Engineering Commons^™

Pulse Reverse Current Electrodeposited Tio2 Doped Ni-W Coating, Sydney Hughes

Williams Honors College, Honors Research Projects

Nickel-Tungsten (Ni-W) coatings via the pulse reverse current method have been under development as a potential replacement for typical Chromium/Cadmium coatings. To increase the effectiveness of Ni-W as a coating, dopants have been tested to decrease microcracks and pores and increase overall tribological performance. Previous research by Timken Engineered Surfaces Laboratory showed that Ni-W doped with TiO₂ nanoparticles had a positive effect on coating performance. The purpose of this study was to determine the ideal solution parameters (i.e. TiO₂ concentration, pH) to maximize the benefit of the dopant when samples are subjected to tribological testing. Here, solutions of …

Migration And Electropolymerization Of Methyl Methacrylate In Hardened Cement Paste Via Electrokinetic Treatment, Xi Xie

Doctoral Dissertations

Porous concrete structures are susceptible to the intrusion of chemical species, such as sulfates, chlorides, and carbon dioxide. Many technologies have been developed to repair or rehabilitate damaged concrete. These include cathodic protection, corrosion inhibitor addition, or the use of coatings and sealers. In recent years, a developing technology, electrokinetic nanoparticle treatment, has been shown to reduce concrete porosity, increase strength, promote corrosion resistance, and extend durability. This dissertation was conducted to explore a novel treatment to reduce the porosity of concrete via the application of electrokinetic transportation and electro-initiated polymerization of methyl methacrylate (MMA).

Potassium persulfate (PSP) was used …

Epitaxial Growth Of Semiconductors And Chiral Metal Surfaces Using Spin Coating And Electrodeposition, Meagan V. Kelso

Doctoral Dissertations

"The current primary methods for epitaxial growth are energy intensive, requiring high temperature or high vacuum to obtain quality thin films. This dissertation explores the solution process methods of electrodeposition and spin coating for growth of epitaxial thin films. First, a method is developed to directly electrodeposit epitaxial CH₃NH₃PbI₃ perovskite for solar cells on single crystal Au by electrochemically reducing I₂ in organic solution. Perovskite is a newly explored material for solar cells, and its efficiency may be further improved by increasing the crystalline order. Second, a study on epitaxially electrodeposited chiral metal surfaces …

Electrodeposited Semiconductor Nanostructures & Epitaxial Thin Films For Flexible Electronics, Naveen Kumar Mahenderkar

Doctoral Dissertations

"Single-crystal Si is the bedrock of semiconductor devices due to the high crystalline perfection which minimizes electron-hole recombination, and the dense native silicon oxide which minimizes surface states. To expand the palette of electronic materials beyond planar Si, an inexpensive source of highly ordered material is needed that can serve as an inert substrate for the epitaxial growth of grain boundary-free semiconductors, photonic materials, and superconductors. There is also a need for a simple, inexpensive, and scalable fabrication technique for the growth of semiconductor nanostructures and thin films. This dissertation focuses on the fabrication of semiconducting nanowires (polycrystalline Ge & …

Electrodeposited Epitaxial Cobalt Oxides And Copper Metal, Caleb M. Hull

Doctoral Dissertations

"Electrochemical deposition methods are presented for the deposition of Co(OH)₂ and Cu metal. Paper I shows the deposition of β-Co(OH)₂ on Ti through electrochemical reduction of [Co(en)₃]³⁺ to [Co(en)₃]²⁺ in 2M NaOH. The catalytic properties of the deposited Co(OH)₂ towards water oxidation is found comparable to Co₃O₄, with the surface of the Co(OH)₂ converting to CoOOH during the reaction. Paper II gives the conditions suitable for epitaxial growth of Co(OH)₂ on Au(100), Au(110), and Au(111) following the same reduction mechanism as described in Paper I. …

Novel Design And Synthesis Of Transition Metal Hydroxides And Oxides For Energy Storage Device Applications, Peifeng Li

Wayne State University Theses

Supercapacitors (SCs) and Li-ion batteries (LIBs) are two types of important electrical energy storage devices with high power density and high energy density respectively. However, to satisfy the increasing demand of high-performance energy storage devices, the energy density of SCs and power/energy densities of LIBs have to be further improved. The exploration, research, and development of electrode materials with high-performance for applications in SCs and LIBs are still needed to meet the ever-increasing demand on energy and power densities. Herein, the amorphous Ni-Co-Mo ternary hydroxides nanoflakes for SCs and oxides nanoflakes for LIBs with ultrathin stature, abundant open spaces, and …

Phase Field Modeling Of Electrodeposition Process In Lithium Metal Batteries, Nihal Acharya

Masters Theses

"One of the main weaknesses in long term performance of conventional lithium batteries is the growth of lithium microstructures on the electrode surface due to an electrochemical process, which can eventually lead to failure of these batteries. Suppressing this microstructure growth is a key in developing new generations of lithium metal batteries (LMBs). In this study, a two-dimensional (2D) phase field model is constructed to understand and determine the parameters controlling formation and evolution of microstructures in LMBs. A Ginzburg-Landau free energy functional, which is a function of concentration of Li⁺ and applied voltage, and a system consisting of …

Development And Demonstration Of Critical Components Of Aluminum Based Energy Storage Devices Using The Chloroaluminate Ionic Liquids, Mengqi Zhang

Doctoral Dissertations

This dissertation considers the development of porous carbon materials as the substrates for Al deposition/dissolution in an Al based ionic liquid flow battery (ILFB) and demonstration of an Al based hybrid supercapacitor. The Aluminum chloride/ 1-ethyl-3-methylimidazolium chloride chloroaluminate ionic liquid is utilized as the electrolyte for these Al based energy storage devices. The ILFB has less capital cost than the all-vanadium redox flow battery because of the inexpensive AlCl₃. The feasibility to equip a tank of solid aluminum chloride in an ILFB system aiming to improve energy density is investigated. A critical range of temperature data (50-130 celsius …

Electrodeposition Of Nanocrystalline Ni-Based Alloys, Hanseung Park

All Theses

Nanocrystalline materials can often process superior properties, but they are generally unstable against grain growth. Addition of a dopant can stabilize nanocrystalline alloys by decreasing the excess grain boundary energy as the thermodynamic driving force for grain growth and reducing grain boundary mobility via a kinetic effect of solute drag. In this thesis study, eight Ni-based alloys (Ni-W, Ni-P, Ni-Mo, Ni-Cu, Ni-B, Ni-Mg, Ni-Zn and Ni-Co) and pure Ni were made using an electrodeposition method. It is concluded that the use of different dopant can drastically affect the deposition mechanism as well as the morphology of resultant films. Ni-W and …

Development Of Palladium Nanowires, Chuanding Cheng

Doctoral Dissertations

Inherent limitations of traditional lithography have prompted the search for means of achieving self-assembly of nano-scale structures and networks for the next generation of electronic and photonic devices. The nanowire, the basic building block of a nanocircuit, has recently become the focus of intense research. Reports on nanowire synthesis and assembly have appeared in the scientific literature, which include Vapor-Liquid-Solid mechanism, template-based electrochemical fabrication, solvothermal or wet chemistry, and assembly by fluid alignment or microchannel networks. An ideal approach for practical application of nanowires would circumvent technical and economic constraints of templating. Here we report on the self-assembly of highly-ordered …

The Electrodeposition Of Iron-Manganese Alloys, Raymond D. Magorien

Bachelors Theses and Reports, 1928 - 1970

An electrodeposition of an iron-manganese alloy was made from the same conditions determined by previous re­search. Various addition agents were experimented with in an attempt to produce better conditions for electro-deposition. It was found advantageous to add small a­mounts of sodium lauryl sulfate and ammonium sulfite to the electrolyte.