Physical Chemistry Commons^™

Electrochemical Fabrication Of The Ordered Polyaniline Nanowires Array, Yan-Xin Gao, Li-Chao Sun, Su-Yuan Xie, Kang Shi

Journal of Electrochemistry

The effects of electrochemical fabrication methods in different aniline concentrations on the morphologies of polyaniline, which was polymerized on the aligned-multi-walled carbon nanotubes electrode in H₂SO₄ or HClO₄ electrolyte solution, were investigated. It was demonstrated that the polyaniline nanowires would not be prepared by cyclic voltammotry, whereas the nanowires could be obtained by the potentiostatic method without forming the ordered array. Only when the aniline concentration in HClO₄ solution was high enough, the ordered polyaniline nanowires array could be fabricated by the constant current method.

Electrochemical Characterization Of (Phmgcl)2-Alcl3/Mixed Ether Electrolytes, Fei-Fei Wang, Yong-Sheng Guo, Jun Yang, Li-Yan-Na Nu, Jiu-Lin Wang

Journal of Electrochemistry

The (PhMgCl)₂-AlCl₃ salts were prepared and the electrochemical properties of (PhMgCl)₂-AlCl₃ electrolytes containing dimethoxyethane(DME)+THF, Diglyme(DG)+THF and Tetraglyme(TG)+THF solvents with different proportions on various metal electrodes were studied. Compared with (PhMgCl)₂-AlCl₃/THF, the (PhMgCl)₂-AlCl₃/DG+THF(3:2) solvents showed high ionic conductivity of 1.605×10^-3 S·cm^-1, good reversible Mg deposition behavior and anodic anti-oxidation performance with an electrochemical window wider than 2.8 V. In addition, the DG+THF mixed solvent could greatly lower the saturated vapor pressure by reducing from 23.46 kPa to 9.41 kPa, which suppresses volatilization of the …

Electrochemical Behavior Of Imidacloprid, Jie-Qiong Wang, Wang Zhang, Ming Chen, Guo-Wang Diao

Journal of Electrochemistry

The electrochemical behavior of imidacloprid（IDP）on glassy carbon electrode has been investigated by cyclic voltammetry. The result shows that the electrochemical reduction of IDP is irreversible and controlled by diffusion. At 25 ℃, the numbers of the electrons transferred of IDP in the electrochemical reaction are four. The diffusion coefficient of IDP is 2.44×10⁶ cm²·s^-1 and the diffusion activation energy is calculated to be 9.33 kJ·mol^-1.

Simultaneous Determinations Of Ascorbic Acid, Dopamine And Uric Acid At Ca/Gc Electrode, Ying Zhang, Wang Ren, Min-Jiao Li

Journal of Electrochemistry

The citric acid modified glassy carbon electrode (CA/GC) was constructed by potentiostatic technique and used for simultaneous determinations of ascorbic acid (AA), dopamine (DA) and uric acid (UA) by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The CA/GC electrode exhibits excellent electrocatalytic activity towards AA, DA and UA. The oxidation peaks are well separated with the potential differences between AA and DA, DA and UA, and AA and UA being 170, 130 and 300 mV, respectively, which is large enough to determine AA, DA and UA simultaneously. The catalytic peak currents obtained were linearly dependent on the concentrations of …

Cycle Lifetime Investigation Of Nickel Electrode Prepared By Electrochemical Impregnation For Applications In Aerospace Nickel Hydrogen Cells, Hai-Chang Zhang, Li-Xin Tan, Cheng Guo, Wen-Cheng Ming, Xue-Ying Ren

Journal of Electrochemistry

In this paper, the effects of overcharge, charge-discharge C rate and pore size on cycle lifetime of 4.5’ electrochemical impregnated nickel electrode were investigated. In the case of the electrode was overcharged to 170% of nominal capacity, the initial capacity of the electrode could be maintained 2.7 Ah up to 150 cycles without deterioration and a discharge capacity of 1.7 Ah (remaining 63% of 2.7 Ah) could be delivered after 300 cycles. Without overcharge, more than 300 charge-discharge cycles could be realized without loss of capacity and a discharge capacity of electrode could be maintained about 76% of initial capacity …

Ag Nanoparticles Self-Assembled Films On Iron Surface And Their Inhibition Properties, Zhe Zhang, Ming-Zi Jia, Le Ruan

Journal of Electrochemistry

The Ag nanoparticles were prepared in aqueous solutions through a chemical reduction method and transferred from water phase to toluene phase with the protection of 1-dodecanethiol (DDT). The polished iron electrode was immersed in the DDT-protected metal nanoparticles toluene solutions to form DDT/Ag nanoparticles self-assembled mixed films. Electrochemical methods such as electrochemical impedance spectroscopy and polarization curve measurement were used to study the inhibition properties of the self-assembled films in the 0.5 mol·L^-1 H₂SO₄ solution. The appearance of elements such as S and Ag from the XPS data identified the presences of DDT and Ag nanoparticles.

Function Assignment Within The Haloacid Dehalogenase Superfamily, Hua Huang

Chemistry and Chemical Biology ETDs

The HaloacidDehalogenase Enzyme Superfamily (HADSF) is a ubiquitous family of enzymes. Presently, more than 45,000 deposited gene sequences encode proteins of the HADSF, and only a fraction of these have defined structure and/or function. The work described in this thesis focuses on function determination in several members of the HADSF. An integrated bioinformatic-protein structure-enzyme mechanism approach was used to differentiate and track D-glycero-D-manno-heptose-1,7-bisphosphate phosphatase (GHMB) and histidinol phosphatephosphatase (HisB)orthologues; 2-keto-3-deoxynononic acid 9-phosphatephosphatase (KDN9PP) and 2-keto-3-deoxy-D-manno-octulosonic acid 8-phosphatephosphatase (KDO8PP)orthologues; inorganic pyrophosphatase and β-phosphoglucomutase(β-PGM) orthologues. In addition, a structure-function/bioinformatic analysis was carried-out on the bifunctional 1,3-diposphoglycerate acyltransferase/Cys-S-glyceryl-3-phosphate phosphatase (FKBH). Each study began …

Evolution Of Structure And Function Among Hotdog-Fold Thioesterases And Had Family Phosphatases, Wang Min

Chemistry and Chemical Biology ETDs

My doctoral research began with the function assignment to two domains of fusion protein BT4699, from Bacteriodes thetaiotaomicron, BF1314 from Bacteriodes fragilis and PG1653 from Porphyromonas gingivalis. BT4699, however, is insoluble, so its orthologue BF1314 and PG1653 were prepared and studied. The fusion proteins consist of a domain that belong to a large family of phosphatases known as Haloacid Dehalogenase (HAD) superfamily, and a domain belong to the hotdog-fold thioesterase superfamily. The genes encoding the fusion proteins located at an operon that encoding enzymes involved in the menaquinone biosynthetic pathway. So we assumed that the thioesterase domain is connected to …

Horizontally-Aligned Carbon Nanotubes Arrays And Their Interactions With Liquid Crystal Molecules: Physical Characteristics And Display Applications, Frederick Roussel, Jean-Francois Brun, Alexandre Allart, Limin Huang, Stephen O'Brien

Publications and Research

We report on the physical characteristics of horizonthally-grown Single-Walled Carbon Nanotubes (h-al-SWNT) arrays and their potential use as transparent and conducting alignment layer for liquid crystals display devices. Microscopy (SEM and AFM), spectroscopic (Raman) and electrical investigations demonstrate the strong anisotropy of h-al-SWNT arrays. Optical measurements show that h-al-SWNTs are efficient alignment layers for Liquid Crystal (LC) molecules allowing the fabrication of optical wave plates. Interactions between h-al-SWNT arrays and LC molecules are also investigated evidencing the weak azimuthal anchoring energy at the interface, which, in turn, leads to LC devices with a high pretilt angle. The electro-optical reponses of …

Applications Of Electronic Structure Theory To Problems In Strong-Field Chemistry, Inorganic Chemistry, And Nanomaterial Systems, Jason Anthony Sonk

Wayne State University Dissertations

This dissertation covers research performed on applications of electronic structure theory to various fields of chemistry and is divided into eight chapters. Chapters 2 through 4 describe a series of related works which explore applications of excited state electronic structure methods to problems in strong field chemistry. Chapters 5, 6, and 7 discuss the application of electronic structure theory methods to solving problems in inorganic chemistry. Finally, Chapter 8 looks at an application of electronic structure theory to nanomaterials.

Chapter 2 covers the modeling of electron dynamics of butadiene interacting with a short, intense laser pulse in the absence of …

State-Resolved Slice Imaging Of Photochemical Dynamics, Herath Mudiyans Nuradhika Herath

Wayne State University Dissertations

This dissertation focuses on the understanding the unimolecular photochemistry and dynamics

utilizing state-resolved slice imaging approach combined with the quantum-state selective

spectroscopy technique called resonance enhanced multi photon ionization (REMPI)

method. This powerful technique allows selecting the initial quantum states of the reactants

and determining the nal quantum states, energy, the orientation and alignments of

the products. In the investigations of photodissociation dynamics of acetone at 230 nm,

a bimodal distribution for the resulting CO photoproduct is identied. This observation

indicated the presence of unimolecular dissociation mechanism analogues to the roaming

dynamics reported in formaldehyde photodissociation. Moreover, another type of …

Water Diffusion In And Out Of The Β-Barrel Of Gfp And The Fast Maturing Fluorescent Protein, Turbogfp, Marc Zimmer, Binsen Li, Ramza Shahid, Paola Peshkepija

Chemistry Faculty Publications

The chromophore of fluorescent proteins is formed by an internal cyclization of the tripeptide 65SYG67 fragment and a subsequent oxidation. The oxidation is slow – the kinetics of this step is presumably improved in fast maturing GFPs. Water molecules can aid in the chromophore formation. We have used 50ns molecular dynamics simulations of the mature and immature forms of avGFP and TurboGFP to examine the diffusion of water molecules in-and-out of the protein β-barrel. Most crystal structures of GFPs have well-structured waters within hydrogen-bonding distance of Glu222 and Arg96. It has been proposed that they have an important role in …

Toward A Regional Radiocarbon Model For The East Texas Woodland Period, Robert Z. Selden Jr., Timothy K. Perttula

CRHR: Archaeology

The East Texas Radiocarbon Database contributes to an analysis of tempo and place for Woodland era (ca. 500 B.C. - A.D. 800) archaeological sites within the region. The temporal and spatial distributions of calibrated radiocarbon (¹⁴C) ages (n=127) with a standard deviation (ΔT) of 61 from archaeological sites with Woodland components (n=51) are useful in exploring the development and geographical continuity of the peoples in East Texas, and lead to a refinement of our current chronological understanding of the period. While the analysis of the dates produces less than significant findings due to sample size, they are used …

Modeling Regional Radicarbon Trends: A Case Study From The East Texas Woodland Period, Robert Z. Selden Jr.

CRHR: Archaeology

The East Texas Radiocarbon Database contributes to an analysis of tempo and place for Woodland era (~500 BC–AD 800) archaeological sites within the region. The temporal and spatial distributions of calibrated ¹⁴C ages (n = 127) with a standard deviation (ΔT) of 61 from archaeological sites with Woodland components (n = 51) are useful in exploring the development and geographical continuity of the peoples in east Texas, and lead to a refinement of our current chronological understanding of the period. While analysis of summed probability distributions (SPDs) produces less than significant findings due to sample size, they are used …

Dynamic Light Scattering And Microelectrophoresis: Main Prospects And Limitations, Vuk Uskoković

Pharmacy Faculty Articles and Research

Microelectrophoresis based on the dynamic light scattering (DLS) effect has been a major tool for assessing and controlling the conditions for stability of colloidal systems. However, both the DLS methods for characterization of the hydrodynamic size of dispersed submicron particles and the theory behind the electrokinetic phenomena are associated with fundamental and practical approximations that limit their sensitivity and information output. Some of these fundamental limitations, including the spherical approximation of DLS measurements and an inability of microelectrophoretic analyses of colloidal systems to detect discrete charges and differ between differently charged particle surfaces due to rotational diffusion and particle orientation …

Probing The Dynamics Of Radical Reactions With Polyatomic Hydrocarbons By Crossed-Beam Dc Slice Imaging, Armando Dura Estillore

Wayne State University Dissertations

This work presents results of crossed molecular beam imaging studies on the reaction of radicals (Cl and CN) with polyatomic hydrocarbons of different functionalities such as pentane isomers, deuterated alkanes, alkenes, and alcohols. The reactively scattered alkyl radicals are probed as a function of collision energy using single photon ionization. The scattering results for pentane are quite similar for all reactants, suggesting that the nature of the abstraction site has surprisingly little influence on the dynamics studied at ~5 and ~9 kcal/mol. The angular distributions are broad with a backscattered peak at low collision energy and a sharp forward peak …

Pegylated Silicon Nanowire Coated Silica Microparticles For Drug Delivery Across Intestinal Epithelium, Vuk Uskoković, Phin-Peng Lee, Laura Walsh, Kathleen Fischer, Tejal Dasai

Pharmacy Faculty Articles and Research

Composite particles made by growing nanoscopic silicon wires from the surface of monodispersed, microsized silica beads were tested in this study for their ability to affect the integrity and permeability of an epithelial cell layer. Polyethylene glycol (PEG) is known to sterically stabilize particles and prevent protein binding; as such, it is a routine way to impart in vivo longevity to drug carriers. The effect of the silica beads, both with and without silicon nanowires and PEG, on the disruption of the tight junctions in Caco-2 cells was evaluated by means of: (a) analysis of the localization of zonula occludens-1 …

Maxwell's Equations, Part V, David W. Ball

Chemistry Faculty Publications

This is the fifth installment in a series devoted to explaining Maxwell’s equations, the four mathematical statements upon which the classical theory of electromagnetic fields – and light – is based. Previous installments can be found on Spectroscopy’s website (whose URL can be found throughout these issues). Maxwell’s equations are expressed in the language of vector calculus, so a significant part of some previous columns have been devoted to explaining vector calculus, not spectroscopy. For better or worse, that’s par for the course, and it’s my job to explain it well – I trust readers will let me know if …

Ƴ-Selective Directed Catalytic Asymmetric Hydroboration Of 1,1-Disubstituted Alkenes, Sean M Smith, Gia L. Hoang, Rhitankar Pal, Mohammad O. Bani Khaled, Liberty S. W. Pelter, Xiao Cheng Zeng, James M. Takacs

Xiao Cheng Zeng Publications

Directed catalytic asymmetric hydroborations of 1,1-disubstituted alkenes afford ƴ

-dioxaborato amides and esters in high enantiomeric purity (90–95% ee).

On The Nature Of Weak Intermolecular Forces: A First Principles Approach To Hydrogen Bonding And Pi-Type Interactions, Kari Lorene Copeland

Electronic Theses and Dissertations

Computational quantum chemistry is a branch of chemistry that is based on quantum mechanics. In this field, chemical phenomena is represented in mathematical form and computers are used to provide numerical solutions to rigorous mathematical equations. Through this medium, the properties of atoms and molecules are calculated with high accuracy. Chapter 1 opens with a general discussion of science, the development of atomic theory and computational chemistry. Electronic structure theory is more extensively reviein Chapter 2. Hydrogen bonding and dispersion forces are defined in Chapter 3, and the procedures used to computationally study these type interactions are considered. Chapter 4 …