Materials Science and Engineering Commons^™

Electrochemical Nucleation Of Invar Alloy On Glassy Carbon Electrode, Xian-Jie Huang, Hui Yan, Shuai-Shuai Huang, Fang-Zu Yang, Zhong-Qun Tian, Shao-Min Zhou

Journal of Electrochemistry

The linear sweep voltammetry, cyclic voltammetry and potential step methods were used to study the electrodeposition mechanism of Invar nickel-iron alloy (the mass fraction of nickel was 32~36%) on glassy carbon electrode surface in the weak acidic bath. The results demonstrate that the electrodeposition is was a diffusion controlled irreversible electrode process in this system. The Scharifker-Hill (SH) theory theoritic model (SH) were was used employed to fitting the experimental data and the result shows that the codeposition of Invar alloy on glassy carbon electrode surface conformed to the diffusion controlled three-dimensional instantaneous nucleation mechanism. The kinetic parameters were obtained …

Electrochemical Synthesis Of Porous Polyaniline Electrodes Using Hkust-1 As A Template And Their Electrochemical Supercapacitor Property, Qiong Luan, Chun-Feng Xue, Hong-Ye Zhu, Fu-Juan Yang, Xu-Li Ma, Xiao-Gang Hao

Journal of Electrochemistry

Excellent electrode plays vital important role in the performance of supercapacitors. Polyaniline (PANI) with good conductivity is often used to prepare electrode. However, its available surface is limited and results in a poor supercapacitance in many cases. It is desirable to fabricate an electrode containing electroactive PANI with high surface area deriving from its porous structure. Here, the metal-organic framework (MOF) material with high surface area was selected as a hard template for synthesizing porous PANI. Microporous PANI composite electrodes (Micro-PANI/CC) were fabricated by depositing aniline on to carbon cloth (CC) pre-coated with MOF material of HKUST-1 using a unipolar …

Sn-Doped Α-Fe2O3 Photocatalyst Containing Oxygen Vacancy For Water-Splitting, Zu-Hua Wang, Dong-Fang Niu, Hui-Cheng Li, Rong-Bin Du, Heng Xu, Xin-Sheng Zhang

Journal of Electrochemistry

The α-Fe₂O₃ nanoparticles containing oxygen vacancies were synthesized in atmospheric N₂ by dip-dropping method without a high vacuum employed before annealing. The influences of annealing atmosphere and Sn-doping on the photocatalytic performance of α-Fe₂O₃ nanoparticles were studied by annealing the photocatalyst in N₂ or air and adding SnCl₄ to the precursor directly. The results showed that the current density of Sn-doping α-Fe₂O₃ annealed in N₂ at 550 °C and 1.23 V (vs. RHE) was 35 times greater than that of pristine α-Fe₂O₃ annealed in …

Preparation And Electrochemical Properties Of Attapulgite-Supported Nitrogen-Doped Carbon@Nico2O4 Composites For Supercapacitors, Hui Wan, Zong-Rong Ying, Xin-Dong Liu, Jian-Jian Lu, Wen-Wen Zhang

Journal of Electrochemistry

In this work, the attapulgite-supported nitrogen-doped carbon (ANC) was prepared by in-situ chemically polymerizing polyaniline coating upon attapulgite, followed by high temperature heat treatment, and then NiCo₂O₄was reacted onto the surface of ANC by a combination of hydrothermal reaction and calcination to synthesize ANC@NiCo₂O₄ composites. The chemical composition and morphology of the samples were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N₂ adsorption/desorption. The electrochemical properties were evaluated by means of constant current charge discharge (GCD) and cyclic voltammetry (CV). …

Preparations Of Mno2 Reference Electrodes For Corrosion Monitoring Of Reinforced Concrete, Li Yang, Bing Xu, Hai Wang, Ze-Hua Dong

Journal of Electrochemistry

In this work, the solid reference electrode was assemblied by using the electrochemically synthesized manganese dioxide (MnO₂) (EMD) powder, gel electrolyte and thin mortar layer for the durability evaluation of concrete. The EMD reference electrode exhibited higher potential stability (< 10 mV drift) than the chemically synthesied MnO₂ (CMD) based on half year potential tests in the saturated Ca(OH)₂ solution and hardened mortar. In addition, the EMD electrode was almost insensitive to the presences of chloride ion and corrosion inhibitor. Electrochemical impedance and polarization curves indicate that the EMD electrode had lower charge transfer resistance,higher exchange current density and lower temperature coefficient than the …

An Investigation In The Performance Of Lithium Sulfur Battery With A Tic Coated Separator, Jian-Hua Fang, Yong Cao, Mao-Ping Yang, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

To improve the specific capacity and cycle stability of lithium-sulfur (Li-S) battery, a TiC/Celgard coating separator was developed and its performance in Li-S battery was investigated. The electrochemical test results confirmed that the TiC coating layer could significantly increase the capacity and cycle stability. At a high rate of 2C, it still delivered the capacity of 650 mAh·g^-1. At 0.5C, the specific capacity was maintained at 841.3 mAh·g^-1 after 100 cycles.

Direct Electrochemistry Of Glucose Oxidase Based On Ws2 Quantum Dots And Its Biosensing Application, Chen-Lu Li, Hua-Ping Peng, Zhong-Nan Huang, Yi-Lun Sheng, Pei-Wen Wu, Xin-Hua Lin

Journal of Electrochemistry

In this study, a novel electrochemical glucose biosensor has been developed by immobilizing glucose oxidase (GOx) on tungsten disulfide quantum dots (WS₂ QDs) on the surface of glassy carbon electrode (GCE). Transmission electron microscopy, UV-vis spectroscopy and cyclic voltammetry were employed to characterize the morphology, structure, and electrochemical behaviors of the as-prepared WS₂ QDs and the biofilm modified electrode. The results suggested that the WS₂ QDs could accelerate the electron transfer between the electrode and the immobilized enzyme, which enabled the direct electrochemistry of GOx without any electron mediator. Besides, the immobilized GOx in WS₂ QDsfilm …

Application Of Adamantane Schiff Base Nickel Complexes/Graphene Oxide/Glassy Carbon Modified Electrode In Detection Of Carmine, Peng Guo, Zheng Liu, Hai-Ying Li, Li-Ming Ma

Journal of Electrochemistry

The Schiff base nickel complexes/graphene oxide/glassy carbon electrodes were prepared by embedded method and electrodeposition on which were used to quantitatively detect the contents of carmine. Cyclic voltammetry, chronoamperometry, scanning electron microscopy (SEM) and other methods were employed to characterize properties and morphologies of the modified electrodes. The results show that the adamantane double Schiff base nickel complexes/graphene oxide/glassy carbon electrode had high electric catalytic activity toward carmine oxidation reaction, and might provide an easy and quick way to detect carmine content with good reproducibility.

Single Molecule-Level Study Of Donor-Acceptor Interactions And Nanoscale Environment In Blends, Nicole Quist, Rebecca Grollman, Jeremy Rath, Alex Robertson, Michael Haley, John E. Anthony, Oksana Ostroverkhova

Chemistry Faculty Publications

Organic semiconductors have attracted considerable attention due to their applications in low-cost (opto)electronic devices. The most successful organic materials for applications that rely on charge carrier generation, such as solar cells, utilize blends of several types of molecules. In blends, the local environment strongly influences exciton and charge carrier dynamics. However, relationship between nanoscale features and photophysics is difficult to establish due to the lack of necessary spatial resolution. We use functionalized fluorinated pentacene (Pn) molecule as single molecule probes of intermolecular interactions and of the nanoscale environment in blends containing donor and acceptor molecules. Single Pn donor (D) molecules …

A Novel Composite Hydrogen Sensor Based On Pd Nanoclusters/Tio2 Nanotube Arrays, X. B. Wei, X. H. Yang, T. Wu, H. Y. Pang, G. D. Lv, S. H. Wu, S. B. Li, Zhi Chen

Electrical and Computer Engineering Faculty Publications

A novel composite hydrogen sensor, consisting of Pd nanoclusters/TiO₂ nanotube arrays, was fabricated and evaluated at room temperature. The Pd nanoclusters layer was deposited on top surface of the nanotube arrays by using a direct current (DC) magnetron sputtering method. Resistive response of the composite sensors to 0.5% hydrogen was measured. Experimental results indicated that the Pd nanoclusters can quickly and continually form or break multiple passages by absorbing or desorbing hydrogen, so that the composite hydrogen sensors have promising hydrogen sensitivity at room temperature.

Emergence Of Home Manufacturing In The Developed World: Return On Investment For Open-Source 3-D Printers., Emily E. Petersen, Joshua M. Pearce

Department of Materials Science and Engineering Publications

Through reduced 3-D printer cost, increased usability, and greater material selection, additive manufacturing has transitioned from business manufacturing to the average prosumer. This study serves as a representative model for the potential future of 3-D printing in the average American household by employing a printer operator who was relatively unfamiliar with 3-D printing and the 3-D design files of common items normally purchased by the average consumer. Twenty-six items were printed in thermoplastic and a cost analysis was performed through comparison to comparable, commercially available products at a low and high price range. When compared to the low-cost items, investment …

Collective Nonaffine Displacements In Amorphous Materials During Large-Amplitude Oscillatory Shear, Nikolai V. Priezjev

Mechanical and Materials Engineering Faculty Publications

Using molecular dynamics simulations, we study the transient response of a binary Lennard-Jones glass subjected to periodic shear deformation. The amorphous solid is modelled as the three-dimensional Kob-Andersen binary mixture at a low temperature. The cyclic loading is applied to slowly annealed, quiescent samples, which induces irreversible particle rearrangements at large strain amplitudes, leading to stress-strain hysteresis and a drift of the potential energy towards higher values. We find that the initial response to cyclic shear near the critical strain amplitude involves disconnected clusters of atoms with large nonaffine displacements. In contrast, the amplitude of shear stress oscillations decreases after …

Controlling Calcium Compound Formation In Biocompatible Materials For Tissue Regeneration And Repair In Mammals, Steven B. Jung, D. E. Day

Materials Science and Engineering Faculty Research & Creative Works

A biocompatible composition for tissue repair or regeneration in mammals comprising one or more glass former compounds selected from the group consisting of B₂O₃, P₂O₅, and SiO₂ and director elements selected from the group consisting of Cu, Sr, Zn, Fe, Mn, Cr, V, Nb, Mo, W, Ba, Co, S, Al, Ti, Y, Mg, Si and/or Ni to promote in vivo calcium compound formation of calcium carbonate or other calcium compounds other than hydroxyapatite. Upon direct application of the biocompatible composition to a mammalian host, calcium carbonate or other calcium compounds other …

Scaffold For Tissue Regeneration In Mammals, D. E. Day, Steven B. Jung, Roger F. Brown

Materials Science and Engineering Faculty Research & Creative Works

A three-dimensional scaffold with interconnected pores for repair of tissue comprising a scaffold body for structural support of the tissue scaffold, where the scaffold body comprises scaffold body components bonded to each other and made from component materials comprising about 40 to about 90 wt % B₂O₃, and two or more other oxides, wherein the scaffold body has a porosity between about 15 and about 90 vol %.

Dual Mechanism For Toughening And Sustained Aminoglycoside Elution From A Polyphosphate Hydrogel, Dwight D. Lane, Russell J. Stewart Phd

Biomedical Engineering Western Regional Conference

No abstract provided.

Redesign Of Computer Keyboards For Hospital And Consumer Use, Kent Williams, Brian Jensen, Anton Bowden

Biomedical Engineering Western Regional Conference

Application of carbon nanotube coatings to computer keyboards in order to reduce the spread of bacteria in hospitals and homes.

Keywords: carbon nanotube, bacteria, antimicrobial, keyboard, design, MRSA, biofilm

The Effect Of Biocomposite Material In A Composite Structure Under Compression Loading, Benjamin Andrew Sweeney

Master's Theses

While composite structures exhibit exceptional strength and weight saving possibilities for engineering applications, sometimes their overall cost and/or material performance can limit their usage when compared to conventional structural materials. Meanwhile ‘biocomposites’, composite structures consisting of natural fibers (i.e. bamboo fibers), display higher cost efficiency and unique structural benefits such as ‘sustainability’. This analysis will determine if the integration of these two different types of composites are beneficial to the overall structure. Specifically, the structure will consist of a one internal bamboo veneer biocomposite ply; and two external carbon fiber weave composite plies surrounding the bamboo biocomposite. To acquire results …

Reversible Control Of The Magnetization Of Fe₃O₄ Via Lithium Ions, Guodong Wei, Lin Wei, Dong Wang, Yufeng Tian, Yanxue Chen, Shishen Yan, Liangmo Mei, Jun Jiao

Mechanical and Materials Engineering Faculty Publications and Presentations

In this report, a reversible control of Fe₃O₄ saturated magnetization by Li ions is demonstrated. A miniature Li ion battery (LIB) was assembled using a Fe₃O₄ nanoparticle layer as the active cathode. A stable magnetism modulation is realized by a nondestructive electrochemical process in which the lithium insertion results in a valence change and partial redistribution of Fe cations in the crystal structure. The relation between the discharge voltage and the chemical phases were studied by ex situ X-ray diffraction and magnetic measurement. In a suitable discharge potential range, a reversible control of Fe₃O₄ saturated magnetization was obtained without structural …

Development Of Low Alloy Steel By Direct Metal Laser Sintering, Elias Jelis

Dissertations

The US Department of Defense is interested in developing, understanding, and optimizing process parameters for low alloy (4340/4140 steel) for the powder bed fusion process. Low alloy steel is used in parts where high strength and toughness are required. During parameter optimization, several aspects of the process are investigated. Powder size and morphology optimization is important for manufacturability because adequate packing is required to produce full density components. Microstructure evaluation is used in order to provide insight into parameters that lead to optimal mechanical performance and recoating performance. Influence of residual stress is evaluated with this process. Large thermal stress …

Heat Transfer In Silicon - Experiments And Simulation, Chihlin Huang

Theses

The purpose of this thesis is to study the heat transfer in silicon. Silicon is the key semiconductor material, and thermal processing is the traditional method that is used in semiconductor processing. In this research, we can predict the temperature of the silicon wafer during heating. This ability to predict wafer temperature during semiconductor processing will facilitate in the following: (a) Process temperature uniformity, (b) Film thickness uniformity, (c) Diffusion, (d) Process yield, (e) Thermally induced stresses, and (f) Device yield - spatially and temporally across the wafer. For low temperature applications, IC chips can be modeled to simulate the …