydrocannabinol (δ9-THC), and δ8-THC due in large part to their widespread use, especially in states where marijuana and related products are legal. However, cannabigerolic acid (CBGA) is arguably the most important cannabinoid; it is enzymatically converted into other acidic cannabinoids, which subsequently undergo non-enzymatic processes (isomerization, thermal decarboxylation, oxidation, etc.) to synthesize further cannabinoids. Although there is a wealth of …

Computational Investigations Into Astrochemical Inorganic Oxides, Ammonia Borane, And Genetic Algorithms, E. Michael Valencia

Honors Theses

The formulations of quantum mechanics in the early 1900s were exciting theoretical discoveries, but were not practical to apply until the advent of computers and the subsequent computational methods in 1951. With the introduction of tractable simplifications, procedures such as Hartree-Fock allowed for determination of properties of non-trivial systems. Presently, huge leads of computational power have allowed for extremely precise, quantitative work that can be applied to the human body, synthesis, or even astrochemical processes. This thesis presents works concerning 1) the history of quantum mechanics; 2) a brief primer on computational chemistry and its methods; 3) inorganic oxides in …

Dicyanobenzothiadiazole-Based Organic Dye As A Visible Light Absorbing Strong Photoinduced Oxidant With A 16 Microsecond Long-Lived Excited State, Ivy Li

Honors Theses

Strong photoinduced oxidants are important to organic synthesis and solar energy conversion to chemical fuels or electric. For these applications, visible light absorption is important to solar energy conversion and long-lived excited states are needed to drive catalysis. With respect to these desirable qualities, a series of five 5,6-dicyano[2,1,3]benzothiadiazole ((CN)₂BTD) dyes are examined as organic chromophores that can serve as strong photooxidants in catalytic systems. The series utilizes a ((CN)₂BTD) core with aryl groups on the periphery varying electron donation strengths relative to the core. The dyes are studied via both steady-state and transient absorption and …

Analysis Of The Light Responsive Azobenzene Peptide Nucleic Acid Duplexes, Kat Nguyen

Honors College Theses

Peptide nucleic acids (PNAs) are oligonucleotide analogues in which the sugar-phosphate backbone has been replaced by a pseudopeptide skeleton. Since PNAs use the natural nucleobases (Adenine, Thymine, Cytosine, Uracil, and Guanine) found in either DNA and/or RNA, they are able to hybridize according to Watson-Crick base-pairing to form duplexes. PNA is a promising therapeutic agent because they can function as antigene or antisense chemical agents. To further enhance their utility, we aim to incorporate a photoswitchable moiety using azobenzene. Here, we report the results of the synthesis and purification of a photoswitchable 11 mer PNA along with initial characterization efforts.

Computational And Spectroscopic Studies Of New Sulfur-Containing Dipole-Bound Anions, Nicholas Allen Kruse

Honors Theses

Sulfur and Nitrogen are essential ingredients in both life-supporting and light-harvesting molecules. Their presence also usually leads to the delocalization of electrons and large dipole and quadrupole moments. Such molecules are sometimes able to form negative ions through the electrostatic binding of an excess electron. These so-called multipole-bound (dipole-bound, quadrupole-bound, etc.) anions have been shown to be important in radiation damage in biology and electron transport processes. Here, we present our recent computational and experimental results studying the creation of new multipole-bound anions.

Stabilization Of Phenanthrene Anions In Helium Nanodroplets, Siegfried Kollotzek, Farhad Izadi, Miriam Meyer, Stefan Bergmeister, Fabio Zappa, Stephan Denifl, Olof E. Echt, Paul Scheier, Elisabeth Gruber

Faculty Publications

It has been debated for years if the polycyclic aromatic hydrocarbon phenanthrene exists in its anionic form, or, in other words, if its electron affinity (EA) is positive or negative. In this contribution we confirm that the bare phenanthrene anion Ph^- created in a binary collision with an electron at room temperature has a lifetime shorter than microseconds. However, the embedding of neutral phenanthrene molecules in negatively charged helium nanodroplets enables the formation of phenanthrene anions by charge transfer processes and the stabilization of the latter in the ultracold environment. Gentle shrinking of the helium matrix of phenanthrene-doped HNDs …

Aloso: Spectroscopy And Structure Of A New Group Of Astrochemical Molecules, Vincent J. Esposito, Tarek Trabelsi, Joseph S. Francisco

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

No abstract provided.

Real-Time Monitoring Of Paraquat Photodegradation Using Colloidal Gold Surface Enhanced Raman Spectroscopy, Nathan Wilson

Masters Theses & Specialist Projects

Monitoring chemical reactions in aqueous solution is a challenge because most instrumental techniques either are not suited for the rapid timescales, are not sensitive enough to detect products at low concentrations, or do not have sufficient structure-to-spectrum relationships. Raman spectroscopy is a promising method to monitor reactions, as it is fast, dependent on chemical structure, and has little interference from water. However, Raman scattering is generally very weak. Surface-enhanced Raman spectroscopy (SERS) improves the signal strength of Raman spectroscopy by using a metal surface plasmon, or oscillation of the surface’s electrons, to allow for highly selective and sensitive detection and …

Theoretical Studies Of Benzoquinone Reactivity In Acidic And Basic Environments, Natali Majoras

Honors Theses

Quinones are a class of organic compounds containing a six-membered unsaturated ring with two carbonyl groups. They are biologically relevant mostly due to their ability to participate in redox reactions. Prior experiments in our lab showed that quinones can induce protein modifications that are pH dependent. In an acidic environment the modifications were less significant than in a basic environment. Previous computational studies have also been carried out to model, in neutral solutions, the reaction between various quinones and various amines. Various amine groups are used as a model for the amino group of lysine to represent protein modification. The …