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Description
One of the grand challenges of engineering is to provide access to clean water because it is predicted that by 2025 more than two thirds of the world’s population will face severe water shortages. To combat this global issue, our lab focuses on creating a novel composite membrane to recover potable water from waste. For use as the water-selective component in this membrane design Linde Type A zeolites were synthesized for optimal size without the use of a template. Current template-free synthesis of zeolite LTA produces particles that are too large for our application therefore the particle size was reduced in this study to reduce fouling of the membrane while also investigating the nanoparticle synthesis mechanisms. The time and temperature of the reaction and the aging of the precursor gel were systematically modified and observed to determine the optimal conditions for producing the particles. Scanning electron microscopy, x-ray diffraction, and energy dispersive x-ray analysis were used for characterization. Sub-micron sized particles were synthesized at 2 weeks aging time at -8°C with an average size of 0.6 micrometers, a size suitable for our membrane. There is a limit to the posterity and uniformity of particles produced from modifying the reaction time and temperature. All results follow general crystallization theory. Longer aging produced smaller particles, consistent with nucleation theory. Spinodal decomposition is predicted to affect nucleation clustering during aging due to the temperature scheme. Efforts will be made to shorten the effective aging time and these particles will eventually be incorporated into our mixed matrix osmosis membrane.
ContributorsKing, Julia Ann (Author) / Lind, Mary Laura (Thesis director) / Durgun, Pinar Cay (Committee member) / Chemical Engineering Program (Contributor) / Materials Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Immigrant families expect their children to go above and beyond since they have access to better facilities and opportunities in comparison to their home land. In my autobiographical works of art for my Barrett Honors Thesis project, I explore how my family has become more Americanized, yet still holds traditional values. I’ve focused on how differences in culture have molded different sets of morals between my parents, me, and my sibling. My series of graphite drawings on paper are a collection of milestones in my life. It may not be a completely fluid timeline but all the important points are present and the viewer can ponder what happened in snapshots of my life. The difference in culture is depicted through representations of clothing, posture, praying, religion, and subjects.
ContributorsChu, Amanda R (Author) / Hogden, Heidi (Thesis director) / Green, Heather (Committee member) / Materials Science and Engineering Program (Contributor) / School of Life Sciences (Contributor) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
With renewable energy on the rise, researchers have turned their funding and their focus towards new solar cell technologies, and perovskites are a major source of interest. This class of materials is particularly interesting due to their quick, simple synthesis as well as their physical and electrical superiority when compared to current silicon-based solar cells. Through this thesis, we will explore the synthesis of various types of perovskites and their subsequent characterization, which includes optical microscopy, photoluminescence spectroscopy, Raman microscopy, and X-ray diffraction. Analyzing two different perovskites both before and after a two-week period of storage revealed that while synthesis is indeed experiment-friendly, these materials have a concerning lack of stability even in ideal conditions.
ContributorsBuzas, Benjamin Joseph (Author) / Tongay, Sefaattin (Thesis director) / Muhich, Christopher (Committee member) / Materials Science and Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
The purpose of this project is to analyze the current state of cancer nanomedicine and its challenges. Cancer is the second most deadly illness in the United States after heart disease. Nanomedicine, the use of materials between 1 and 100 nm to for the purpose of addressing healthcare-related problems, is particularly suited for treating it since nanoparticles have properties such as high surface area-to-volume ratios and favorable drug release profiles that make them more suitable for tasks such as consistent drug delivery to tumor tissue. The questions posed are: What are the current nanomedical treatments for cancer? What are the technical, social, and legal challenges related to nanomedical treatments and how can they be overcome? To answer the questions mentioned above, information from several scientific papers on nanomedical treatments for cancer as well as from social science journals was synthesized. Based on the findings, nanomedicine has a wide range of applications for cancer drug delivery, detection, and immunotherapy. The main technical challenge related to nanomedical treatments is navigating through biological barriers such as the mononuclear phagocyte system, the kidney, the blood-brain barrier, and the tumor microenvironment. Current approaches to meeting this challenge include altering the size, shape, and charge of nanoparticles for easier passage. The main social and legal challenge related to nanomedical treatments is the difficulty of regulating them due to factors such as the near impossibility of detecting nanowaste. Current approaches to meeting this challenge include the use of techniques such as scanning tunneling microscopy and atomic force microscopy to help distinguish nanowaste from the surroundings. More research will have to be done in these and other areas to enhance a major cancer-fighting tool.
ContributorsAbraham, Alfred Francy (Author) / Brian, Jennifer (Thesis director) / Liu, Yan (Committee member) / Materials Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
Titanium dioxide is an essential material under research for energy and environmental applications, chiefly through its photocatalytic properties. These properties allow it to be used for water-splitting, detoxification, and photovoltaics, in addition to its conventional uses in pigmentation and sunscreen. Titanium dioxide exists in several polymorphic structures, of which the most common are rutile and anatase. We focused on anatase for the purposes of this research, due to its promising results for hydrolysis.
Anatase exists often in its reduced form (TiO2-x), enabling it to perform redox reactions through the absorption and release of oxygen into/from the crystal lattice. These processes result in structural changes, induced by defects in the material, which can theoretically be observed using advanced characterization methods. In situ electron microscopy is one of such methods, and can provide a window into these structural changes. However, in order to interpret the structural evolution caused by defects in materials, it is often necessary and pertinent to use atomistic simulations to compare the experimental images with models.
In this thesis project, we modeled the defect structures in anatase, around oxygen vacancies and at surfaces, using molecular dynamics, benchmarked with density functional theory. Using a “reactive” forcefield designed for the simulation of interactions between anatase and water that can model and treat bonding through the use of bond orders, different vacancy structures were analyzed and simulated. To compare these theoretical, generated models with experimental data, the “multislice approach” to TEM image simulation was used. We investigated a series of different vacancy configurations and surfaces and generated fingerprints for comparison with TEM experiments. This comparison demonstrated a proof of concept for a technique suggesting the possibility for the identification of oxygen vacancy structures directly from TEM images. This research aims to improve our atomic-level understanding of oxide materials, by providing a methodology for the analysis of vacancy formation from very subtle phenomena in TEM images.
Anatase exists often in its reduced form (TiO2-x), enabling it to perform redox reactions through the absorption and release of oxygen into/from the crystal lattice. These processes result in structural changes, induced by defects in the material, which can theoretically be observed using advanced characterization methods. In situ electron microscopy is one of such methods, and can provide a window into these structural changes. However, in order to interpret the structural evolution caused by defects in materials, it is often necessary and pertinent to use atomistic simulations to compare the experimental images with models.
In this thesis project, we modeled the defect structures in anatase, around oxygen vacancies and at surfaces, using molecular dynamics, benchmarked with density functional theory. Using a “reactive” forcefield designed for the simulation of interactions between anatase and water that can model and treat bonding through the use of bond orders, different vacancy structures were analyzed and simulated. To compare these theoretical, generated models with experimental data, the “multislice approach” to TEM image simulation was used. We investigated a series of different vacancy configurations and surfaces and generated fingerprints for comparison with TEM experiments. This comparison demonstrated a proof of concept for a technique suggesting the possibility for the identification of oxygen vacancy structures directly from TEM images. This research aims to improve our atomic-level understanding of oxide materials, by providing a methodology for the analysis of vacancy formation from very subtle phenomena in TEM images.
ContributorsShindel, Benjamin Noam (Author) / Crozier, Peter (Thesis director) / Anwar, Shahriar (Committee member) / Singh, Arunima (Committee member) / Materials Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Graphene has the ability to advance many common fields, including: membranes, composites and coatings, energy, and electronics. For membranes, graphene will be used as a filter for desalination plants which will reduce the cost of desalination and greatly increase water security in developing countries. For composites and coatings, graphene's strength, flexibility, and lightweight will be instrumental in producing the next generation of athletic wear and sports equipment. Graphene's use in energy comes from its theorized ability to charge a phone battery in seconds or an electric car in minutes. Finally, for electronics, graphene will be used to create faster transistors, flexible electronics, and fully integrated wearable technology.
ContributorsSiegel, Adam (Author) / Adams, James (Thesis director) / Krause, Stephen (Committee member) / Materials Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The main objective of this project is to create a hydrogel based material system to capture and release CCRF-CEM Leukemia cancer cells via chemo-mechanical modulation. This system is composed of an aptamer-functionalized hydrogel thin film at the bottom of a microfluidic channel, which changes its film thickness as the temperature of the fluid in the system changes. The functionalized hydrogel film has been created as the primary steps to creating the microfluidic device that could capture and release leukemia cells by turning the temperature of the fluid and length of exposure. Circulating tumor cells have recently become a highly studied area since they have become associated with the likelihood of patient survival. Further, circulating tumor cells can be used to determine changes in the genome of the cancer leading to targeted treatment. First, the aptamers were attached onto the hydrogel through an EDC/NHS reaction. The aptamers were verified to be attached onto the hydrogel through FTIR spectroscopy. The cell capture experiments were completed by exposing the hydrogel to a solution of leukemia cells for 10 minutes at room temperature. The cell release experiments were completed by exposing the hydrogel to a 40°C solution. Several capture and release experiments were completed to measure how many cells could be captured, how quickly, and how many cells captured were released. The aptamers were chemically attached to the hydrogel. 300 cells per square millimeter could be captured at a time in a 10 minute time period and released in a 5 minute period. Of the cells captured, 96% of them were alive once caught. 99% of cells caught were released once exposed to elevated temperature. The project opens the possibility to quickly and efficiently capture and release tumor cells using only changes in temperature. Further, most of the cells that were captured were alive and nearly all of those were released leading to high survival and capture efficiency.
ContributorsPaxton, Rebecca Joanne (Author) / Stephanopoulos, Nicholas (Thesis director) / He, Ximin (Committee member) / Gould, Ian (Committee member) / Materials Science and Engineering Program (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Solid-state lithium-ion batteries are a major area of research due to their increased safety characteristics over conventional liquid electrolyte batteries. Lithium lanthanum zirconate (LLZO) is a promising garnet-type ceramic for use as a solid-state electrolyte due to its high ionic conductivity. The material exists in two dierent phases, one that is cubic in structure and one that is tetragonal. One potential synthesis method that results in LLZO in the more useful, cubic phase, is electrospinning, where a mat of nanowires is spun and then calcined into LLZO. A phase containing lanthanum zirconate (LZO) and amorphous lithium occursas an intermediate during the calcination process. LZO has been shown to be a sintering aid for LLZO, allowing for lower sintering temperatures. Here it is shown the eects of internal LZO on the sintered pellets. This is done by varying the 700C calcination time to transform diering amounts of LZO and LLZO in electrospun nanowires, and then using the same sintering parameters for each sample. X-ray diraction was used to get structural and compositional analysis of both the calcined powders and sintered pellets. Pellets formed from wires calcined at 1 hour or longer contained only LLZO even if the calcined powder had only undergone the rst phase transformation. The relative density of the pellet with no initial LLZO of 61.0% was higher than that of the pellet with no LZO, which had a relative density of 57.7%. This allows for the same, or slightly higher, quality material to be synthesized with a shorter amount of processing time.
ContributorsLondon, Nathan Harry (Author) / Chan, Candace (Thesis director) / Tongay, Sefaattin (Committee member) / Department of Physics (Contributor) / Materials Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
The vastly growing field of supercomputing is in dire need of a new measurement system to optimize JMRAM (Josephson junction magnetoresistive random access memory) devices. To effectively measure these devices, an ultra-low-noise, low cost cryogenic dipping probe with a dynamic voltage range is required. This dipping probe has been designed by ASU with <100 nVp-p noise, <10 nV offsets, 10 pV to 16 mV voltage range, and negligible thermoelectric drift. There is currently no other research group or company that can currently match both these low noise levels and wide voltage range. Two different dipping probes can be created with these specifications: one for high-use applications and one for low-use applications. The only difference between these probes is the outer shell; the high-use application probe has a shell made of G-10 fiberglass for a higher price, and the low-use application probe has a shell made of AISI 310 steel for a lower price. Both types of probes can be assembled in less than 8 hours for less than $2,500, requiring only soldering expertise. The low cost and short time to create these probes makes wide profit margins possible. The market for these cryogenic dipping probes is currently untapped, as most research groups and companies that use these probes build their own, which allows for rapid business growth. These potential consumers can be easily reached by marketing these probes at superconducting conferences. After several years of selling >50 probes, mass production can easily become possible by hiring several technicians, and still maintaining wide profit margins.
ContributorsHudson, Brooke Ashley (Author) / Adams, James (Thesis director) / Anwar, Shahriar (Committee member) / Materials Science and Engineering Program (Contributor) / W. P. Carey School of Business (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Perovskite films are the future of solar cell technology as they are not only low cost to produce and lightweight but also have a 26% conversion efficiency. This is extremely close to the standard silicon solar cell. The key challenge limiting the commercialization potential of these films is their fragility and durability to outdoors conditions. This project investigates the mechanical and material properties of these perovskite materials in order to understand their future manufacturing capabilities. Through the use of a spin coater, blade coater, and a double cantilever beam testing set up, the fracture energy (or toughness), Gc, of Perovskite films is determined. Understanding the properties of these films can help manufacturers determine how to best make durable films that can be used in everyday energy generation. Furthermore, this study offers strategies to improve the fracture energy of these films by adding polymers and food-additive starches to the recipe. The findings collected in this project present a technique to study the mechanical properties of perovskite-based solar technology and films and further aid the technology to become commercially viable.
ContributorsBakshi, Kayshavi (Author) / Rolston, Nicholas (Thesis director) / Li, Muzhi (Committee member) / Barrett, The Honors College (Contributor) / Materials Science and Engineering Program (Contributor) / School of International Letters and Cultures (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2023-12