Thesis: S.M., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2017. / 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 (pages 95-99). / The design and validation of new alloys for engineering applications is limited by the speed at which materials may be tested. In particular, there exist few methods by which the thermal, mechanical, and structural properties of materials may be monitored in conditions that are dynamically changing their microstructure. These conditions, such as heat treatments, radiation exposure, or corrosive environments, are common when material performance needs to be validated. To offset this lack of capability, new non-destructive experimental tools must be developed to facilitate on-line, realtime testing of materials undergoing some type of evolution. In this thesis, a flexible, all-optical methodology known as dual heterodyne phase collection transient grating spectroscopy is developed for this purpose. This method adapts a traditional spectroscopic technique sensitive to thermal and mechanical properties for real-time use. A formalism is also developed to quantify both elastic and thermal transport properties of materials with second-scale resolution. These new tools are then used to study the short-timescale oxidation kinetics of Fe-12Cr-2Si, a model alloy with oxide layer formation properties similar to large classes of Fr-Cr alloys. By monitoring the effect of thin oxide layers on surface thermal transport, there exists a pathway to continuously determine the thickness of a tens of nanometers thick growing oxide layer in real-time. Despite the lack of clarity in the particular set of experimental results presented here, the potential for the methods developed in this thesis is large. In-situ materials testing of this type may allow for a drastic increase in the pace of materials development by reducing the need for post-evolution, destructive materials testing between each design iteration. / by Cody Andrew Dennett. / S.M.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1998. / Includes bibliographical references (leaves 214-230). / About 250,000 people undergo knee and hip arthroplasty each year in North America alone, with hundreds of thousands more receiving joints over the rest of the world. Two factors are key to the success of these implants: first, the quality of attachment of the prosthetic joint to the patient's bone, and second, the low generation of wear particles as the components of the prosthesis articulate against each other. This thesis is a study of both of these factors. First, the mechanism of bone apposition to hydroxyapatite (HA) coatings on Ti-6Al-4V was investigated via transmission electron microscopy (TEM). In this section of the study, Ti alloy cylinders were coated with HA by two different methods to yield three types of coatings - annealed and unannealed plasma-spray (PSHA) coatings and an annealed ion-beam assisted deposited (IBAD-HA) coating. These cylinders were implanted in trabecular bone in dogs from periods ranging from 3 hours to 14 days. Mechanical testing indicated that the bone/implant interface with the PSHA coated implants was significantly stronger than that with the IBAD-HA coated or uncoated Ti alloy implants. However, there were no differences in the degree of bone apposition to the three HA-coated materials; thus indicating that bone apposition is not a sufficient indicator of mechanical integrity of the bone/HA interface. In the second section of this study, the microstructural factors contributing to the observed wear properties of the oxide on Zr-2.5Nb were investigated via TEM. Zr-2.5Nb barstock which had been rotary-forged to impart an anisotropic microstructure was sectioned and oxidized in dry air at 600°C and 635°C for a variety of times ranging from 30 minutes to 40 hours. Cross-sections across the oxide/metal interface were observed via TEM. The oxide scale comprises primarily monoclinic zirconia, with small amounts of tetragonal zirconia. Evidence of a mixed oxide phase, 6Zr02.Nb205, was also observed. The microstructure of this oxide is dependent on oxidation temperature, the microstructure of the underlying metal, and oxide depth. Two oxide microstructures originating from beta-Zr grains in the alloy were also identified. A third study concerned the architecture and microstructure of naturally-derived and synthetic bone substitute materials (BSMs). While BSMs are used clinically to promote healing in large bone defects, they were useful to this study as a control for the organization of mineral in mature bone. Low voltage high resolution scanning electron microscopy (LVHRSEM) enabled observations of the three dimensional architecture of these materials which were then correlated with TEM observations. The crystallites in an anorganic bovine-derived BSM were organized in a hierarchical fashion which paralleled the organization of collagen. In contrast, the synthetic materials were organized in an isotropic network. The difference in organization was attributed to the formation of the mineral matrix of bone on an anisotropic collagen template. / by Valarie Ilene Benezra. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1994. / Includes bibliographical references (leaves 214-223). / by Frederick George Haubensak. / Ph.D.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2008. / Includes bibliographical references (leaf 24). / A study of the behavior of nanoparticles in the presence of solvent vapors is presented. Millimeter-scale films of gold nanoparticles, one nanometer thick, are treated with solvent vapors at various temperatures and the behavior of the nanoparticles is tracked over time using transmission electron microscopy. The ultimate goal of this processing is to repair defects such as grains, dislocations, and vacancies in the original superlattice. Additionally, Langmuir-Schaeffer films of gold nanoparticles on water surfaces are subjected to thermal and ultrasonic treatment in an attempt to correct defects in the films, which are then transferred to solid substrates for observation. Unfortunately, none of these approaches is able to reduce the defect concentration in a lattice, although thermal treatment and sonication of Langmuir-Schaeffer nanoparticle films are found to provide a controllable approach to depositing exact double layers of nanoparticles. / by Vladimir Tarasov. / S.B.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2008. / Includes bibliographical references (leaves 66-69). / Cancer immunotherapy attempts to stimulate the immune system to reject and destroy tumor cells. Despite the amount of ongoing intensive research to prevent cancer, tumor cells continue to evade immune responses. Currently, dendritic cell vaccines are in development, in which autologous antigen-loaded dendritic cells are injected back into the patient in order to generate an appropriate immune response. Improving upon this idea, members of the Irvine laboratory are in development of an injectable dendritic cell based formulation that gels in situ around the tumor site. In this way, immune cells (most notably T cells) can be recruited and become activated against specific tumor antigens, and (hopefully) kill tumor cells. Recent studies have shown the potential benefit of incorporation of cytokine interleukin-15 complexed with its soluble receptor interleukin-5R[alpha], which is discussed. Economic considerations are also discussed, including topics such as intellectual property, barriers to entry, initial markets and market drivers, and entry into the current supply chain considerations. A business strategy is outlined and evaluated. / by Andrew Song. / M.Eng.

Thesis: Sc. D., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2014. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 321-324). / Block copolymers (BCPs) have become a highly studied material for lithographic applications due to their ability to self-assemble into complex periodic patterns with feature resolutions ranging from a few to 100s nm. BCPs form a wide variety of patterns due the combination of their enthalpic interactions promoting immiscibility between the blocks and the bonding constraint through their chain topology. The morphologies formed can be tailored through a directed self-assembly (DSA) process using chemical or topographical templates to achieve a desired thin film pattern. This method combines the traditional top-down lithographic methods with the bottom-up self-assembly process to obtain greater control over long range order, the local morphology, and overall throughput of the patterns produced. This work looks at key modeling challenges in optimizing BCP DSA to achieve precision morphology control, reproducibility, and defect control. Modeling techniques based on field theoretic simulations are used to both characterize and predict the morphological behavior of a variety of BCPs under a variety of processing conditions including solvent annealing and DSA under topographical boundary conditions. These methods aid experimental studies by saving time in performing experiments over wide parameter spaces as well as elucidating information that may not be available by current experimental techniques. Both forward simulation approaches are studied where parameters are varied over a wide range with phase diagrams of potential morphologies characterized and inverse design approaches where given target patterns are taken as simulation input and required conditions to produce those patterns are outputted from the simulation for experimental testing. The studies ultimately help identify the key control parameters in BCP DSA and enable a vast array of possible utility in the field. / by Adam Floyd Hannon. / Sc. D.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1984. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Includes bibliographical references. / by Christine A. Wang. / Ph.D.

Thesis: S.B., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2017. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 35-36). / Redox-mediated separation systems offer the potential to efficiently desalinate water and to purify contaminated waste streams, among other health and environmental applications. A TCAQ-based polymer, unique for its two-electron redox reaction, was synthesized for use in redox-mediated separation systems, and its performance was quantified in low-concentration aqueous salt solutions. The polyvinyl ferrocene (PVF)//PTCAQ system displayed an ion adsorption capacity much higher than previously reported literature values for capacitive or redox deionization systems. / by Emily Thai. / S.B.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1990. / Includes bibliographical references (leaves 210-222). / by Jaeshin Cho. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2003. / Includes bibliographical references (p. 303-311). / Using first principles calculations the effect of electronic structure on the stability of positive electrode materials for lithium rechargeable batteries is investigated. The investigation focuses upon lithiated α-NaFeO₂ type 3d transition metal oxide structures. It is found that the ligand field stabilization energy (LFSE) is of particular importance in stabilizing the α-NaFeO₂ type layered structure with general formula Li[sub]x MO₂ (0 <[or equal to] x <[or equal to] 1 and M = Co, Fe, Mn, Ni, ...) at partial lithiation. The key quantity is found to be the difference in LFSE between the 3d metal ion in tetrahedral coordination and octahedral coordination in the cubic close packed (CCP) oxygen framework. If the change in LFSE is small, then the migration of 3d transition metal ions between tetrahedral and octahedral sites generally involves less variation in energy, and hence is easier. This facilitates diffusion of the 3d transition metal ions through the CCP oxygen framework and tends to destabilize the layered structure at partial lithiation. Layered lithium manganese oxide is given particular attention as a material that rapidly transforms to a spinel-like structure with electrochemical cycling. Focus is also placed upon layered lithium cobalt oxide as a material that remains stable in the layered structure with electrochemical cycling. The differing stability of these compounds in the layered structure is explained in terms of LFSE. Spin pairing energy (SPE) is also found to make an important contribution to the energetics of low spin transition metal oxides like lithium cobalt oxide. The influence of SPE on structural stability, as well as other aspects of transition metal electronic structure, are addressed as well. The importance of LFSE, and hence valence, on the stability of the layered structure recommends various doping strategies. In the case of lithium manganese oxide it is found that dopants which decrease the filling of the Mn e[sub]g orbitals stabilize Mn in octahedral coordination, and hence stabilize the layered structure. Dopants which produce this effect are identified as low charge fixed valence ions like Li+, A1³+, Mg²+, or elements with greater electronegativity than Mn³+ such as Ni²+, Co³+, or Cr³+. / by John Stuart Reed. / Ph.D.