Matching Items (3)
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- All Subjects: Metals
- All Subjects: MOF
- Creators: Burt, Donald
- Creators: Close, Emily Charlotte
Description
Within recent years, metal-organic frameworks, or MOF’s, have gained a lot of attention in the materials research community. These micro-porous materials are constructed of a metal oxide core and organic linkers, and have a wide-variety of applications due to their extensive material characteristic possibilities. The focus of this study is the MOF-5 material, specifically its chemical stability in air. The MOF-5 material has a large pore size of 8 Å, and aperture sizes of 15 and 12 Å. The pore size, pore functionality, and physically stable structure makes MOF-5 a desirable material. MOF-5 holds applications in gas/liquid separation, catalysis, and gas storage. The main problem with the MOF-5 material, however, is its instability in atmospheric air. This inherent instability is due to the water in air binding to the zinc-oxide core, effectively changing the material and its structure. Because of this material weakness, the MOF-5 material is difficult to be utilized in industrial applications. Through the research efforts proposed by this study, the stability of the MOF-5 powder and membrane were studied. MOF-5 powder and a MOF-5 membrane were synthesized and characterized using XRD analysis. In an attempt to improve the stability of MOF-5 in air, methyl groups were added to the organic linker in order to hinder the interaction of water with the Zn4O core. This was done by replacing the terepthalic acid organic linker with 2,5-dimethyl terephthalic acid in the powder and membrane synthesis steps. The methyl-modified MOF-5 powder was found to be stable after several days of exposure to air while the MOF-5 powder exhibited significant crystalline change. The methyl-modified membrane was found to be unstable when synthesized using the same procedure as the MOF-5 membrane.
ContributorsAnderson, Anthony David (Author) / Lin, Jerry Y.S. (Thesis director) / Ibrahim, Amr (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Metal-organic frameworks (MOFs) are a new set of porous materials comprised of metals or metal clusters bonded together in a coordination system by organic linkers. They are becoming popular for gas separations due to their abilities to be tailored toward specific applications. Zirconium MOFs in particular are known for their high stability under standard temperature and pressure due to the strength of the Zirconium-Oxygen coordination bond. However, the acid modulator needed to ensure long range order of the product also prevents complete linker deprotonation. This leads to a powder product that cannot easily be incorporated into continuous MOF membranes. This study therefore implemented a new bi-phase synthesis technique with a deprotonating agent to achieve intergrowth in UiO-66 membranes. Crystal intergrowth will allow for effective gas separations and future permeation testing. During experimentation, successful intergrown UiO-66 membranes were synthesized and characterized. The degree of intergrowth and crystal orientations varied with changing deprotonating agent concentration, modulator concentration, and ligand:modulator ratios. Further studies will focus on achieving the same results on porous substrates.
ContributorsClose, Emily Charlotte (Author) / Mu, Bin (Thesis director) / Shan, Bohan (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
The purpose of this creative project is twofold: Firstly, to study various pattern-welding processes that have been used throughout history, and secondly, to attempt to create a piece or several pieces of art using the processes studied. Pattern-welding traditionally refers to the practice of creating forged laminates composed of alternating layers of two or more compositionally distinct metals. This term is typically used to specifically refer to these techniques when they are used for the creation of blades, with laminates made of high-phosphorus iron, low-phosphorus mild steel, and/or wrought iron, which was historically done to give the final weapon allegedly better mechanical properties (Thiele et al., 2015). This technique, while supposedly creating mechanically superior weapons in terms of durability and strength, also results in a unique, incredibly aesthetic visual effect. As the laminated billet of metals is twisted, deformed, etched, and polished, the different layers of metals become visible, resulting in a range of patterns depending on the deformation techniques used, and it was this aesthetic value that truly led to the widespread use of pattern-welding. Metals worked in this manner are colloquially known today as Damascus, although the process is technically distinct from true Damascus steel. For the purposes of this creative project, I will extend the concept of pattern-welding beyond strictly using iron and steel used to create swords, and include the similar artistic technique known as mokume-gane. Mokume-gane, which directly translates into English as “wood-grain metal” (Binnion, 2011), also involves forging alternating layers of different metals into a billet, but uses softer metals, historically silver, gold, copper, and alloys of the above. Mokume-gane, which has only relatively recently been used in the West, is the technique that I used to create my art pieces for this creative project.
ContributorsFox, Matthew Davis (Author) / Misquadace, Wanesia (Thesis director) / Burt, Donald (Committee member) / School of Earth and Space Exploration (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05