Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2013. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Cataloged from student-submitted PDF version of thesis. / Includes bibliographical references (p. 51-52). / Production of materials which are limited by the amount available on the earth's surface follow a growth curve similar to the Avrami equation which governs the process of nucleation and growth. This thesis will analyze whether the product curve follows not only the same path but the same steps as the Avrami model: initially slow growth during an introductory period, accelerated growth during market acceptance, and declining growth following market saturation. This thesis will use two materials, steel and aluminum, as a case study to further understand the applicability of the Avrami model to production forecasts of materials available in finite or limited amounts. The aim of this project was to provide producers of various materials a model to use to predict when it would be profitable to invest in and enter a market and when not to do so. The framework developed provides a well-behaved model for the initial two stages, introduction and market acceptance, and forecasts the transition point between those two stages. However, due to lack of current data as neither aluminum nor steel have reached market saturation, a fit for the final stage and a forecast for the transition from market acceptance to market saturation has not yet been determined. / by Marianna B. See. / S.B.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1993. / Vita. / Includes bibliographical references (leaves 117-128). / by Chrysanthe D. Terwilliger. / Ph.D.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2016. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Cataloged from student-submitted PDF version of thesis. / Includes bibliographical references. / The intermittent nature of renewable energy sources requires a clean, scalable means of converting and storing energy. Water electrolysis can sustainably achieve this goal by storing energy in the bonds of oxygen and hydrogen molecules. The efficiency of this storage-conversion process is largely determined by the kinetic overpotential required for the oxygen evolution and reduction reactions (OER and ORR), respectively. This thesis focuses on transition metal oxides as alternative oxygen catalysts to costly and scarce noble metals. In order to develop descriptors to improve catalytic activity, thus reducing material cost for commercial technologies, this work studies fundamental processes that occur on model catalyst systems. Electrochemical studies of epitaxial oxide thin films establish the intrinsic activity of oxide catalysts in a way that cannot be realized with polydisperse nanoparticle systems. This thesis has isolated the activity of the catalyst on a true surface-area basis, enabling an accurate comparison of catalyst chemistries, and also revealed how different terminations and structures affect the kinetics. These studies of epitaxial thin films are among the first to probe phenomena that are not straightforward to isolate in nanoparticles, such as the role of oxide band structure, interfacial charge transfer (the "ligand" effect), strain, and crystallographic orientation. In addition, these well-defined surfaces allow spectroscopic examinations of their chemical speciation in an aqueous environment by using ambient pressure X-ray photoelectron spectroscopy. By quantifying the formation of hydroxyl groups, we compare the relative affinity of different surfaces for this key reaction intermediate in oxygen electrocatalysis. The strength of interaction with hydroxyls correlates inversely with activity, illustrating detrimental effects of strong water interactions at the catalyst surface. This fundamental insight brings molecular understanding to the wetting of oxide surfaces, as well as the role of hydrogen bonding in catalysis. Furthermore, understanding of the mechanisms of oxygen electrocatalysis guides the rational design of high-surface-area oxide catalysts for technical application. / by Kelsey A. Stoerzinger. / Ph. D.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1994. / Includes bibliographical references (leaves 47-48). / by Nicole Danielle B. Lazo. / M.S.

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1997. / Vita. / Includes bibliographical references (leaves 288-290). / by Tadashi Imai. / Sc.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2012. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Cataloged from student submitted PDF version of thesis. / Includes bibliographical references (p. 140-149). / Lithium-battery technologies have promising potentials to enable efficient energy distribution, sustainable transportation systems, and the widespread of renewable energy. One of the most critical challenges that limits their further advances is the limited ability to design efficient interfacial and surface chemistries due to the lack of fundamental understanding of reaction mechanisms. This thesis aimed to develop the fundamental understanding and design principles of oxide and metal surfaces for conventional Li-ion batteries and next generation, high-energy Li-air (or Li-O2) batteries. Fundamental approaches involving electrochemical characterizations, advanced spectroscopic and microscopic techniques were used to probe the interfacial and surface reactions of these batteries. The criteria for efficient electrode-electrolyte interfaces for Li-ion batteries were identified by examining the working mechanism of "AlPO4" nanoparticle coatings on enhancing the cycle life and energy efficiency of LiCoO2 batteries. SEM, XRD and XPS revealed that the "AlPO4" nanoparticles promote the formation of Co-Al-O-F species on the LiCoO2 particle surfaces as protection layers against electrolyte decomposition and oxygen loss from the lattice. This highlights the importance of metal oxyfluoride species toward material stability and cell efficiency. The reaction kinetics, catalyst effects and reaction mechanism of Li-O2 batteries were investigated by developing electrochemical model systems i.e., rotating disk electrode and Li2O2-filled composite electrodes, to quantify the intrinsic catalytic activity of nonaqueous oxygen reduction (ORR) and oxygen evolution reactions (OER). We found that the Li+-ORR activity is in order of Pd > Pt > Ru ~ Au > C, exhibiting a volcano-type dependence as a function of the oxygen adsorption energy of the catalyst surface. This volcano dependence suggests that the oxygen adsorption energy of the catalyst can serve as the ORR activity descriptor for designing highly active ORR catalyst for Li-O2 batteries. In addition, the application of Au nanoparticles was found to significantly increase the rate capability of the Li-O2 cells by enhancing the intrinsic ORR activity and influencing the structures of the discharge products. The catalyst effects on the charge reaction (OER), or Li2O2-decomposition reaction, were studied by potentiostatically oxidizing the Li2O2-filled composite electrodes with various catalysts. It is found that the electro-oxidation of Li2O2 can be significantly catalysed by the presence of Pt/C. With insights obtained from the model system studies, we designed bimetallic PtAu nanoparticles as bifunctional catalysts for Li-O2 batteries. Interestingly, the PtAu/C catalyst exhibits similar discharge profile to the Au/C and mirrors the charge activity of the Pt/C catalyst, achieving a remarkable round-trip efficiency (~75%) for rechargeable Li-O2 batteries. / by Yi-Chun Lu. / Ph.D.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2017. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 149-160). / The preform-to-fiber thermal drawing method is a versatile process that allows the fabrication of polymer or glass-based fibers with complex multimaterial internal structures, which grant them functions ranging from optical transmission to chemical detection. However, while a wide range of materials have been successfully drawn in various phases - such as metals, semiconductors, and ferroelectric polymers - the overall structure of the fiber is typically axially-invariant and the incorporation of heterogeneous materials with isotropic microstructures such as porous domains has remained elusive thus far. In this thesis we investigate the use of in-fiber phase separation as a means to control the microstructure of different components within thermally-drawn fibers. In particular we propose a novel method based on controlled phase separation of a polymer solution that we use to embed isotropically porous polymeric domains inside multimaterial fibers. We achieve this by thermal-drawing a hollow polymer preform filled with a liquid polymer solution in its core. We later apply this method to the fabrication and characterization of scaffolds for neural regeneration. In addition, we show that the same principle can also be used to draw a functional lithium-ion fiber battery; a fiber device capable of electrochemical energy storage. Finally, we demonstrate how to produce structured Si-Ge spheres encapsulated within a silica cladding by inducing capillary breakup of a continuous Si-Ge core fiber in a strong axial thermal gradient. The thermal gradient causes a "kinetic phase separation" of the alloy, leading to structured Janus particles. / by Benjamin Grena. / Ph. D.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2008. / MIT Science Library copy: printed in leaves. / Also issued printed in leaves. / Includes bibliographical references (p. 74-78). / Synthetic polymer matrices or subtrata with tailored elastic properties provide a powerful method to direct biological cell' differentiation and foster cell multiplication. By changing the stiffness of the substrate, human mesenchymal stem cell (MSCs) could be directed along neuronal, muscle, or bone lineages. Matrix elastic modulus can also control anchorage dependent cell's motility, localization, tissue formation and organization. Besides that, synthetic materials such as biodegradable polymers offer a versatile alternative to naturally derived biopolymers. Their mechanical properties can be highly tailored and they are easy to synthesize and shape. Moreover, these platforms can be readily "biologically" fine-tuned toward a particular cell linage by incorporating well-documented parameters, which play crucial roles in cell-extra cellular matrix (ECM) signaling pathway, such as growth factor, surface topology and stimulation signal. Hence, these materials are suitable candidates to develop engineered matrices for stem cell culture, cell manipulating platforms in biological research and drug development. In this thesis, commercialization aspects of these engineered matrices for stem cell research, cell culture and drug development markets are evaluated both in USA and in Singapore markets. Technological barriers, intellectual property and a preliminary cost model are analyzed. A business plan is presented and discussed for applications in both the stem cell research and the drug screening markets. Although these two markets are ill-defined, both of them are growing rapidly and appear to be very promising. A review of the technology itself led to the conclusion that the matrix is capable of induce anchorage dependent cell into specific lineage but the success rate is not yet quantified and further research need to be done to achieve good reproducibility and to meet the required efficacy of the industry. / by Vu Nguyen Tuan Ha. / M.Eng.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1988. / On t.p. "c̳" is subscript. / Includes bibliographical references. / by Joanna Marie McKittrick. / Ph.D.

Thesis. (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1988. / Bibliography: leaves 200-205. / by Peter Kenneth Moon. / Ph.D.