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 26 for “"Porous alumina"”.
-
Model for porous alumina template formation
Anodized alumina templates have emerged as an important material system for the low cost fabrication of semiconductor and metal nanostructure arrays. This material system utilizes natural self-organization for the creation of periodic arrays of nanoscale structures. The underlying principle is that …
-
Commercial applications of nanostructures created with ordered porous alumina
… drive from microfabrication to nanofabrication, porous alumina templates may play a key role in technological evolution. Under the right processing conditions, ordered pores can grow in anodic aluminum oxide, which is a high strength, thermally and electrically insulating material. There are many …
-
Development and research of porous alumina xerogel membranes for electrospray propulsion applications
… section specifically focusses on cast alumina xerogels (porosities less than 90% typically around 40-50%) and briefly investigates a manufacturing procedure. The main problem facing the performance of these extractor membranes is the consistency of their geometry and porosity given the …
-
Phenomenological study of Au and Pt nanowires grown in porous alumina scaffolds
Porous anodic aluminum oxide, commonly known as AAO, has been widely used as a scaffold to synthesize nanowires and nanotubes. The porous alumina structure can be obtained from a simple electrochemical oxidation process, applying a positive voltage to an aluminum film placed in an electrolyte, and …
-
Novel Preparation of Porous Alumina using Ice Particles as Pore-Forming Agents
Porous ceramics have successfully been used in a wide variety of highly advanced applications. Current routes to porous ceramics are limited in the types of porosity they can create and no one process is flexible enough to create any desired structure. This study introduces the use of ice particles …
-
Investigation of porous alumina as a self-assembled diffractive element to facilitate light trapping in thin film silicon solar cells
… and cost-effective fabrication method of using porous alumina as a self-assembled textured photonic crystal. Porous alumina is an attractive material because under certain anodization conditions, the pores form an ordered array. The ordered pore structure on the surface can serve as a …
-
Electrical characterization of thin film nanostructure templates
… into device operation. Ni is deposited into porous alumina templates to create Ni nanostructures.
-
Fabrication, assembly, and electrical characterisation of gold nanowire
… and characterisation of gold nanowires. Porous alumina membranes have been electrochemically fabricated as templates for the deposition of gold nanowires. They consist of a thick oxide membrane, shown to be perforated by a high density array of isolated cylindrical pores, with a narrow …
-
Controlling ceramic porosity using carboxylate-alumoxane nanoparticles
The formation of carboxylate substituted alumina nanoparticles, [Al(O) x(OH)y(O2CR)z]n, is an environmentally benign and inexpensive process. The alumoxane nanoparticles are synthesized from the mineral boehmite with carboxylic acids. The physical characteristics of carboxylate-alumoxanes, such as …
-
Templated self-assembly of nanoporous alumina : pore formation and ordering mechanisms, methodologies, and applications
Porous anodic aluminum oxide (AAO), also known as porous alumina, is a self-ordered nanostructured material well-suited for use in electronic, magnetic, optical and biological applications due to its small pore size (4-200nm) and spacing (10-500nm). Under slightly acidic conditions, both oxidation …
-
Synthesis and Characterization of Nanostructures in Porous Anodic Aluminum Oxide Templates
… nanowires, nanotubes, and core-shell structures. Porous alumina membranes were employed as templates and metal nanostructures were synthesized in the templates by electrodeposition. By using lithography techniques, controlled patterned nanostructures were also fabricated on alumina templates. The …
-
Nanopore/Nanotube Pattern Formation through Focused Ion Beam Guided Anodization
… aiming to make highly ordered anodic porous alumina and titania nanotubes. Focused ion beam guided porous anodic alumina is carried out by pre-designing hexagonal and square guiding patterns with different interpore distances on well electropolished Al foil before anodization. After …
-
Sol-gel deposition of oxide-ion conducting thin films ; and, Liquid precursors to hafnium and tantalum carbides
… (Me). Copper-doped films were spincoated onto nonporous quartz substrates and pyrolyzed. These were initally defect-free, but became agglomerated on heating at higher temperatures. The use of a number of different additive compounds was tried, but did not greatly improve the behavior of the films …
-
Fabrication of porous ceramics and composites by a novel freeze casting process
Porous ceramics have been widely used in many fields. Among the fabrication techniques for porous ceramic, freeze casting has recently attracted much attention as being a versatile, low cost and environmental friendly process. In this study, alumina and Al\(_2\)O\(_3\)-ZrO\(_2\) were utilized as …
-
Optical Characterization of Electrochemically Self-Assembled Compound Semiconductor Nanowires
… by electrochemical deposition of Zn inside nanoporous alumina films containing regimented arrays of 10nm, 25nm and 50 nm diameter pores, followed by room temperature chemical oxidization. Fluorescence spectroscopy shows different characteristics associated with different sample diameter. The 50 …
-
The modification of activated carbon cloth by alumina deposition
The impregnation of mesoporous carbon cloth with alumina has been studied. The most successful method of impregnation resulted from preparation of the alumina phase by a sol/gel route. This method involves a boehmite intermediate, and the heating environment for the thermal transition of boehmite …
-
The Effect Of Stationary UV Excitation On The Optical Behavior Of Electrochemically Self-Assembled Semiconductor Nanowires
… material in electrochemically self-assembled porous alumina templates. Our studies are based on the optical behavioral changes in CdS, ZnO, ZnSe and CdSe quantum wires of 50-, 25- and 10-nm diameters. We use a set of generalized Bloch equations to solve the interband polarization function of …
-
Fatigue crack propagation in functionally graded materials
… experiments and finite element (FE) analysis. Alumina-epoxy composites with an interpenetrating-network structure and tailored spatial variation in composition were produced via a multi-step infiltration technique. Compressed polyurethane foam was infiltrated with alumina slip. After foam …
-
The role of nanostructured targets in Laser-Produced Plasmas for Nuclear Astrophysics studies
… nanowires grown by electrodeposition into a porous alumina matrix, obtained on a thick aluminium substrate. These materials were developed with different length, diameter, metal and deposition technique in order to maximize absorption in the visible and IR wavelengths. Various diagnostics …
-
Hierarchical Semiconductor, Metal and Hybrid Nanostructures and the Study of their Light-matter Interactions
… deposition of the metal into the channels of a porous alumina structure grown perpendicularly from the curved surface of a micrometer scale aluminum wire. The functionality of the cloak was demonstrated by partial cloaking in the visible range (540 nm).
Page 1 of 2