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Full-Text Articles in Materials Science and Engineering

Aps March Meeting 2020: Undergraduate-Friendly Research In Soft Matter And Beyond, Vianney Gimenez-Pinto May 2020

Aps March Meeting 2020: Undergraduate-Friendly Research In Soft Matter And Beyond, Vianney Gimenez-Pinto

Title III Professional Development Reports

The in-person APS March Meeting 2020 taking place in Denver during March 02-06, 2020 was canceled in the last minute out of Covid-19 concerns for the well-being of the scientific community as well as the population of the city of Denver and the state of Colorado. Nevertheless, well-planned logistics by the physics community and the APS leadership, allowed attendants to share their findings, presenting their research works to their peers, and continuing the work towards the advancement of science. Given the historical and on-going under-representation of students of color in science and technology at all academic levels, there is a …

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Experimental Performance Evaluation Of A Hyper-Branched Polymer Electrolyte For Rechargeable Li-Air Batteries, Susanta K. Das, Joel Berry, Abhijit Sarkar May 2020

Experimental Performance Evaluation Of A Hyper-Branched Polymer Electrolyte For Rechargeable Li-Air Batteries, Susanta K. Das, Joel Berry, Abhijit Sarkar

Mechanical Engineering Publications

A hyper-branched polymer (HBP) electrolyte is synthesized for rechargeable lithium-air (Li-air) battery cell and experimentally evaluated its performance in actual battery cell environment. Several real-world battery cells were fabricated with synthesized HBP electrolyte, pure lithium metal as anode and an oxygen permeable air cathode to evaluate reproducibility of the rechargeable Li-air battery cell. The effect of various conditions such as various HBP based electrolytes, discharge current −0.1~0.5 mA, cathode preparation processes and carbon contents on the battery cell performance were experimentally evaluated using the fabricated battery cells under dry air condition. Detailed HBP electrolyte synthesis procedures and experimental performance evaluation …

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Parametric Nasopharyngeal Swab For Sampling Covid-19 And Other Respiratory Viruses: Open Source Design, Sla 3-D Printing And Uv Curing System, Nicole Gallup, Adam Pringle, Shane Oberloier, Nagendra Gautam Tanikella, Joshua M. Pearce May 2020

Parametric Nasopharyngeal Swab For Sampling Covid-19 And Other Respiratory Viruses: Open Source Design, Sla 3-D Printing And Uv Curing System, Nicole Gallup, Adam Pringle, Shane Oberloier, Nagendra Gautam Tanikella, Joshua M. Pearce

Michigan Tech Publications, Part 1

Access to nasopharyngeal swabs for sampling remain a bottleneck in some regions for COVID19 testing. This study develops a distributed manufacturing solution using only an open source manufacturing tool chain consisting of two types of open source 3-D printing and batch UV curing, and provides a parametric fully free design of a nasopharyngeal swab. The swab was designed using parametric OpenSCAD in two components (a head with engineered break point and various handles), which has several advantages: i) minimizing print time on relatively slow SLA printers, ii) enabling the use of smaller print volume open source SLA printers, iii) reducing …

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Effect Of Post-Consumer Content And Bioplastic Incorporation On Polymeric Resin In Consumer Applications, Shelby Bicknell May 2020

Effect Of Post-Consumer Content And Bioplastic Incorporation On Polymeric Resin In Consumer Applications, Shelby Bicknell

Electronic Theses & Dissertations

Controversy surrounds the use of plastic products, primarily due to their potentially negative impact on the environment at the end of their lifecycle. The most widely used plastics are manufactured from petrochemicals such as petroleum, coal or natural gas. Petrochemical plastics are not able to readily breakdown in the environment, which aggravates the existing pollution problems. Fortunately, there are eco-friendly alternatives to petrochemical-based plastics. Bioplastics may be derived from renewable sources, biodegradable, or both. Bio-based plastics are plastics that may be derived from renewable biomass sources including, but not limited to, vegetable oils, cornstarch, straw, woodchips, and food waste. They …

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First-Principles Studies Of Anion Engineering In Functional Ceramics, Steven Timothy Hartman May 2020

First-Principles Studies Of Anion Engineering In Functional Ceramics, Steven Timothy Hartman

McKelvey School of Engineering Graduate Student Theses & Dissertations

Ceramic materials display a wide variety of valuable properties, such as ferroelectricity, superconductivity, and magnetic ordering, due to the partially covalent bonds which connect the cations and anions. While many breakthroughs have been made by mixing multiple cations on a sublattice, the equivalent mixed-anion ceramics have not received nearly as much attention, despite the key role the anion plays in the materials’ properties. There is great potential for functional ceramics design using anion engineering, which aims to tune the materials properties by adding and removing different types of anions in existing classes of ceramic materials. In this dissertation, I present …

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Scalable Synthesis Of Nanostructured Metal Oxide Films Using Aerosol Chemical Vapor Deposition For Energy Storage Applications, Clayton Kacica May 2020

Scalable Synthesis Of Nanostructured Metal Oxide Films Using Aerosol Chemical Vapor Deposition For Energy Storage Applications, Clayton Kacica

McKelvey School of Engineering Graduate Student Theses & Dissertations

As global energy consumption continues to rapidly increase, the need for new technologies to meet this demand in a sustainable way. Renewable sources such as solar and wind power are being increasingly utilized for electricity generation. However, the intermittent nature of these sources requires large-scale energy storage to reliably provide consistent power. Current grid-scale energy storage usually involves pumped hydroelectric systems, which are limited by location, or flywheel systems, which have limited use in high-power low-energy applications. Electrochemical storage solutions, such as lithium-ion batteries, provide robust energy storage that is not limited by location with a range of power and …

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Structure, Thermophysical Properties Of Liquids, And Their Connection With Glass Formability, Rongrong Dai May 2020

Structure, Thermophysical Properties Of Liquids, And Their Connection With Glass Formability, Rongrong Dai

McKelvey School of Engineering Graduate Student Theses & Dissertations

Metallic glasses have drawn significant attention due to their unique properties, such as high strength, excellent elastic energy storage capacity, and versatile processability. However, why some liquids can easily form metallic glasses while others donմ is still unclear. Since metallic glasses are formed when liquids are cooled fast enough to bypass crystallization, we hope to better understand glass formation by investigating the structural evolution and thermophysical properties of the liquids as they are cooled toward the glass transition. Multiple molecular dynamics simulations suggest a crossover temperature for the dynamics near the liquidus temperature, which corresponds to the onset of cooperative …

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Effects Of Hard-To-Soft Segment Ratios On The Synthesis And Physico-Mechanical Properties Of Polyurethane Films, Aaron C. Wilson May 2020

Effects Of Hard-To-Soft Segment Ratios On The Synthesis And Physico-Mechanical Properties Of Polyurethane Films, Aaron C. Wilson

Mechanical Engineering Theses

Blood-contacting cardiovascular stents often induce a secondary clotting event due to unrestricted enzymatic activities. The use of hemocompatible polyurethane coatings on these implantable devices is one of the most promising methods to reduce device rejection. In this study, four commercial polyurethane films of various thicknesses and compositions were evaluated for their anticoagulation properties. Results suggested that these films exhibited excellent thermal and physico-mechanical properties while capable of increasing contact time with blood plasma by over a thousand-fold as compared to a control surface. Due to the unknown structure and composition of these commercial films, polyurethane samples were synthesized from toluene …

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Applied-Force Oscillations In Avalanche Dynamics, Louis W. Mcfaul, Gregory Sparks, Jordan Sickle, Jonathan T. Uhl, Wendelin J. Wright, Robert Maass, Karin A. Dahmen May 2020

Applied-Force Oscillations In Avalanche Dynamics, Louis W. Mcfaul, Gregory Sparks, Jordan Sickle, Jonathan T. Uhl, Wendelin J. Wright, Robert Maass, Karin A. Dahmen

Faculty Journal Articles

Until now most studies of discrete plasticity have focused on systems that are assumed to be driven by a monotonically increasing force; in many real systems, however, the driving force includes damped oscillations or oscillations induced by the propagation of discrete events or “slip avalanches.” In both cases, these oscillations may obscure the true dynamics. Here we effectively consider both cases by investigating the effects of damped oscillations in the external driving force on avalanche dynamics. We compare model simulations of slip avalanches under mean-field dynamics with observations in slip-avalanche experiments on slowly compressed micrometer-sized Au specimens using open-loop force …

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Fabrication Of Nanoscale Columnar Diodes By Glancing Angle Deposition, Jacob D. Weightman May 2020

Fabrication Of Nanoscale Columnar Diodes By Glancing Angle Deposition, Jacob D. Weightman

Macalester Journal of Physics and Astronomy

Glancing angle deposition (GLAD) is a process in which thin films are deposited onto a substrate with obliquely incident vapor together with precisely controlled azimuthal substrate rotation. Ballistic shadowing effects due to the oblique incidence produce nanoscale structures, and a variety of feature shapes, including tilted columns, helices, and vertical columns can be achieved by varying the azimuthal rotation during the deposition process. Due to this control of morphology and the compatibility of the process with a wide variety of materials, GLAD films have found applications in a variety of fields including sensing, photonics, photovoltaics, and catalysis, where they are …

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Electrospun Silk-Boron Nitride Nanofibers With Tunable Structure And Properties., Ye Xue, Xiao Hu May 2020

Electrospun Silk-Boron Nitride Nanofibers With Tunable Structure And Properties., Ye Xue, Xiao Hu

College of Science & Mathematics Departmental Research

In this study, hexagonal boron nitride (h-BN) nanosheets and Bombyx mori silk fibroin (SF) proteins were combined and electrospun into BNSF nanofibers with different ratios. It was found that the surface morphology and crosslinking density of the nanofibers can be tuned through the mixing ratios. Fourier transform infrared spectroscopy study showed that pure SF electrospun fibers were dominated by random coils and they gradually became α-helical structures with increasing h-BN nanosheet content, which indicates that the structure of the nanofiber material is tunable. Thermal stability of electrospun BNSF nanofibers were largely improved by the good thermal stability of BN, and …

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Dynamic Characterization Of Duroprotect, A Fiber-Reinforced Ballistics Composite, Ivy A. Turner May 2020

Dynamic Characterization Of Duroprotect, A Fiber-Reinforced Ballistics Composite, Ivy A. Turner

Honors Theses

Dynamic characterization of materials has become increasingly common, as it is important to understand how materials behave under sudden loads. Understanding these properties can aid in material selection for novel designs. DuroProtect, a fiber-reinforced ballistics composite developed by Rӧchling, was tested for its dynamic properties at high strain-rates. The Split Hopkinson Pressure Bar (SHPB) test was used to obtain dynamic properties at high strain-rates under compressive loading conditions. Tests were initially conducted to validate force equilibriums for each sample. The data measured from the strain gages mounted on the incident and transmission bars and the elastic wave propagation theories yields …

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Comparative Analysis And Dynamic Response Of Garolites Under Temperature Spectrum Using Low Velocity Impact Test, Birendra Chaudhary May 2020

Comparative Analysis And Dynamic Response Of Garolites Under Temperature Spectrum Using Low Velocity Impact Test, Birendra Chaudhary

Honors Theses

The purpose of this study was to examine the dynamic response of three different grades of garolites under the temperature spectrum. High-Temperature G-11 Sheet (HTG), Impact Resistance Garolite E-glass (HIG), and Economical Garolite (EG) were tested using an Instron Dynatup 8250 impact tester. Three specimens were used for all three composites and were tested at 6 different temperatures, -10oC, 25oC, 50oC, 100oC, 150oC and 200oC using the Low-Velocity Impact Machine with 20 Kip punch shear load cell. The results showed that HIG had the highest resistance to punch …

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Product Realization Capstone: Element Proof Safety Steps For Willie Price Lab School, Catherine Thomas, Allan Heuerman, Jared Mumme May 2020

Product Realization Capstone: Element Proof Safety Steps For Willie Price Lab School, Catherine Thomas, Allan Heuerman, Jared Mumme

Honors Theses

The purpose of this document is to describe the process we took to complete our capstone which paired the Center for Manufacturing Excellence with the Willie Price Lab School. The goal of the capstone was to remake step stools for the students of Willie Price, as the last stools failed to withstand weather damage. However, with the COVID-19 pandemic, plans were hindered, shifting the goal from actually producing the steps to creating instructions so that a younger Center for Manufacturing class could complete the production at a later date. Standardized Work Instructions, a detailed production plan, and engineering drawings were …

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The Development Of All Solid-State Optical Cryo-Cooler, Junwei Meng May 2020

The Development Of All Solid-State Optical Cryo-Cooler, Junwei Meng

Optical Science and Engineering ETDs

This dissertation describes the development of an all solid-state optical cryo-cooler. Crystals of 10% wt. ytterbium-doped yttrium lithium fluoride (Yb3+:YLF) are used to cool an infrared HgCdTe sensor payload to an absolute temperature below 135 K, equivalent to delta T equal 138 K below ambient. This record level of cooling is accomplished with a single stage, in a completely vibration-free environment, with a corresponding cooling power of 190 mW. This milestone is made possible by the design and fabrication of an undoped YLF thermal link that efficiently shields the payload with a non-right angle kink from intense anti-Stokes …

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Bulk Properties Correlated To The Hydrogen Bond Organization In Dendrimers, Hyperbranched Polymers, And Linear Polymers, Beibei Chen May 2020

Bulk Properties Correlated To The Hydrogen Bond Organization In Dendrimers, Hyperbranched Polymers, And Linear Polymers, Beibei Chen

Dissertations

Although a lot of research was conducted on dendritic polymers, our understanding of their structure-property is still limited. Our previous study, which focused on a family of dendritic polymers based on 2,2-bis(hydroxymethyl) propionic acid (bis-MPA) as a monomer, discovered unique hydrogen bond organizations contributed by their dendritic structures. However, the influence of the H-bond organization on bulk properties has yet to be understood. The goal of this dissertation is to elucidate the correlation between the H-bond organization with the dielectric and volumetric properties of bis-MPA based dendritic polymers, with an emphasis on developing a fundamental understanding of to what extent …

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Optically Pumped Spin Polarization As A Probe Of Many-Body Thermalization, Daniela Pagliero, Pablo R. Zangara, Jacob Henshaw, Ashok Ajoy, Rodolfo H. Acosta, Jeffrey A. Reimer, Alexander Pines, Carlos A. Meriles May 2020

Optically Pumped Spin Polarization As A Probe Of Many-Body Thermalization, Daniela Pagliero, Pablo R. Zangara, Jacob Henshaw, Ashok Ajoy, Rodolfo H. Acosta, Jeffrey A. Reimer, Alexander Pines, Carlos A. Meriles

Publications and Research

Disorder and many body interactions are known to impact transport and thermalization in competing ways, with the dominance of one or the other giving rise to fundamentally different dynamical phases. Here we investigate the spin diffusion dynamics of 13C in diamond, which we dynamically polarize at room temperature via optical spin pumping of engineered color centers. We focus on low-abundance, strongly hyperfine-coupled nuclei, whose role in the polarization transport we expose through the integrated impact of variable radio-frequency excitation on the observable bulk 13C magnetic resonance signal. Unexpectedly, we find good thermal contact throughout the nuclear spin bath, …

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Development Of Multi-Axial Fatigue Retrofits For Lock Gate Components, Logan Verkamp May 2020

Development Of Multi-Axial Fatigue Retrofits For Lock Gate Components, Logan Verkamp

Graduate Theses and Dissertations

Lock gates are essential infrastructure components to the United State (US) supply chain. They create large cost savings and environmental benefits when compared with traditional methods of transport (freight and rail). Because of the large quantity of goods and dependence on these shipping chains, the US economy can be drastically affected by an unexpected gate closure. Unfortunately, many lock gates within the US have reached or exceeded their designed life. Due to the intensity of cyclic loads and the environment, fatigue cracks have become a prominent issue. Developed cracks near the pintle region (a joint which the gate rotates and …

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Plasma Electrolytic Oxidation Of Titanium Under Constant Applied Voltage, Joshua Paul Twaddle May 2020

Plasma Electrolytic Oxidation Of Titanium Under Constant Applied Voltage, Joshua Paul Twaddle

Material Science and Engineering Theses - Archive

Plasma Electrolytic Oxidation (PEO) is a method capable of applying nonmetallic coatings to metallic substrates submerged in electrolyte via a plasma development under high voltage. The PEO technique is particularly useful in the coating of materials such as Ti-, Al-, and Mg-based alloys. In this study, the effects of varying processing voltage and time on oxide coating characteristics formed on pure titanium surfaces was investigated. First, it was necessary to prove that the selected electrolyte type and concentration could produce PEO coatings in a predictable fashion. Experiments were performed with constant current density by constantly controlling the voltage, so the …

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Single Step Fabrication Of Shape Morphing 3d Surfaces, Amirali Nojoomi May 2020

Single Step Fabrication Of Shape Morphing 3d Surfaces, Amirali Nojoomi

Material Science and Engineering Dissertations - Archive

Shape-changing materials that can adopt programmable 3-dimensional (3D) shapes offer promise for a wide range of applications. Form the formation of the leaves and flowers to the shaping of complex organs, the analogues of such shape-morphing 3D surfaces are abundant in nature. However, since the formation of such surfaces in biological systems is fundamentally different from that of human-made materials, replicating their complex morphologies, movements, and thereby functions remains a challenge. Inspired by living organisms, we introduce an approach, called digital light 4D printing (DL4P), that encodes thermosensitive 2D hydrogels with a specific pattern of network density and thus temperature-induced …

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Pollution Prevention Via Recovery Of Cerium (Iv) Oxide In Optics Company, Eugene Park, William Gallagher, Sydor Optics, Flint Creek Resources May 2020

Pollution Prevention Via Recovery Of Cerium (Iv) Oxide In Optics Company, Eugene Park, William Gallagher, Sydor Optics, Flint Creek Resources

Articles

Pollution prevention methods were applied at an optics manufacturer in an effort to improve recovery of a valuable polishing component, cerium oxide (ceria), 77% of which was lost to dragout and sewer discharge. Centrifugation and microfiltratiion were evaluated to develop a process that would increase recovery of used ceria, which would then be sent back to the ceria supplier for reclamation and reuse. Full-scale implementation included a high-speed centrifuge that operates continuously with a microfiltration system through recirculation in a single process tank. Sydor Optics has improved ceria recovery from 23% to 48%, saving thousands of dollars annually.

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Monolithic Chalcogenide Optical Nanocomposites Enable Infrared System Innovation: Gradient Refractive Index Optics, Myungkoo Kang, Laura Sisken, Charmayne Lonergan, Andrew Buff, Anupama Yadav, Claudia Goncalves, Cesar Blanco, Peter Wachtel, J. David Musgraves, Alexej V. Pogrebnyakov, Erwan Baleine, Clara Rivero-Baleine, Theresa S. Mayer, Carlo G. Pantano, Kathleen A. Richardson May 2020

Monolithic Chalcogenide Optical Nanocomposites Enable Infrared System Innovation: Gradient Refractive Index Optics, Myungkoo Kang, Laura Sisken, Charmayne Lonergan, Andrew Buff, Anupama Yadav, Claudia Goncalves, Cesar Blanco, Peter Wachtel, J. David Musgraves, Alexej V. Pogrebnyakov, Erwan Baleine, Clara Rivero-Baleine, Theresa S. Mayer, Carlo G. Pantano, Kathleen A. Richardson

Materials Science and Engineering Faculty Research & Creative Works

The size and weight of conventional imaging systems is defined by costly non-planar lenses and the complex lens assemblies required to minimize optical aberrations. The ability to engineer gradient refractive index (GRIN) optics has the potential to overcome constraints of traditional homogeneous lenses by reducing the number of components in optical systems. Here, an innovative strategy to realize this goal based on monolithic GRIN media created in Ge-As-Se-Pb chalcogenide infrared nanocomposites is presented. A gradient heat treatment to spatially modulate the volume fraction of high refractive index Pb-rich nanocrystals within a glass matrix is utilized, providing a GRIN profile while …

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Spherical Cavity Expansion Approach For The Study Of Rigid-Penetrator’S Impact Problems, Mario Buchely, Alejandro Marañon May 2020

Spherical Cavity Expansion Approach For The Study Of Rigid-Penetrator’S Impact Problems, Mario Buchely, Alejandro Marañon

Materials Science and Engineering Faculty Research & Creative Works

In recent years, Spherical Cavity Expansion (SCE) theory has been extensively utilized to model dynamic deformation processes related to indentation and penetration problems in many fields. In this review, the SCE theory is introduced by explaining the different mathematical features of this theory, its solution, and a potential application to model the penetration of a rigid penetrator into a deformable target. First, a chronologically literature review of the most common models used to study this kind of penetration problems is introduced, focusing on the SCE theory. Then, the engineering model of penetration is presented using the SCE approach. The model …

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Characterization Of Mechanical, Thermodynamic And Surface Properties Of The Butterfly Proboscis, Tatiana Stepanova May 2020

Characterization Of Mechanical, Thermodynamic And Surface Properties Of The Butterfly Proboscis, Tatiana Stepanova

All Theses

The butterfly proboscis is a fascinating fiber designed to probe and transport fluids. The built-in sensors and actuators make this fiber multifunctional. The proboscis consists of 2 hollow C-shaped tubes that are united when the butterfly comes out of the pupa. A single galea consists of a solid cuticular wall, muscles, nerves, and tracheae. The proboscis cuticular wall is mainly composed of polymers and small amounts of metals and non-metals. The proboscis is a porous material, and its water content is high, up to 50%. When the butterfly is not hungry, its proboscis is tightly coiled; when the butterfly is …

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Additive Manufacturing And How 3d Printing Is Fighting Covid-19, Raghavan Srinivasan, Ahsan Mian, Joy Gockel, Laura M. Luehrmann May 2020

Additive Manufacturing And How 3d Printing Is Fighting Covid-19, Raghavan Srinivasan, Ahsan Mian, Joy Gockel, Laura M. Luehrmann

Mechanical and Materials Engineering Faculty Publications

This is the fourth installment in the Shelter in Place (SiP) Lecture series. This installment covers the creative ways that 3D printing has supported efforts to combat the pandemic. It covers the basics of what 3D printing is, some of the various creative projects that have used 3D printing to combat the pandemic, among other topics and questions by the pandemic.

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Hydrolytic Degradation Study Of Polyphosphazene-Plga Blends, Riley Blumenfield May 2020

Hydrolytic Degradation Study Of Polyphosphazene-Plga Blends, Riley Blumenfield

Honors Scholar Theses

The synthesis and in vitro degradation analysis of thin films of poly[(glycineethylglycinato)75(phenylphenoxy)25phosphazene]
(PNGEG75PhPh25) and poly[(ethylphenylalanato)25(glycine-
ethylglycinato)75phosphazene] (PNEPA25GEG75) blended with poly(lactic-co-glycolic acid) (PLGA) was conducted to determine the blends’ potential for use as scaffolding materials for tissue regeneration applications. The samples were synthesized with glycylglycine ethyl ester (GEG) acting as the primary substituent side group, with cosubstitution by phenylphenol (PhPh) and phenylalanine ethyl ester (EPA) to make the final product [1]. Blends of 25% polyphosphazene, 75% PLGA and 50% polyphosphazene, 50% PLGA were …

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Synthesis Of Nickel-Titanium Intermetallic Surface Coatings Via Electrolytic Plasma Processing, Brody Allen Moore May 2020

Synthesis Of Nickel-Titanium Intermetallic Surface Coatings Via Electrolytic Plasma Processing, Brody Allen Moore

Material Science and Engineering Theses - Archive

Electrolytic plasma processing (EPP) is an environmentally friendly surface cleaning and deposition technique. Dependant on circuit polarity, anionic or cationic species can be deposited from an aqueous electrolyte bridge, resulting in characteristic nanograin surface morphology and very high deposition rates. This work was conducted to study the EPP process, develop optimal parameters for the synthesis of very hard surface coatings, and study the resultant physical and electrochemical properties of produced titanium-nickel intermetallic surfaces. This study focuses on Ni deposited onto pure Ti surfaces for improvement of surface wear, hardness, and corrosion properties while retaining uncompromised Ti bulk characteristics. The surface …

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Investigation On The Morphology Of Charge-Transfer Complexes In Low Density Polyethylene, Wade Korf May 2020

Investigation On The Morphology Of Charge-Transfer Complexes In Low Density Polyethylene, Wade Korf

Master's Theses

Fillers are used ubiquitously throughout the fields of polymer and material science to overcome many inherent limitations to polymeric materials (i.e. poor stiffness or strength) and to expand their potential applications. There is a need to develop controllable particle architectures to better understand fundamental structure-property relationships in particle reinforced polymer composites. Charge-transfer complexes (CTCs) can assemble in situ into various needle and dendritic shapes via simple fabrication processes and at low loading levels. In this study, the effect of tetrathiafulvalene (TTF) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) CTC crystallites of various shapes and sizes on composite mechanical properties was investigated in an LDPE …

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Co-Assembly Behavior Of Neutral And Zwitterionic Amphiphilic Block Copolymers In The Fabrication Of Glassy Polymer Vesicles, Elina Ghimire May 2020

Co-Assembly Behavior Of Neutral And Zwitterionic Amphiphilic Block Copolymers In The Fabrication Of Glassy Polymer Vesicles, Elina Ghimire

Honors Theses

Polymersomes, also known as polymer vesicles, are hollow capsules fabricated through the solution assembly of amphiphilic block copolymers. Polymer vesicles have garnered a great deal of interest in materials science because of their potential application in areas such as drug delivery, diagnostics and imaging, gene therapy, and as nanoreactors. The goal of this project is to understand the factors that affect the arrangement of triblocks in vesicle membrane via the study of the co-assembly behavior of linear amphiphilic triblocks with different hydrophilic blocks. We investigated the self- and co-assembly behavior of amphiphilic triblock copolymers with neutral hydrophilic blocks. Moreover, we …

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Tailoring Photodegradation Rates Of Acetal-Containing Polymer Networks, Michael Sandoz May 2020

Tailoring Photodegradation Rates Of Acetal-Containing Polymer Networks, Michael Sandoz

Honors Theses

In this thesis, we explore the degradation of poly (thioether acetal) thermosets via a photoinduced thiol-catalyzed ß-scission of acetal linkages incorporated as network crosslink junctions. Specifically, a library of bis-allyl acetal-containing monomers derived from para-substituted benzaldehydes was synthesized and formulated into photopolymerizable thiol-ene resins with commercially available thiol monomers. By varying the electron donating or withdrawing nature of the monomer substituent, we explored the impact of substituent effects on the rate of polymer degradation. Furthermore, we compare the results to those expected from a classical Hammett-type relationship of substituent electronic effects. FTIR was employed to track the appearance of the …

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