Materials Chemistry Commons^™

Preparations And Characters For Acetamiprid Of Molecular Imprinted Polymer Electrochemical Sensors, Bin Liu, Yong-Xing Huang, Hui-Ting Lian, Hong-Mei Wu

Journal of Electrochemistry

A novel molecularly imprinted membranes electrochemical sensor with good memory capacity to acetamiprid was developed. Based on electrodeposition technique, chitosan was deposited onto the surface of gold electrode as a functional polymer matrix along with aimed molecules acetamiprid and glutaraldehyde as a crosslinking agent. Cationic probe Ru(NH₃)₆Cl₃ was employed to indirectly investigate the electrochemical characteristics as well as the imprinted effect of the sensors. The results showed that the sensors had a specific recognition to acetamiprid compared to the structural similarity midacloprid and other pesticide. There is more sensitive response to acetamiprid at imprinted sensors …

Electrochemical Performance Of Tin Dioxide/Carbon Xerogel Composites As Anode Materials For Lithium-Ion Batteries, Xiao-Jing Liu, Lin-Lin Qin, Yi-Ning Shi, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

The tin dioxide/carbon xerogel composites were synthesized by using vacuum infiltration method. Structural characterization and morphology of the composites were investigated by using XRD, TEM and SEM techniques. BET test was performed to determine the pore size distributions of carbon xerogels and the composites. The results showed that the nano-sized SnO₂ particles (5~10 nm) were encapsulated in the pores of carbon xerogels. During the electrochemical tests the SnO₂ in the composites exhibited capacity retention of 61.9% after 100 cycles of charge-discharge tests at 100 mA/g.

Electrochemical Analysis Based On Molecular Recognition Of Nucleic Acids And Its Applications, Dian-Ming Zhou, Jian-Hui Jiang, Guo-Li Shen, Ru-Qin Yu

Journal of Electrochemistry

Nucleic acid as the carrier of genetic information and the functional molecules for molecular biology and bioanalytical chemistry has attracted increasing interest in electrochemical analysis. This review presents a brief outline of some electrochemical analytical assays based on molecular recognition of nucleic acids. Most of these methods are focused on the detection of nucleic acid sequence, genetic mutation and nucleic acids as functional molecules.

Study On The Fluorescent Carbon Nanodots With Electrochemical Methods, Bao-Ping Qi, Yan-Min Long, Lei Bao, Cui Liu, Zhi-Ling Zhang, Dai-Wen Pang

Journal of Electrochemistry

Carbon nanodots are a new class of fluorescent nanoparticles with a carbon-based core, which possess wavelength-tunable luminescence, high photostability, resistance to photobleaching, water-solubility, and ease of bioconjugation. Owing to their attractive merits, carbon nanodots like other carbon nanomaterials such as fullerene, carbon nanotubes and graphene, have attracted much attention. In addition, carbon nanodots can be inexpensively produced by electrochemical methods with simple post-processing under mild conditions. Electrochemical approaches have unique advantages in the analysis of surface structures and luminescence mechanism of materials. In this review, recent advances in electrochemical methods used for the synthesis and luminescence mechanism of fluorescent carbon …

Fabrication Of Ito Micro-Pore Electrochemical Sensor And The Detection Of Exocytosis, Hui Zhao, Ling Li, Pin-Gang He, Yu-Zhi Fang

Journal of Electrochemistry

Exocytosis is one of the major means for cells to transmit messages. Amperometric detection of exocytosis is an important method in studying communication between cells. In this study a new type of ITO micro-pore electrochemical sensor was fabricated by means of ITO and UV light lithographic mask and was used in the detection of exocytosis with promising results. Compared with the conventional method, the ITO micro-pore sensor can not only replace the carbon fiber electrode, but be combined with fluorescent or chemiluminescent methods in detecting the physiological phenomena of cells.

Study On The Electrochemical Behaviors Of Gc Electrode Modified With Carbon Nanotube-Polyelectrolytes And Its Application For Rutin Detection, Liang Hua, Xia-Qin Wu, Rong Wang

Journal of Electrochemistry

The electrochemical behaviors of rutin and ascorbic acid at single-wall carbon nanotube and polyelectrolytes (dimethyl-diallylammonium chloride, PDDA) film modified glassy carbon electrode was investigated. The cyclic voltammetric results showed that electron transfer of rutin at PDDA/SWCNTs/GC modified electrode is an adsorption-controlled process. The separation of oxidation peak potentials of rutin and ascorbic acid was more than 200 mV. The rutin concentration in the presence of AA were detected by differential pulse voltammetry (DPV). The experimental results indicated that the PDDA/SWCNTs/GC modified electrode can be used for the detection of rutin in the presence of high concentration of AA. The DPV …

Brief Introduction To Metal Corrosion And Protection, Hou-Yi Ma, Cong-Ying Cui, Ting Chen

Journal of Electrochemistry

This paper explains why corrosion processes are usually electrochemical in nature, describes the significance of electrochemical kinetic parameters of corrosion process, and briefly introduces the principles of corrosion protection, the most common corrosion protection methods and some special application of corrosion processes.

Effects Of Graphene On Electrochemical Behaviors Of Ni(Oh)2 As Supercapacitor Material, Zhen-Zhen Zhao, Wen-Bin Ni, Neng-Yue Gao, Hong-Bo Wang, Jian-Wei Zhao

Journal of Electrochemistry

The enhanced electrochemical properties of Ni(OH)₂ by the oxidation defected graphene were studied by both experimental method and theoretical calculation. The composite material of nano-Ni(OH)₂/graphene was prepared by potentiostatic deposition on the graphene substrate. Observed by TEM, the Ni(OH)₂ nanoparticles were well dispersed on the graphene substrate with the diameter of 5.0±0.5 nm. The capacitance of the system measured by the electrochemical test was 1928 F·g^-1. As indicated by the theoretical calculations, the composite material becomes conductive since Ni(OH)₂ is combined with surface functional groups of the graphene through the strong chemical interaction. …

Synthesis Of Limnpo4/C Used As Cathode Material For Lithium Ion Batteries, Xin Yang, Xue-Wu Liu, Gui-Chang Liu, Zhi-Cong Shi, Xin Li, Guo-Hua Chen

Journal of Electrochemistry

The LiMnPO₄/C composites were prepared using a solid-state reaction with addition of the resorcinol formaldehyde resin as the carbon source. The effects of reaction temperature and time on the crystal structure, morphology and electrochemical properties of the LiMnPO₄/C composites were investigated. The results show that the best performance was achieved with the LiMnPO₄/C composites synthesized at 600 ^oC for 12 h which had the particle sizes about 100~200 nm. The initial discharge capacities were 121.6 mAh·g^-1 at 0.02C, 110 mAh·g^-1 at 0.1C and more than 60 mAh·g^-1 at 1C. An …

Photogenerated Cathodic Protection Of Stainless Steel, Cheng-Gang Lin, Ze-Quan Lin, Jing Li, Chang-Jian Lin

Journal of Electrochemistry

A highly ordered Co-doped TiO₂ nanotube layers were fabricated by potentiostatic anodization of pure titanium in fluorinated electrolyte solutions followed by ion-exchange method. The structure and composition of the as-prepared Co-doped TiO₂ nanotube layers were characterized by SEM, XRD, UV-Vis, and XPS. The effects of dopant content on the morphologies, structural and photochemical properties of the TiO₂ nanotube arrays were investigated. The performances of photogenerated cathodic protection and the photoelectrochemical response for the Co-doped TiO₂ nanotube arrays under illumination and dark conditions were evaluated through the electrochemical measurements. The Co-doped TiO₂ nanotubes showed a stronger …

Synthesis And Electrochemical Behaviors Of Li2Coxmn1-XSio4 As A Cathode Material For Lithium-Ion Batteries, Lin Wang, Dong-Ping Lv, Yong Yang

Journal of Electrochemistry

We have successfully synthesized Li₂Co_xMn_1-xSiO₄/C (x=0, 0.1, 0.3, 0.5, 1)/C composites using hydrothermal assisted sol-gel process and ball-milling method. The results of X-ray diffraction show that the solid solutions of Li₂Co_xMn_1-xSiO₄ can be achieved when x≤0.3. The initial capacities increase from 70 mAh·g^-1 of Li₂MnSiO₄/C to 105 mAh·g^-1 of Li₂Co_0.3Mn_0.7SiO₄/C. Cyclic Voltammetry (CV) curves show that the replacement of Mn with Co can reduce the electrochemical polarization, making the insertion-extraction reaction …

Corrosion Characteristics Of Galvanized Flat Steel For Power Grounding In Nacl Solution Medium, Yong Li, Gao-Lin Wu, Bang-Fei Deng, Ping Yang, Xue-Ming Li, Qing-Bin Zong

Journal of Electrochemistry

The corrosion behavior of power grounding galvanized flat steel was studied by polarization measurement, electrochemical impedance spectroscopy and neutral salt spray test in 5% NaCl solutions. The surface morphologies of galvanized coating and structural properties of corrosion products were observed with scanning electron microscope and X-ray diffraction spectrometer, respectively. Results showed that under the temperatures of 20~60℃, the corrosion currents of galvanized flat steel increased with the temperature rising. The corrosion rate at 60℃ was 0.8408 mA·cm^-2, which is 2.9 times larger than that at 20℃. The corrosion rate dropped after reaching the maximal value of 1.95 mg·cm …

Electrelectrochemical Performances Of C-Coating And Co-Doping Lifepo4, Ying Bai, Jue-Ming Yang, Chun-Bo Qing, Wei-Feng Zhang

Journal of Electrochemistry

Phospho-olivine LiFePO₄ cathode materials were prepared by hydrothermal reaction at 200 ^oC. Sucrose was added as C-coating resource and Co was doped into the crystal lattice of LiFePO₄. In order to investigate the improvements in the electrochemical properties of Co-doped LiFePO₄, three samples, LiFePO₄, C-coated LiFePO₄ and C-coating-Co-doped LiFePO₄, were synthesized under the same preparation conditions. Charge/discharge studies reveal that the Co-doped LiFePO₄/C composite annealed at 400 ^oC exhibits marked improvement of specific capacity by diminishing the particle sizes and enhancement in the degree of crystallinity. …

Simultaneous Determination Of Dopamine(Da)And Epinephrine (Ep) At Ca/Gc Electrode, Wang Ren, Ying Zhang, Min-Jiao Li

Journal of Electrochemistry

The citric acid modified glassy carbon electrode (CA/GC) was prepared by potentiostatic technique and was used for detections of dopamine (DA), epinephrine (EP), and their mixtures by differential pulse voltammetry (DPV). The modified electrode shows the enhanced sensitivity and excellent electrochemical discrimination to DA and EP. The cathodic potential difference between DA and EP was about 380 mV, while no cathodic reduction of ascorbic acid (AA) was observed because the oxidation of AA is an irreversible reaction at the sensor. As a result, DA and EP could be determined simultaneously with the interferences of high concentrations of AA being eliminated. …

Vapor Liquid Solid Growths Of Germanium And Gallium Antimonide Nanowires, Ralph Alvarez, Esmeralda Arreola, Michael Oye, Meyya Meyyappan

STAR Program Research Presentations

Determining the optimal growth parameters for germanium (Ge) and gallium antimonide (GaSb) nanowires is the focus of this research. Given the fact that nano materials behave differently from their bulk counterparts we are researching some variables that influence nanowire diameter and length such as temperature, ramp rate, gas flow rate, and catalyst particle size. Based on the nano material size which is typically a few 10s of nanometers wide, these nano materials can be engineered to take advantage of their optical properties. Specifically the infrared (IR) response of Ge and GaSb nanowires are directly controllable based on their geometry. Fine …

Effects Of Ambient Gases On Icf Target Capsules, Bryan Chambers, Steve Letts, Michael Stadermann

STAR Program Research Presentations

We researched how the chemical and physical properties of a plasma polymer fuel capsule change as they are exposed to ambient gases. The fuel capsules contain the deuterium fuel inside them, they serve as the outer shell for the fuel and act as a ablator for the process. If they are reactive or diffusive with the atmosphere this can change their mass and effect the outcome of the fusion shots performed at the National Ignition Facility where High Powered Lasers are incident upon a gold hohlraum containing a capsule. We discovered that nitrogen and water vapor diffuse into the material …

Effect Of Au Content On Microstructural Evolution Of Snagcu Solder Joints That Undergo Isothermal Aging And Reliability Testing, Patrick J. Hyland

Master's Theses

Electronics, especially, printed circuit boards (PCBs) are a widespread technology. Metal coatings or “surface finishes” are often added to PCB board pads and component leads during manufacturing to improve their performance. Electroplated nickel/gold over copper is a popular surface finish for printed circuit boards and component leads. The presence of gold in solder joints, however, is known to have detrimental effects referred to as gold embrittlement. It is generally understood that tin-lead solder joints with less than 3 weight percent (wt%) of gold will not experience reliability issues. The acceptable level of gold in lead-free solder joints, however, is less …

Regiospecific Synthesis Of Ortho Substituted Phenols, Ravindra Kotha Balasainath

Masters Theses & Specialist Projects

Phenol is highly reactive toward electrophilic aromatic substitution. By this general approach, many groups can be appended to the ring, via halogenation, acylation, sulfonation, and other processes. Phenol contains the hydroxyl group (–OH), which is a strongly activating ortho/para directing group in aromatic electrophilic substitution (AES). AES gives a mixture of ortho-and para isomers, which must be separated.

The strong directing ability of phenol can also result in multiple substitutions on the aromatic ring which could be a major concern in the regiospecific synthesis of phenols. AES and Directed ortho--Metalation (DoM) are the only ways to directly substitute …

Single-Step Biofriendly Synthesis Of Surface Modifiable, Near-Spherical Gold Nanoparticles For Applications In Biological Detection And Catalysis, Vivek D. Badwaik

Masters Theses & Specialist Projects

There is an increased interest in understanding the toxicity and rational design of gold nanoparticles (GNPs) for biomedical applications in recent years. Such efforts warrant reliable, viable, and biofriendly synthetic methodology for GNPs with homogeneous sizes and shapes, particularly sizes above 30 nm, which is currently challenging. In the present study, an environmentally benign, biofriendly, singlestep/ single-phase synthetic method using dextrose as a reducing and capping agent in a buffered aqueous solution at moderate temperature is introduced. The resulting GNPs are near-spherical, stable, catalytically active, place exchangeable, and water-soluble within the size range of 10-120 nm. The added advantage of …

Fullerene-Based Organized Self-Assembled Photoactive Layer, Marcelo A. Yates ^, Danisha M. Rivera, Luis Echegoyen *

COURI Symposium Abstracts, Summer 2011

No abstract provided.

Endohedral Derivatives For Bulk Heterojunction Organic Photovoltaic Devices, Gustavo Hernandez^, Michael D. Irwin*

COURI Symposium Abstracts, Summer 2011

No abstract provided.

Electronic States In Layered Si/Sio2/Mos2 Nanostructures, Luis Edgardo Luciano^, Domingo Ferrer, Russell R. Chianelli, Manuel Ramos*

COURI Symposium Abstracts, Summer 2011

No abstract provided.

Application Of Raman Spectroscopy To Lubricants, Lubricated Surfaces And Lubrication Phenomena, David W. Johnson

Chemistry Faculty Publications

Recent advances in lasers and detector technologies and the development of low-cost instruments and fiber-optic probes have brought about an explosion in the lubrication systems being studied by Raman spectroscopy. This article provides examples of the use of Raman spectroscopy in the study of lubrication phenomena, including the characterization of liquid lubricants, lubricant additives, and solid lubricants; the study of vapor-phase lubrication; and the use of coated nanoparticles as lubricants.

Review Of Science For Science Librarians: Graphene, Kathleen A. Lehman

University Libraries Faculty Publications and Presentations

Graphene is, in many ways, a simple substance. Made of a single atomic layer of graphite, graphene has emerged as a material providing many surprises and having immense scientific and industrial potential. In 2010, scientists Andre K. Geim and Konstantin S. Novoselov received the Nobel Prize in Physics for their isolation of graphene and for their research pertaining to the ultrathin material. In his presentation speech, Professor Per Delsing described how we all have made graphene each time we write with a pencil: microscopic bits of graphite and graphene flake away as the pencil moves across the paper (Delsing 2010). …

The Preparation Of Functional Surfaces, Philip Thomas Dirlam

Master's Theses

Diels-Alder chemistry was utilized to manipulate the surface energy of glass substrates in reversible manner. Glass slides and capillaries were functionalized with hydrophobic dieneophiles resulting in a  non-wetting surface.  A retro Diels-Alder reaction facilitated by the thermal treatment of the surface’s function to cleave the hydrophobic dieneophile and resulted in the fabrication of a hydrophilic surface. Contact angle (CA) measurements were used as preliminary measurements for monitoring the changes in surface energy exhibited during the initial hydrophobic state (CA - 70±3°), after attachment of the dieneophile creating  a hydrophobic state (CA - 101±9°) followed by reestablishment of the hydrophilic state …

Development And Extrapolation Of An Undergraduate Laboratory Experiment To An Elastomeric Spinal Muscular Atrophy Brace, Richard Sterling Brose

Master's Theses

Ever since the advent of polymer science, polyurethanes have played a huge role in the industrial world. They have been used in endless applications from furniture padding to aircraft coatings, to binders for insensitive munitions. It is therefore important that the chemistry of polyurethanes is well understood as well as the ability to draw relationships between the raw materials selected and the end-use properties of the polymer. Because of the multitude of practical applications, the development of an undergraduate polymer chemistry laboratory focused on polyurethane elastomers is developed and described herein. Polymer chemistry students are exposed to hydroxyterminated polybutadiene (HTPB) …

Effect Of Pore Size On Pseudo-Capacitive Performance Of Nio In The Mixed Electrolyte Of Koh And Hexacyanoferrate, Wen Wu, Meng-Yan Hou, Dan-Dan Zhou, Yong-Yao Xia

Journal of Electrochemistry

In this paper, five kinds of NiO samples with different pore size distributions were synthesized .The electrochemical capacitance of the samples were characterized in 3 mol/L KOH solution with and without hexacyanoferrate addition. Electrochemical test results indicated the NiO sample with an optimum pore size of about 15 nm shows high Coulombic efficiency of the N₄(NiO) electrode as the redox reaction of hexacyanoferrate ions would be limited in the pore, thus prevent ion diffusion into the bulk electrolyte solution .

Investigation Of Supercapacitors Based On Polyvinyl Alcohol Hydrogel-Polymer Electrolyte, Kai-Qing Xu, Le-Qing Fan, Ji-Huai Wu, Qing Leng, Xin Zhong, Jian-Ming Lin, Miao-Liang Huang, Zhang Lan

Journal of Electrochemistry

For the first time, the supercapacitor based on the hydrogel-polymer electrolyte which consisted of the cross-linking of polyvinyl alcohol-glutaraldehyde (PVA-GA) using 2-acrylamido-2-methyl propane sulfonic acid (AMPS) as solicitation reagent was assembled. The gel polymer electrolyte was characterized by FTIR and AC impedance. The maximum ionic conductivity is 1.23 mS/cm at room temperature. The electrochemical properties of the supercapacitor were investigated by cyclic voltammetry, AC impedance spectra and constant current charge-discharge curve. The results show that the specific capacitance reachs 139 F/g with AMPS of 1.0 g and 0.05 mL of 5 %(by mass) GA. And the specific capacitance still retained …

Electric Vehicles And Power Batteries, Xin-Ping Ai, Han-Xi Yang

Journal of Electrochemistry

In retrospect of the historical development of Electric Vehicles (EV), the impact of battery technologies on the progress of EV was discussed. In consequence, it is concluded that the lack of advanced batteries was the main cause for the fluctuations of EV development and the sluggish commercialization of electric cars in the past century. After a brief introduction to the classification and the requirements of electric vehicles, the main issues of the batteries including safety, temperature range for operation and the cost as well as the effects of these factors on the applications of advanced batteries for electric vehicles were …

Preparation And Performance Of Carbon-Coated Si/C Composites, Li-Li Du, Quan-Chao Zhuang, Tao Wei, Yong-Li Cui, Zhi Sun, Shi-Gang Sun

Journal of Electrochemistry

Si/C composite for lithium ion batteries was obtained by pyrolyzing and ball-milling. The microstructure and component of the composite was characterized by SEM and XRD, the electrochemical performance was investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and galvano static charge-discharge tests. The results illustrate that the particle of Si/C composite prepared by pyrolysis exhibits inerratic morphology, uniform carbon-coating layer, good electrical conductivity, low resistance. The first intercalated-lithium capacity of the composite material is 4495 mAh/g; the first coulomb efficiency is 65.3%. From the second week the coulomb efficiency maintains 97%, and the capacity at the 100th cycle can …