Engineering Commons^™

Functional Bottlebrush Polymer Additives For Thin Films And Coatings, Travis S. Laws

Doctoral Dissertations

Bottlebrush polymers are a class of highly branched polymers consisting of polymeric side chains that are densely grafted to a linear backbone. Their highly branched architecture results in surface enrichment across a broad range of materials. The goal of my research has been centered around the design of functional bottlebrush polymers and their use as surface active additives in blend films and coatings.

In the first chapter, we examine the segregation behavior of polystyrene bottlebrushes that are blended with linear polystyrene. We systematically vary the lengths of the bottlebrush backbone (Nb), side-chain (Nsc), and the linear matrix (Nm) in order …

An Approach For Material Model Identification Of A Composite Coating Using Micro-Indentation And Multi-Scale Simulations, Pouya Shojaei, Riccardo Scazzosi, Mohamed Trabia, Brendan O’Toole, Marco Giglio, Xing Zhang, Yiliang Liao, Andrea Manes

Mechanical Engineering Faculty Research

While deposited thin film coatings can help enhance surface characteristics such as hardness and friction, their effective incorporation in product design is restricted by the limited understand-ing of their mechanical behavior. To address this, an approach combining micro-indentation and meso/micro-scale simulations was proposed. In this approach, micro-indentation testing was conducted on both the coating and the substrate. A meso-scale uniaxial compression finite element model was developed to obtain a material model of the coating. This material model was incorporated within an axisymmetric micro-scale model of the coating to simulate the indentation. The proposed approach was applied to a Ti/SiC metal …

The Influence Of Pulse-Plasma Treatment On The Phase Composition And Hardness Of Fe-Tib2-Crb2 Coatings, A. B. Kengesbekov, B. K. Rakhadilov, Yu. N. Tyurin, N. M. Magazov, M. K. Kylyshkanov, Zh. B. Sagdoldina

Eurasian Journal of Physics and Functional Materials

This work are presented the research results of pulse plasma treatment influence on the phase composition, hardness, roughness and element composition of coatings on the bases of Fe-TiB2-CrB2. The Fe-TiB2-CrB2 coatingwas depositedby detonation method. The following pulse-plasmatreatment was used to modify the structure and properties of the surface layers of the sprayed coating. The results of mechanical experiments showed that the hardness of Fe-TiB2-CrB2 coating increased after the treatment. On the basis of the X-ray analysis, it has been established that the increase of coating hardness is connected with phase transformations in a surface layer, in particular, with formation of …

Effect Of The Detonation Spraying Mode On The Tribological Properties Of Nicr-Al2o3 Coatings, B. K. Rakhadilov, D. B. Buitkenov, E. Kabdykenova, Zh. B. Sagdoldina, L. G. Zhurerova

Eurasian Journal of Physics and Functional Materials

The article presents the study results of detonation spraying parameters on the phase composition and tribological properties of NiCr-Al 2 O 3 powder coatings. The spraying was carried out at a ratio of the acetylene oxygen mixture O 2 /C 2 H2 =1.856. The detonation barrel filling volume with an explosive gas mixture varied from 30% to 68%. It is determined that the phase composition of the NiCr-Al 2 O 3 coatings varies depending on the degree of detonation barrel filling. With an increase in the detonation barrels filling volume, the intensity of the NiCr diffraction peaks is decreased, and …

Influence Of Pulsed Plasma Treatment On Phase Composition And Hardness Of Cr3c2-Nicr Coatings, D. N. Kakimzhanov, B. K. Rakhadilov, Yu. N. Tyurin, O. V. Kolisnichenko, L. G. Zhurerova, M. K. Dautbekov

Eurasian Journal of Physics and Functional Materials

In this study, the research results of the influence of pulsed plasma treatment on phase composition, hardness, and roughness of Cr 3 C 2 -NiCr coatings are presented. The Cr 3 C2 -NiCr coating was applied to substrate 12Kh18N10T stainless steel by detonation spraying method. To change the physical and mechanical properties of sprayed coating's surface layers, subsequent pulse plasma treatment was used. The pulse plasma treatment leads to changing the roughness of Cr 3 C2 -NiCr coating. The results of mechanical tests showed that after pulsed plasma treatment, the hardness of Cr 3 C 2 -NiCr coating is increased. …

Changes In The Structure And Properties Of Zro2 Detonation Coatings During Annealing, B. K. Rakhadilov, D. N. Kakimzhanov, G. Botabaeva, D. B. Buitkenov, N. Kantai, L. B. Bayatanova

Eurasian Journal of Physics and Functional Materials

The article studied the effect of annealing on the structure and properties of zirconium dioxide coatings obtained by detonation spraying. Detonation spraying was realized on a computerized detonation spray ing complex of the new generation CCDS2000. Determined that coatings made of zirconium dioxide are characterized by high adhesive strength of adherence to the substrate. Thermal annealing of coated samples was performed at temperatures of 900-1200^◦C. It was determined that the microhardness of zir conium dioxide coatings increases by 10-25% depending on the annealing temperature after annealing. The results of nanoindentation showed that the nanohardness of the coatings after …

Obtained Of Powder Coatings By Detonation Spraying, D. B. Buitkenov, B. K. Rakhadilov, Zh. B. Sagdoldina, M. Maulet

Eurasian Journal of Physics and Functional Materials

In this work, consider the aspects of obtaining powder coatings that possessing certain working properties obtained by detonation spraying. Experimental research were carried on the effect of technological parameters of the detonation spraying process on the phase composition and properties of Ti-Si-C coatings. It is determined that when the volume of filling the detonation barrel with an explosive mixture increases to 70% in the detonation wave flow, the Ti₃SiC₂ powder partially decomposes into TiC consequently the high-speed shock interaction of heated to high temperatures. Installed that when filling the barrel with an explosive mixture of 50% and …

The Effect Of Detonation Spraying On The Phase Composition And Hardness Of Al2o3 Coatings, B. K. Rakhadilov, D. B. Buytkenov, D. Kakimzhanov, R. S. Kozhanova, G. S. Bektasova

Eurasian Journal of Physics and Functional Materials

The article were studied the e ect of detonation spraying on the structure and properties of Al 2 O 3 coatings. It was determined that reducing the delay time between shots is leading to increase the hardness and elastic module of Al 2 O 3 coatings. It was found on the basis of X-ray di raction analysis that the main reason for the increasing in hardness with a decreasing in the delay time between shots is associated with increasing in the volume fraction of α -Al 2 O 3 phase. The studies of X-ray di raction presented that the highest …

Enhanced Electrochemical Performance Of Li-Ion Battery Cathodes By Atomic Layer Deposition, Yan Gao

Doctoral Dissertations

”Li-ion battery now plays an irreplaceable role in supplying green and convenient energy. In this work, atomic layer deposition (ALD) was used to modify Li-ion battery cathode particles for performance enhancement.

An ultrathin and conductive CeO₂ ALD film was deposited on Li-rich layered cathode particles, of which the specific capacity and cyclic stability were significantly improved. On the same cathode particles, FeO_x ALD and post-annealing resulted in a stable and conductive surface spinel phase to improve the performance.

Synergetic TiN coating and Ti doping were performed on a LiFePO₄ (LFP) cathode and extended its cycle life. The …

Antibacterial Properties Of Mussel-Inspired Polydopamine Coatings Prepared By A Simple Two-Step Shaking-Assisted Method, Pegah Kord Fooroshani, Elizabeth Polega, Kevin Thomson, Mohammad Saleh Akram Bhuiyan, Rattapol Pinnaratip, Mikhail Trought, Chito E. Kendrick, Yuesheng Gao, Kahryn Perrine, Lei Pan, Bruce P. Lee

Michigan Tech Publications

A simple two-step, shaking-assisted polydopamine (PDA) coating technique was used to impart polypropylene (PP) mesh with antimicrobial properties. In this modified method, a relatively large concentration of dopamine (20 mg ml⁻¹) was first used to create a stable PDA primer layer, while the second step utilized a significantly lower concentration of dopamine (2 mg ml⁻¹) to promote the formation and deposition of large aggregates of PDA nanoparticles. Gentle shaking (70 rpm) was employed to increase the deposition of PDA nanoparticle aggregates and the formation of a thicker PDA coating with nano-scaled surface roughness (RMS = 110 …

Plant Stimuli-Responsive Biodegradable Polymers For The Use In Timed Release Fertilizer Coatings, Spencer Heuchan

Electronic Thesis and Dissertation Repository

The use of nitrogen-based fertilizers continues to accelerate with human population growth and increases in global food requirements. Enhanced efficiency fertilizers (EEFs) have been developed to improve the synchronization between nutrient supply and crop nutrient demand. However, many of the current controlled release fertilizers are coated with non-degradable polymers that contribute to accumulation of microplastics within ecosystems. This thesis describes research towards the development of a new class of fertilizer coatings using a self-immolative polymer known as poly (ethyl glyoxylate) (PEtG). PEtG itself does not have suitable properties to produce a viable coating but once blended with another degradable polyester …

Optimization Of Superhydrophobic Surface Production Using Ambient-Dried Silica-Based Aerogels, Elizabeth Donlon

Honors Theses

Superhydrophobic surfaces exhibit particular properties that make them functional in various anti-sticking, anti-contamination, self-cleaning and drag reduction applications. Though such surfaces are found in nature - most notably the lotus leaf - they are difficult to produce. There are numerous methods and techniques for fabricating superhydrophobic surfaces. One such method is the sol-gel method, in which aerogel, a highly porous and lightweight material that can be made hydrophobic or superhydrophobic, is coated onto a surface. The purpose of this project is to devise a simple and repeatable procedure for making hydrophobic silica aerogel coatings that can be used for drag …

Electrochemical Performance Of Moo2-C Composite Coatings, Quan-Yi Li, Qi Yang, Yan-Hong Zhao

Journal of Electrochemistry

The molybdenum dioxide-carbon(MoO₂-C)composite coatings on the surface of Cu foils were prepared by simple knife coating route and followed by sintering in vacuum. The morphology, composition, structure and electrochemical performance of the MoO₂-C composite coatings were investigated. The results demonstrated that the MoO₂-C composite coatings consist of MoO₂ nano-particles with monoclinic crystal structure and amorphous carbon. Some MoO₂ nano-particles with a size range of 5-30nm were loaded on the surface of carbon matrices; while some MoO₂ nano-particles with a size of ~5nm were encapsulated inside. The composite coatings showed porous structure …

Investigating Scalable Manufacturing Of High-Conductivity Wires And Coatings From Ultra-Long Carbon Nanotubes, Pouria Khanbolouki

Mechanical Engineering ETDs

Carbon nanotubes (CNTs) are a promising candidate for next generation of electrical wirings and electromagnetic interference (EMI) shielding materials due to their exceptional mechanical and electrical properties. Wires and coatings from ultralong nanotubes that are highly crystalline, well-aligned and densely packed can achieve this goal. High-performance CNT conductors will be relatively lightweight and resistant to harsh conditions and therefore can potentially replace current conductors in many industries including aerospace, automotive, gas and oil.

This thesis investigates a new manufacturing approach, based on conventional solution coating and wire drawing methods, to fabricate high conductivity wires and coatings from ultra-long carbon nanotubes. …

Usage Of Fomblin Y To Improve Water Repellence Of Surface Coatings, Shawn Pj Kirby, Jeffrey Alston, Andrew Guenthner

STAR Program Research Presentations

Fluoro-Decyl POSS (FDP) has shown strong potential as a water repellant surface coating. Additionally, Fomblin is a solvent believed to have the ability to control the crystallization of POSS compounds on surfaces. Controlling the crystallization is key to improving water repelling abilities of surfaces. Thus, dip coating FDP and Fomblin onto surfaces is being investigated for water repulsion, mechanical stability, and deposition feasibility. First, temperature dependence of solubility of Fluoro-Decyl POSS in Fomblin was tested using Dynamic Light Scattering. Relative water repelling abilities of different coatings were determined by measuring contact angle of surfaces with water. Coatings with and without …

Surface Structure And Electrochemical Performance Of Zno Coated Lini1/3Co1/3Mn1/3O2, Chang-Wei Liu, Yu Wang, Yu-Zhong Guo, Lu-Lu Dan, Jian-Hua Wang

Journal of Electrochemistry

The surface of LiNi_1/3Co_1/3Mn_1/3O₂ particles were modified by ZnO. Surface structure and electrochemical properties of the coated materials were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electrochemical tests. The results show that a ZnO coating affects the surface composition of LiNi_1/3Co_1/3Mn_1/3O₂ particles. The surface contents of nickel and manganese increase with the amount of ZnO coating. ZnO can react with LiNi_1/3Co_1/3Mn_1/3O₂ and a complex oxide is formed during the heat-treatment at above 400 ^oC. The …

Enhancing The High Rate Capability And Cycling Stability Of Limn2o4 By Coating Of Solid-State Electrolyte Linbo3, Zhijia Zhang, Shulei Chou, Qinfen Gu, Hua-Kun Liu, Huijun Li, Kiyoshi Ozawa, Jiazhao Wang

Australian Institute for Innovative Materials - Papers

To study the influence of solid state electrolyte coating layers on the performance of cathode materials for lithium-ion batteries in combination with organic liquid electrolyte, LiNbO3 coated Li1.08Mn1.92O4 cathode materials were synthesized by using a facile solid-state reaction method. The 0.06LiNbO3-0.97Li1.08Mn1.92O4 cathode exhibited an initial discharge capacity of 125 mAh g-1, retaining a capacity of 119 mAh g-1, at 25 oC, while at 55 oC, it exhibited an initial discharge capacity of 130 mAh g-1, retaining a capacity of 111 mAh g-1, both at a current density of 0.5 C (where 1 C is 148 mAh g-1). Very good rate …

Synthesis And Electrochemical Properties Of High-Capacity Cathode Material 0.08lico0.75Al0.25O2-0.92linio2, Ru-Ying Wang, Tian Qiu, Chong Mao, Wen-Sheng Yang

Journal of Electrochemistry

CoAl-LDH or Co(OH)₂ coated spherical Ni(OH)₂ precursors were obtained via a co-precipitation method at a constant pH. The mixtures of the precursors and LiOH.H₂O were annealed at high temperature in O₂ atmosphere, and then the cathode materials of 0.08LiCo_0.75Al_0.25O₂-0.92LiNiO₂, 0.08LiCoO₂-0.92LiNiO₂ and LiNiO₂ were synthesized. Effects of the coating layer were also studied. The results showed that the 0.08LiCo_0.75Al_0.25O₂-0.92LiNiO₂ material possessed the best rate and cycle life performance. The discharging capacities at 0.1C, 0.5C and 3C were …

Encapsulation Of High Temperature Phase Change Materials For Thermal Energy Storage, Rupa Nath

USF Tampa Graduate Theses and Dissertations

Thermal energy storage is a major contributor to bridge the gap between energy demand (consumption) and energy production (supply) by concentrating solar power. The utilization of high latent heat storage capability of phase change materials is one of the keys to an efficient way to store thermal energy. However, some of the limitations of the existing technology are the high volumetric expansion and low thermal conductivity of phase change materials (PCMs), low energy density, low operation temperatures and high cost. The present work deals with encapsulated PCM system, which operates at temperatures above 500°C and takes advantage of the heat …

Preparation And Performance Of Lifeo_2 Coated Nickel Oxide Cathode For Molten Carbonate Fuel Cells, Chun-Ming Wang, Fei Li, Ke-Ao Hu

Journal of Electrochemistry

A novel cathode for molten carbonate fuel cells was prepared by coating LiFeO 2 over the surface of porous NiO cathode by a simple combustion process. The analytical results of X-ray diffraction (XRD), energy dispersive analysis of X-ray (EDAX), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicated that the LiFeO 2 coating on the surface of NiO particles consisted of nonometer-sized LiFeO 2 grains and sintered tightly with the NiO particles. The LiFeO 2 coating dramatically reduced the contacting area of NiO with the carbonate melts, thus the solubility of NiO in the carbonate melts was decreased. Meanwhile, …

Electrochemical Evaluation On The Porosity Of Electroless Ni-P Alloy Coatings, Hong-Ying Yu, Dong-Bai Sun, Jing-Bing Huang, De-Jun Yang

Journal of Electrochemistry

By investigating the polarization curves of pure Ni P alloy,Ni P alloy coation and carbon steel in nitric acids with different concentrations,the sutable concentration of nitric acid for the evaluation of the porosity of Ni P alloy coatings has been determined and the coatings with different thickness have been evaluated.The results indicated that the nitric acid with 10 wt% concentration is the most suitable solution for the porosity of the coating by using electrochemical method.The polarization curve of Ni P alloy coating in 10% nitric acid can accurately reveal the porosity.With the decrease of the porosity of the coating,the corrosion …