This project was focused on the generation of porous and nanotubular anodic films on titanium and Ti-6wt.%Al alloy, and investigation of the key factors responsible for a transition between porous and nanotubular morphologies. Advanced analytical techniques were employed for characterisation of the anodic films, in particular scanning and transmission electron microscopies, including analytical transmission electron microscopy, Raman spectroscopy, nuclear reaction analysis, Rutherford backscattering spectroscopy and atomic force microscopy. Preparation of electron transparent sections for analysis by analytical transmission electron microscopy was undertaken using the focused ion beam technique. Initially, the influence of a post-anodizing rinsing treatment, using various media, on the morphology, structure and composition of anodic films generated on titanium in 0.2 M ammonium fluoride in glycerol, containing 0 and 5 vol.% added water, was investigated. Porous anodic films were formed in an electrolyte without added water followed by rinsing with ethanol. It was revealed that the oxide-rich nanotubes are embedded in a fluoride-rich matrix, with fluoride-rich material being more extensive and oxide-rich nanotubes being thinner-walled for the anodic films generated in the electrolyte with no added water followed by rinsing with ethanol compared with those for the films formed with added water to the electrolyte and rinsed similarly. However, post-anodizing rinsing of the former films transforms the porous morphology of the films to a tubular one. The contents of titanium and fluorine were reduced in the case of anodic films with the nanotubular morphology. It was suggested that dissolution of the fluoride-rich matrix occurs during rinsing of the specimens with water, leading to the transition from porous to nanotubular morphologies and subsequent loss of titanium and fluorine. Further work was undertaken to study the effect of ageing in deionised water on the morphology, structure and composition of the anodic films. It was revealed that loss of titanium and fluorine is greater for the films generated in the electrolyte with no added water followed by rinsing with water and ethanol and ageing compared with that for the films formed in the electrolyte with 5 vol.% added water followed by rinsing with water and ethanol and ageing. Finally, the anodic films generated on the Ti-6wt.%Al alloy were investigated. Porous anodic films were formed in the electrolyte without added water followed by rinsing with ethanol whereas the films treated with water disclosed nanotubular morphology. Porous anodic films contained greater amount of fluorine than nanotubular ones. Compositional analysis revealed an increased amount of fluorine for the anodic films generated on the alloy compared with those for the films formed on titanium under all investigated conditions. The difference in film compositions may be related to the difference in composition of the substrates used for anodizing, in particular, to the presence of aluminium as alloying element in the Ti-6wt.%Al alloy.

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.