Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 33 for “"Nanophase"”.
-
Understanding and Optimizing Nanophase Separation Sintering
… and reduce the sintering time of the materials. Nanophase separation sintering (NPSS) was first explored by Dr. Mansoo Park. In this process, a mechanically alloyed powder experiences phase separation on the surface. This second phase promotes neck formation and rapid densification. By being a …
-
Nanophase separation in monodisperse rodcoil diblock polymers
… thin films we observe that the polymers ""nanophase"" separate into rod and coil-rich domains with dimensions of less than 10 nm, not common in typical coil-coil block copolymers. Highly periodic morphologies of rod and coil domains develop upon annealing and show a dependence on the …
-
Synthesis, Consolidation, and Mechanical Testing of Nanophase Metals
Indentation creep experiments were performed on nanocrystalline copper and palladium specimens and also on sinterforged Ti-48Al specimens. The copper and palladium specimens showed a higher creep rate than their microcrystalline counterparts, exhibiting creep even at room temperature. The …
-
Raman, Infrared, X-ray, and EELS Studies of Nanophase Titania
Sol-gel titania particles were investigated, primarily by optical techniques, by systematically varying synthesis, sample handling, and annealing variables. The material phases investigated were amorphous titania, anatase TiO2, and rutile TiO2. Annealing-induced phase transformations from amorphous …
-
Role of Nanophase Oxides in Short-Term Atmospheric Corrosion of Structural Steels
<p>Systematic studies on the development of nanophase iron oxides in the corrosion products of carbon and weathering steel were performed to understand the role of nanophase oxides in short-term atmospheric corrosion. Similarities and/or differences between short-term and long-term atmospheric …
-
Interaction of fluroquinolone antibiotics with nanophase metal oxide photocatalysts and soil minerals
… between fluoroquinolone antibiotics and nanophase metal oxides that contribute to their adsorption, transformation, and deactivation in engineered and natural aquatic systems. While the transformation of FQs under engineered treatment scenarios have been investigated, few studies have …
-
Nanophase Separation and Photochemical Reaction of Rodcoil Molecules, Reactive Liquid Crystal Molecules, and Binary Mixtures
"This work presents the synthesis and characterization of three related organic systems designed for self-assembly into ordered materials such as two dimensional objects and nanostructures. A family of reactive block molecules referred to as ""rodcoils"" was synthesized for the purpose of forming …
-
In-Situ Studies of Copper Nanoparticles Using a Novel Tandem Ultra-High Vacuum Particle Production Chamber Transmission Electron Microscope
Nanophase materials, a compaction of nano-particles, are arguably a new phase of matter whose high grain-boundary-to-volume ratio leads to new and enhanced material properties. Previously, these materials have been difficult to study because of their sensitivity to contaminating atmospheres. We …
-
Synthesis and Characterization of Multiblock Copolymers for Proton Exchange Membrane Fuel Cells (PEMFC)
Nanophase-separated hydrophilic-hydrophobic multiblock copolymers are promising proton exchange membrane (PEM) materials due to their ability to form various morphological structures which enhance transport. Four arylene chlorides monomers (2,5-Dichlorobenzophenone and its derivatives) were first …
-
Remote Sensing and Terramechanics Study of Mars using Orbital and Rover Data Sets
… cratered plains in Gusev Crater are dominated by nanophase ferric-oxide-rich dust covering weakly altered basaltic sands. Comparison of Mars Odyssey THEMIS-derived thermal inertia values with Mars Express OMEGA-derived spectral parameters shows that although the dust cover can be optically thick: …
-
Production and characterisation of nanoparticulate silicon photovoltaic devices
… milling, as well as commercially sourced nanophase intrinsic silicon powder. Results from microscopy revealed that the nanoparticles had formed clusters that were capable of transporting charge through the device. Results from the electrical characterisation show that the printed devices …
-
Incorporation of silica into baroplastic core-shell nanoparticles
Core-shell baroplastics are nanophase materials that exhibit pressure-induced flow at low temperatures and high pressures. Core-shell baroplastics used in this work are comprised of a low Tg poly(butyl acrylate) (PBA) core and a high Tg polystyrene (PS) shell. These novel polymer systems can be …
-
Low temperature processing of baroplastic core-shell nanoparticles and block copolymers
Baroplastics are nanophase polymeric materials comprised of two components that can miscibilize under pressure thereby facilitating flow. The possibility of processing these materials at low temperatures was the main focus of this work. Block copolymer baroplastics comprised of a low Tg and a high …
-
Multilayered supramolecular structures: Two-dimensional polymers and polar assemblies
… assemblies in solution cast bulk films with nanophase separation of the three chemically distinct segments. These assemblies stack spontaneously on solid substrates over macroscopic distances and form self-assembled surfaces. Moreover, the substrate seems to guide the stacking direction of …
-
Mechanical and Electrical Characterization of Carbon Fiber/Bucky Paper/Zinc Oxide Hybrid Composites
… properties could be transmitted to CFRPs when a nanophase of ZnO is embedded within CFRPs. In lieu of ZnO nanorods, Bucky paper comprising mat of multiwall-carbon nanotubes (MWCNTs) could be sandwiched in-between laminae to construct a functionally graded composite with elevated electrical and …
-
Electric Field Manipulation of Gold Nanorods: Characterization of Far-Field Alignment and Spatial Positioning Through Optical Response Imaging Techniques
… techniques that ensure good dispersion of the nanophase. While good dispersion is critical, the next step is to move toward `micro'structures that may be able to take specific advantage of the nanoscale physical interactions. With respect to metallic nanoparticle polymer composites, current …
-
Synthesis and Characterization of Hydrophilic-Hydrophobic Disulfonated Poly(Arylene Ether Sulfone)-Decafluoro Biphenyl Based Poly(Arylene Ether) Multiblock Copolymers for Proton Exchange Membranes (PEMs)
… solvent cast into tough membranes, which had nanophase separated hydrophilic and hydrophobic regions. The performance and structure-property relationships of these materials were studied and compared to random copolymer systems. NMR results supported that the multiblock sequence had been …
-
Synthesis and Characterization of Hydrophobic-Hydrophilic Multiblock Copolymers for Proton Exchange Membrane Applications
… ionic domains at low hydration levels. Nanophase separated hydrophilic-hydrophobic block copolymer ionomers are believed to be desirable for this purpose Three series of hydrophobic/hydrophillic, partially fluorinated/sulfonated multiblock copolymers were synthesized and characterized in …
-
Design of bulk nanocrystalline tungsten alloys via nano-phase separation sintering
… grain growth during a thermal cycle, so nanophase separation sintering is thus naturally appropriate to the production of fine-grained bulk materials. Sintered compacts achieved through nano-phase separation sintering display 10~30 times smaller grain sizes at comparable densities than …
-
Sintesi e caratterizzazione di nanocompositi aerogel altamente porosi per applicazioni catalitiche
… of nanocomposite aerogels, made out of an active nanophase dispersed in a highly porous amorphous silica matrix. These nanocomposites have unique properties which mainly depend on the composition, size and distribution of the nanoparticles and on the morphology and porosity of the matrix. Highly …
Page 1 of 2