Gas-Phase Ion/Ion Reactions Of Biomolecules: An Examination Of Carboxylate Reactivity And Arginine Based Non-Covalent Complexes,
2014
Purdue University
Gas-Phase Ion/Ion Reactions Of Biomolecules: An Examination Of Carboxylate Reactivity And Arginine Based Non-Covalent Complexes, Nathan Zachary Barefoot
Open Access Theses
The advent of Electrospray Ionization with the ability to generate multiply charges ions has contributed significantly to the study of gas-phase ion/ion reactions. With the tools available in mass spectrometry it has been shown that these reactions are effective at transforming one type of gaseous ion into another through a series of reactions. This work examines some of these reactions and their application to field of proteomics specifically focusing on the amino acids of arginine and lysine. NHS reagents have been shown to react to both of these molecules with in the gas-phase under different conditions but have relies on …
Characterization Of Water-Solid Interactions In Crystalline Ingredients And Development Of Deliquescence Measurement Recommendations,
2014
Purdue University
Characterization Of Water-Solid Interactions In Crystalline Ingredients And Development Of Deliquescence Measurement Recommendations, Matthew C. Allan
Open Access Theses
There are five major mechanisms of water-solid interactions. The primary focus of this thesis was on two of these: deliquescence and hydrate formation. Many crystalline food ingredients are deliquescent compounds (e.g., NaCl, sucrose, and ascorbic acid) and some are both deliquescent and hydrate formers (e.g., glucose, thiamine HCl, citric acid). Deliquescence is the first order phase transformation of a crystalline solid to a solution above a critical relative humidity (RH) known as the deliquescence point (RH0). A crystalline hydrate is a pseudo-polymorph in which water is incorporated into the crystal structure, altering the molecular formula and the physical properties.^ To …
A New Silver Electrode Based On The Composite Silver Sulfide/Attapulgite As Ionophore,
2014
Department of Chemistry and Material Science, Nanjing Forestry University, Nanjing 210037, China;
A New Silver Electrode Based On The Composite Silver Sulfide/Attapulgite As Ionophore, Wen-Zhuo Li, Ding-Jia Xu, Jun Wang, Jian-Long Wang
Journal of Electrochemistry
A novel silver ion selective electrode with its ionophore being a kind of organic/inorganic composite composed of silver sulfide and attapulgite has been prepared. Attapulgite is a type of natural inorganic polymer which has some properties similar to zeolite, such as a higher specific surface area and plenty of intercrystalline cavities. In this work, the silver ions were firstly adosrbed in the micropores of the attapulgite, then thioacetamidetiny was selected to mix with the prepared silver ions/ attapulgite composite. Owning to the existence of sulfur atoms in the structure of thioacetamide molecules, thioacetamide molecules can react with the silver ions/attapulgite …
Key Factors And Techno-Economic Analyses Of Manganese Electrolysis Process,
2014
Chinese Research Academy of Environment Sciences, Beijing 100012, China;
Key Factors And Techno-Economic Analyses Of Manganese Electrolysis Process, Gui-Mei Han, Fu-Yuan Xu, Lin-Hua Jiang, Zhi-Gang Dan, Xiao-Juan Gao, Ning Duan
Journal of Electrochemistry
This paper first studied the key factors affecting the initial manganese electrolysis process, including concentration of Mn2+, electrolysis time, overpotential, and then optimized these processing parameters with the chronocoulometry method under a three-electrode system. The results showed that, during the initial manganese electrolysis process, hydrogen evolution occurred more significantly on the stainless steel surface. As electrolysis process continued, manganese covered the stainless steel surface gradually, and hydrogen evolution reaction restrained which all contributed to the higher current efficiency. Besides, the limiting current density appeared at high overpotential region, and the reaction was controlled by diffusion process. In 0.02 …
Surface Enhanced Raman Spectroscopic Studies Of Pyridine Adsorbed On Ti/Au@Sio2 Film Electrode,
2014
Soochow University
Surface Enhanced Raman Spectroscopic Studies Of Pyridine Adsorbed On Ti/Au@Sio2 Film Electrode, Min-Min Xu, Ke Liu, Qing-Hua Guo, Jian-Lin Yao
Journal of Electrochemistry
This study was performed based on shell-isolated nanoparticles-enhanced Raman spectroscopy (SHINERS) technology. The Au@SiO2 nanoparticles were prepared and characterized by TEM and cyclic voltammetry. It was shown that the shell of SiO2 was compact. The high quality signal measured by surface enhanced Raman spectroscopy (SERS) was obtained from the adsorbed pyridine on Ti/Au@SiO2 electrode. The origin of the SERS signals was further confirmed by testing Pt and Ni electrodes. In addition, potential dependent adsorption behavior was investigated. It was found that pyridine was adsorbed parallel on the surface from -0.1 V to -0.6 V, and converted to …
Horseradish Peroxidase-Attapulgite Clay Nanocomposites: Fabrication And Application To Sensing The Extracellular H2O2 Released From Cells,
2014
Jiangsu Key Laboratory of New Power Batteries, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210046, China;
Horseradish Peroxidase-Attapulgite Clay Nanocomposites: Fabrication And Application To Sensing The Extracellular H2O2 Released From Cells, Ping Wu, Chen-Xin Cai
Journal of Electrochemistry
The nanostructured attapulgite clay was employed as a support matrix for immobilizing horseradish peroxidase (HRP). FTIR and electrochemical methods demonstrated that HRP had been effectively assembled on attapulgite surface with the formation of HRP-attapulgite nanocomposites. The HRP-attapulgite hybrid was deposited on the glassy carbon (GC) electrode forming the HRP-attapulgite/GC electrode. Cyclic voltammetric results showed a pair of well-defined redox peaks, which were ascribed to direct electron transfer (DET) of HRP, with the formal potential E0′ = -335 mV (vs. SCE) in the phosphate buffer solution (PBS, pH 7.0). The dependence of E0′ on solution pH indicated …
Novel Electrochemical Interfaces Based On Functional Nanomaterials And Their Related Applications,
2014
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022;University of Chinese Academy of Sciences, Beijing 100039;
Novel Electrochemical Interfaces Based On Functional Nanomaterials And Their Related Applications, Cheng-Zhou Zhu, Lei Han, Shao-Jun Dong
Journal of Electrochemistry
Due to the unique optical, electronic, magnetic and catalytic properties, functional nanomaterials provide new opportunities for the rapid development in a variety of disciplines and show considerable promise in different fields. Specifically, constructions of the novel electrochemical interface using various nanomaterials and exploring their advanced electrochemical properties have received great attention to develop electrochemical devices with potential applications. In this account, we focus on our up-to-date progress in the construction of novel electrochemical interfaces based on nanomaterials, mainly highlighting our research advances on electrochemical sensors, fuel cells and fluorescence spectroelectrochemistry. These novel advanced nanomaterials endow them excellent performances and open …
Preparation And Photocatalytic Properties Of Zno Nanorod Arrays On Ti Substrates,
2014
College of Chemistry and Chemical Eegineering, Taiyuan University of Technology, Taiyuan 030024, China;
Preparation And Photocatalytic Properties Of Zno Nanorod Arrays On Ti Substrates, Jia-Ming Yang, Ling-Jun Han, Li-Ping Zhong, Zhen-Hai Liang
Journal of Electrochemistry
In this paper, the uniform ZnO nanorod arrays were prepared by galvanostatic electrodeposition on Ti Substrates. The morphology and structure of samples were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effects of the concentration of Zn(NO3)2 and the deposition current on the morphology of the ZnO nanorod arrays were investigated. Photocatalytic properties of ZnO nanorod arrays were investigated by degradation of methyl orange (MO) under UV-light irradiation. The analysis revealed that the concentration of Zn(NO3)2 and the deposition current strongly influenced the morphology of the ZnO nanorod arrays. Compared with …
The Ionic Diffusion Model For The Solid Oxide Cathode And Its Verification By The Electrolysis Of Ta2O5 In Molten Cacl2,
2014
College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China;
The Ionic Diffusion Model For The Solid Oxide Cathode And Its Verification By The Electrolysis Of Ta2O5 In Molten Cacl2, Hua-Lin Chen, Zhi-Yong Wang, Xian-Bo Jin, George Z. Chen
Journal of Electrochemistry
The deoxidation speed of a solid oxide cathode in molten CaCl2 can be estimated by the PRS steady diffusion model of O2-, which correlates the deoxidation speed with the precursor porosity, P, the metal-to-oxide molar volume ratio, R, and the cathode volume shrinkage S. The PRS model indicates that the porosity of the oxide cathode has important influence on the deoxidation speed, and provides a very simple equation for the prediction of the optimal cathode porosity. For the electrolysis of Ta2O5, the porosity of the cathode is better to be within 50%. …
Effects Of Conformational Transformations On Electronic Transport Properties Of Optical Molecular Switches: An Ab Initio Study,
2014
State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210008, China;
Effects Of Conformational Transformations On Electronic Transport Properties Of Optical Molecular Switches: An Ab Initio Study, Yuan-Yuan He, Jian-Wei Zhao
Journal of Electrochemistry
A series of model molecules with 4 kinds of conformational transformations have been investigated as optical molecular switches by using density functional theory combined with nonequilibrium Green’s function method. The theoretical calculations show that molecules after conformational transformations have photoswitching characteristics. We find that the photochromic molecules with the same conformational transformation usually have a similar current on/off state when they are applied as photoshwitches. Among these transformations, the molecular switch with E(“trans”)/Z(“cis”)-isomerisation of the NN double bond has the highest current on-off ratio. The influences of the energy gap (HLG) between the highest occupied molecular orbital (HOMO) and the …
Microfabrication And Redox Properties Of The Single Microcrystal Of Na3Co(Cn)6/Nacl Solid Solution,
2014
State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;
Microfabrication And Redox Properties Of The Single Microcrystal Of Na3Co(Cn)6/Nacl Solid Solution, Yi-Liang Zhu, De-Zhi Yang, Ya-Qiong Su, De-Yin Wu, Zhong-Qun Tian, Dong-Ping Zhan
Journal of Electrochemistry
Although the molecular structures are similar to each other, the redox property of Co(CN)63- at solid/liquid interface is not so good as Fe(CN)63-. In this paper, scanning electrochemical microscopy (SECM) was adopted to construct an electrochemical microsystem with a volume of fL~pL, in which a micropipette with micrometer-sized orifice was employed as the scanning tip. Due to the evaporation of water, the NaCl electrolyte is concentrated to form a microcrystal. During the crystallization, the redox species Co(CN)63- replaced the sites of NaCl65- unit due to their matching lattice parameters, i.e., the …
23Na Mas Nmr Spectroscopic Study Of Na2Mnpo4F As Cathode Material For Sodium-Ion Battery,
2014
State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;
23Na Mas Nmr Spectroscopic Study Of Na2Mnpo4F As Cathode Material For Sodium-Ion Battery, Xu Hou, Gui-Ming Zhong, Xiao-Chen Lin, Zi-Geng Liu, Xiao-Biao Wu, Yong Yang
Journal of Electrochemistry
The Na2MnPO4F is one of the promising cathode materials for the sodium ion batteries. In the paper, we employed the ex situ X-ray diffraction and solid state NMR techniques to study the charge and discharge processes of this material, including the crystal structure and sodium sites changes. The ex situ x-ray diffraction patterns showed that two new diffraction peaks could be observed at 31o and 36o indicating an intermediate phase formed with the extraction of Na+. From the 23Na MAS NMR spectrum of the material, three peaks were seen at -209 …
Effects Of Oxygen Coverage And Hydrated Proton Model On The Dft Calculation Of Oxygen Reduction Pathways On The Pt(111) Surface,
2014
College of Chemistry and Chemical Engineering, Hunan University of Arts and Science, Changde 415000, Hunan, China;College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China;
Effects Of Oxygen Coverage And Hydrated Proton Model On The Dft Calculation Of Oxygen Reduction Pathways On The Pt(111) Surface, Li-Hui Ou, Sheng-Li Chen
Journal of Electrochemistry
DFT calculation is used to study various possible steps in the oxygen reduction reaction (ORR), including the adsorption and dissociation process of O2 and the serial protonation process of dissociated products to form H2O on the Pt(111) surface. By using slabs of different sizes, and different numbers of pre-adsorbed oxygen atoms, the coverage effects on the pathways are investigated. The calculated results using different hydrated proton models are also compared. It is shown that the initial step of the ORR is the formation of a protonated end-on chemisorbed state of OOH*, which can transform to an unprotonated …
Electrochemistry At Liquid/Liquid Interfaces And Its Recent Progresses,
2014
Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China;
Electrochemistry At Liquid/Liquid Interfaces And Its Recent Progresses, Jing Gu, Yong-Hui Qiao, Xin-Yu Zhu, Xiao-Hong Yin, Xin Zhang, Ye Chen, Zhi-Wei Zhu, Yuan-Hua Shao
Journal of Electrochemistry
Electrochemistry and electroanalytical chemistry at a liquid/liquid interface have attracted much attention in the past few decades since they have been closely related to many applications including exploration in mechanisms of extraction processes and chemical sensing, as well as investigations in phase transfer catalysis, drug release and mimicking the function of biological membranes. In this review, recent progresses in this field in the last decade, especially the investigations in microstructure of liquid/liquid interface, charge (ion and electron) transfer reactions and functionalization of liquid/liquid interfaces, are reviewed.
Nitroxide Radicals For Low Frequency Electron Paramagnetic Resonance Imaging (Epri),
2014
University of Denver
Nitroxide Radicals For Low Frequency Electron Paramagnetic Resonance Imaging (Epri), Joshua R. Biller
Electronic Theses and Dissertations
Optimization of nitroxides as probes for EPR imaging requires detailed understanding of spectral properties such as spin lattice relaxation times, spin packet linewidths, and nuclear hyperfine splitting. Initial measurements of relaxation times for six low molecular weight nitroxides at X-band stimulated further measurement at frequencies between 250 MHz and 34 GHz. The impact of tumbling was studied with perdeuterated 2,2,6,6-tetramethyl-4-piperidinyl-1-oxyl (PDT) in five solvents with viscosities resulting in tumbling correlation times, τR, between 4 and 50 ps. A set of three 14N/15N pairs of nitroxides in water was selected such that τR varied between …
Ab-Initio Study Of H2 Adsorption Upon The 001, 110, And 100 Surface Of Magnesium,
2014
University of Arkansas Little Rock
Ab-Initio Study Of H2 Adsorption Upon The 001, 110, And 100 Surface Of Magnesium, Thomas F. Armstrong
Theses and Dissertations
Until recently, the only pathway for H2 adsorption onto conventional magnesium thin films was the [001] surface. With the discovery of Mg nanoblade/nanotree fabrication, there are now multiple surfaces for adsorption. A keen understanding of each surface's hydrogen adsorption kinetics is a key part of deciding if these surfaces present a more attractive hydrogen storage material than conventional thin films. This study focused on the use of ab-initio methods to compare the adsorption of H2 molecules onto the [001], [100], and [110] surfaces as well as an analysis of hybrid functionals and their advantages over traditional functionals for minimum energy …
Organic-Inorganic Hybrid Nanostructures For Solar Cell Applications,
2014
University of Arkansas Little Rock
Organic-Inorganic Hybrid Nanostructures For Solar Cell Applications, Samir Mahdi Abdulalmohsin
Theses and Dissertations
The enticing electro-optical properties of nanostructured materials such as carbon nanotubes, graphene, CdS nanocrystals and ZnO nanowrie bring new vigor into the innovation of photovoltaics. The main purpose of this dissertation is to develop novel nano-structured materials for low cost solar cell applications. Fabrication, characterization, and solar cell application of organic-inorganic hybrid structures are the main focus of this research. Polyaniline (PANI)/multi-walled carbon nanotube (MWNT) composite films were synthesized by an electrochemical polymerization of aniline with airbrushed MWNTs on ITO substrates. It was found that the incorporation of MWNTs in PANI effectively increase the film conductivity with a percolation threshold …
X-Ray Structure Analysis And Topological Charge Density Studies Of Gossypol Derivatives,
2014
LSU New Orleans
X-Ray Structure Analysis And Topological Charge Density Studies Of Gossypol Derivatives, Carlos Zelaya
LSU New Orleans Theses and Dissertations
Gossypol and gossypol derivatives are natural byproducts of a variety of cotton plant species that poses interesting chemical, biological, and medicinal properties that are currently heavily researched. Supporting evidence suggest that gossypol and gossypol derivatives act on the Bcl-2 proteins that have been linked to certain cancers. Gossypol amine derivatives, specifically, are actively researched and a variety of amine derivatives have already been synthesized. However, gossypol and its derivatives are challenging compounds to work with because many of its derivatives tend to exist in various tautomeric forms. When analyzing gossypol and its derivatives it is the complex electron configuration that …
Co2 Reduction Under Periodic Illumination Of Zns,
2014
University of Kentucky
Co2 Reduction Under Periodic Illumination Of Zns, Ruixin Zhou, Marcelo I. Guzman
Chemistry Faculty Publications
The photoreduction of CO2 to formate (HCOO–) in sphalerite (ZnS) aqueous suspensions is systematically studied in the presence of Na2S hole scavenger. A series of cut-on filters at λcut-on ≥ 280, 295, 305, 320, and 400 nm are used to measure the reaction rate of formate production. The dependence of the measured reaction rates on λcut-on indicates that a wavelength of λ = 345 nm is associated with the actual bandgap of the semiconductor nanocrystallites suspended in water. The results from apparent quantum yield measurements during periodic illumination experiments suggest that (1) valence-band …
Electrically Controlled Formation And Release Of Admicelles For Solid Phase Extraction,
2014
Western Kentucky University
Electrically Controlled Formation And Release Of Admicelles For Solid Phase Extraction, Sukyeon Lee
Masters Theses & Specialist Projects
Solid phase extraction is one of the most widely used methods to concentrate diluted compounds in a solution. Substances can be extracted into admicelles and hemimicelles, which are surface adsorbed micelles and surfactant monolayers, respectively. Investigations of the electrical control of surfactants on surfaces for the purpose of analyte preconcentration prior to chromatographic analysis are presented. The surfactant layer serves as the “stationary phase” in a solid phase extraction sorbent scenario. Analytes are adsorbed on this layer, and then released from the solid phase via surfactant removal. The attachment and removal of the surfactant are controlled by means of an …
