An opportunity to work with one of the established research groups at Leeds or Sheffield, in their laboratory.
A list of topics available will be given to students early in the session. Projects are generally based in one of the many nanoscience/technology-related research groups at Leeds or Sheffield University and involve a structured experimental investigation of a research or development nature. Some recent projects are illustrated below:
High resolution TEM imaging and image processing analysis of pore size distribution of activated carbons
Activated carbons are amorphous, nanoporous materials whose large surface area gives rise to excellent adsorption properties: they are used widely for filtering and de-odorising, including water purification and atmospheric pollution control. Clearly, the absorption properties of the materials are critically dependent on the nature and size of the pores.
The photograph (above left) shows a student using a high resolution field emission gun (FEG) transmission electron microscope (TEM) to view and analyse activated carbon samples. The FEGTEM has a minimum resolution of approximately 0.1 nm. The work involved sample preparation, imaging and image processing using Fourier Transform methods to determine the distribution of pore sizes, and to compare the performance of TEMs with different electron sources.
Magnetic properties of iron-complex biomolecules
Ferritin is a natural iron-carrying protein which contains typically 4,500 iron atoms in an approximately spherical 12nm diameter molecule. Iron dextran is an artificial analogue of ferritin which may be useful for treatment of iron-related disorders and, possibly, for treatment of certain cancers.
On the other hand, the magnetic properties of iron dextran suggest potential applications in high density magnetic storage. The project involved studies of the magnetic properties of both ferritin and iron dextran. The photograph shows a student preparing a sample for insertion into the muon spin resonance spectrometer at the Rutherford Appleton Laboratory.
Selective etching of titanium oxide surfaces for photonic band gap applications
The purpose of this project was to investigate the possibility of creating a photonic band gap structure from a periodic array of high refractive index titanium dioxide columns. The project involved synthesis of titanium dioxide by furnace oxidation, selective etching (reduction) to create structured surfaces, and surface analysis using scanning electron microscopy. The photograph shows a student loading a sample into the oxidation furnace.
Synthesis and characterisation of hydroxyapatite bio-implant coatings
Hydroxyapatite is a bio-compatible material which bonds very rapidly with bone tissue, and hence is useful as a coating layer for dental and other bio-implants. The photograph shows a student using a scanning electron microscope (SEM) to study the surface topology of a hydroxyapatite coating which he previously prepared using a sol-gel method. The project involved topological, microstructural and chemical characterisation to assess the adhesive properties of the coatings, as well as synthesis and deposition.
Protein folding and unfolding
The molecular force probe is an atomic force microscope designed to pull at large molecules on surfaces. A polymer in an aqueous environment is adsorbed on a surface. One end of the molecule attaches to an AFM tip by long-range intermolecular forces as the tip is brought closer to the surface. To pull the polymer from the surface, polymer-surface contacts have to be broken and the energy required to do this is measured. The MFP can do this with a sensitivity down to pN. It is difficult to pull at single molecules and often pulling events consist of tugging at molecules entangled with other molecules. Such entanglements have their own signature and the project here is to investigate pulling such entangled polymers.