Anodization is a kind of method that can produce oxide layer in a large area and on flexible shaped metals. In some specific conditions, anodic oxide layers exhibit interesting nanopore/nanotube structures. In this work, focused ion beam patterning method is introduced to general 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 anodization, the guiding interpore distance is found to affect the new pores' locations and shapes. Two important elements, electrical field and mechanical stress, are discussed for the development of the guiding pores and the generation of new pores. Based on the proposed pore growth mechanism, novel patterns, non-spherical pores, and large patterns across the grain boundaries are successfully produced. The research on focused ion beam guided anodic titania nanotubes begins with surface polishing. The influence of four polishing conditions, as-received, chemically polished, mechanically polished, and electropolished samples, are investigated. A polished smooth sample provides a desired surface for focused ion beam guided anodization. Hexagonal guiding patterns with different interpore distances are created on Ti surface. Ordered nanotube arrays are produced, and the structure of the anodized guiding pattern is identified. / Master of Science

Over the past few decades, inorganic nanostructured materials have elicited a lot of interest due to their high surface-to-volume ratio and many size dependent properties which stem from their nanoscale dimensions. Owing to these distinct properties, they have found applications in widespread fields like catalysis, energy storage, electronics, and biotechnology. In the field of biotechnology, nanotubes and mesoporous materials are attractive vehicles for drug delivery because of their hollow and porous structures and facile surface functionalization. Their inner void can take up large amounts of drug as well as act as gates for the controlled release of drug. These hollow structures can also be used for confining biomolecules like proteins and peptides. The study on protein conformation in biocompatible materials is very important in materials sciences for the development of new and efficient biomaterials(sensors, drug delivery systems or planted devices). Titania(TiO2)has been widely explored for applications in photovoltaic cells, batteries, desalination, sensing, and photocatalysis, to name only a few. The work presented in this thesis focuses on titania based nanostructures for drug delivery and protein confinement. First part of the work focusses on synthesis and characterization of Fe-doped TiO2 nanotubes. Fe-doped TiO2 nanotubes were demonstrated as controlled drug delivery agents. In vitro cytotoxic effects of Fe-doped titania nanotubes were assessed by MTT assay by exposing Hela cell line to the nanotubes. Second part of the work focusses on synthesis and characterization of TiO2 nanotubes by two synthesis procedures, namely hydrothermal and sol-gel template synthesis. Myoglobin, a model globin protein was encapsulated in hydrothermally synthesized TiO 2 nanotubes(diameter 5 nm) and sol-gel template synthesized TiO2 nanotubes(diameter 200 nm). Effect of encapsulating myoglobin these nanotubes was studied. The electrochemical activity and structure of myoglobin were studied by cyclic voltammetry and circular dichroism respectively. Direct electron transfer was found to be enhanced upon confinement in 200 nm diameter nanotubes. No such enhancement was observed upon encapsulation in hydrothermally synthesized nanotubes. In addition to this, the thermal stability of myoglobin was found to be enhanced upon confinement inside 200 nm diameter TiO 2 nanotubes.