Dimensionally constrained material systems are at the forefront of current materials research because of their novel and often enhanced physical, chemical and biological properties. The dimensionality effects are pervasive through different classes of materials including ceramics, metals and polymers. Often times dimensionality effects are manifested as internal structure variations in...
For bone regeneration, there is need for biodegradable, synthetic scaffolds that direct the formation of <em>de novo</em> mineralized tissue. Orthopaedic implants additionally require mechanical function. The work described herein attempts to address both of these needs. The general strategy involves integrating molecularly designed tissue engineering scaffolds with porous metallic foams...
The work presented in this dissertation focuses on ceramic anode materials for solid oxide fuel cells (SOFCs). The primary goal was to characterize the anode and relate the electrochemical behavior to the microstructure. The anode that was most extensively studied in this work was a composite of Gd0.10Ce0.90O1.95 (GDC) and...
The kinetics of nanoscale Cu-rich precipitates of multicomponent concentrated steels has been investigated utilizing primarily APT and supplemented with a synchrotron radiation experiment, first-principles calculations, Thermo-Calc study, and CTEM (at the longest aging time). Results on mechanical properties and microstructure at a greater length scale are also presented. The studied...
This dissertation demonstrates how self-assembly can direct nanoscale ordering and optimize electronic properties of organic semiconductors, as well as organic-inorganic hybrids. In excitonic solar cells, controlling the ordering and interfaces between electron-transporting (n-type) and hole-transporting (p-type) domains is crucial. In addressing this challenge, hybrid nanostructures were designed by mineralization of...
A novel cryogenic variable temperature UHV STM has been constructed and utilized to investigate the dynamical behavior of isolated organic molecules covalently bound to silicon surfaces.
The microscope can be operated from 8-300 K, and exhibits extremely low drift rates. A new design has been implemented for the rails (used...
Two main topics are addressed in this dissertation: (1) adhesion in hydrogels; (2) interfacial interactions between model glassy polymers. A self-assembly technique for the formation of hydrogels from acrylic triblock copolymer solutions was developed, based on vapor phase solvent exchange. Structure formation in the gels was characterized by small angle...
Metal nanoparticles in polymeric matrices are of particular scientific interest due to their useful ability to self-assemble into complex nanocomposites. Recent examples involve using ultrathin diblock copolymers coupled with metal nanoparticles in the fabrication of novel electronic, magnetic and photonic devices. As this ordering process takes place far from equilibrium...
The current trend of ceramic nanotechnology has motivated an ever-increasing need to achieve exquisite control over size, shape, and spatial confinement for functional oxide architectures, in an equivalent manner demonstrated for semiconductors. However, the unique nature of ceramics has posed major challenges for most traditional nanofabrication technologies, putting the development...
The use of composites is increasing as they afford scientists and engineers the ability to combine the advantageous properties of each constituent phase, e.g. metal ductility and ceramic stiffness. With respect to materials design, biomimetics is garnering increasing attention due to the complex, yet efficient, natural microstructures. One such biomimetic,...