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A new series of dendronised monomers of different generations possessing different chemical structures has been designed, synthesised and characterised. Dendrons were initially synthesised in a stepwise manner from t-butanol, CDI and 1- [N, N-bis(2-hydroxyethyl)amino]-2-propanol (HEAP) and were then coupled to norbomene derivatives for the provision of dendronised monomers, in particular, mono- and di-substituted first generation and di-substituted second generation polycarbonate dendronised monomers containing t-butyl terminal groups have been synthesised. Two di-substituted second generation polyurethane dendronised monomers containing t-butyl and 4-heptyl terminal groups were also successfully synthesised. Dendronised polymers have been synthesised from the NMR scale ring opening metathesis polymerisations of mono- and di-substituted first generation polycarbonate dendronised monomers along with a di-substituted second generation polycarbonate dendronised monomer, using varying ratios of monomer to initiator. It was found that the polymerisations were well-defined and that di-block copolymer products could be obtained due to the living nature of the systems. Molecular modelling studies have been performed using the CAChe® 3.2 program on the di-substituted second generation polycarbonate dendronised monomer and on a dendronised polymer up to a degree of polymerisation of 16. It was found that low DP oligomers of the second generation polycarbonate dendronised monomer had an approximately spherical shape, which tended towards cylindrical as the DP increased. The polymer at a DP of 16 had dimensions of approximately 10 nm diameter by 4 nm thickness. AFM images were also obtained using a scanning probe microscope MultiMode™ Nanoscope IV. The structures were found to be pancake shaped with dimensions of between 30-50 nm diameter and 3-6 nm thickness, which was approximately a factor of 3 greater than the dimensions calculated by molecular modelling. This discrepancy in size between the modelling studies and the AFM results is thought to arise from the effect that structure-solvent and structure-substrate interactions have on the overall conformation of the dendronised polymer when imaging by AFM.

Let Dk be the ring of integers of a finite extension of Q(_p), and let h ɛ Q≥(_0) be in its value group. This thesis considers the space of locally analytic functions of order h on Ok with values in Cp-. that is, functions that are defined on each disc of radius by a convergent power series. A necessary and sufficient condition for a sequence of polynomials, with coefficient in C(_p), to be orthogonal in this space is given, generalising a result of Amice [1] . This condition is used to prove that a particular sequence of polynomials defined in Schneider Teitelbaum [19] is not orthogonal.

Research to investigate advanced diffusion coatings for improved oxidation and hot corrosion resistance was conducted. The aim was to build on the performance of the standard aluminide on the nickel-base super alloy IN738LC. The main emphasis of this investigation was to examine the effects of adding small quantities of yttrium to the coating as well as to produce a platinum-modified aluminide diffusion coating which is accepted as the best industrial standard for diffusion aluminides at present. A pack diffusion process was used to produce the coatings in this current study. A standard aluminide coating was modified with a small YCI3 (0.5 Wt.%) addition to the pack, producing an aluminising-yttrising pack. In the platinum-modified altuninide coating process, a sample was coated with several microns of platinum using a sputtering technique prior to the aluminising process. The pack used in this platinum modified aluminide process was a standard aluminising pack. The performance of these modified coatings during oxidation and high temperature corrosion was evaluated. Promising results were obtained, which demonstrated that both platinum and yttrium modified aluminide coatings had beneficial effects on the oxidation performance of the coatings compared to the standard aluminide coating. However, they were found to work in different ways, to improve resistance to oxidation and hot corrosion resistance. The platinum modified aluminide extends the later stage of the coating life by reduces the amount of spall, whist yttrium modified aluminide reducing the amount of spall in the early stage of the coating life and increases the critical oxide thickness before the onset of spallation. From these results, the production of a combined platinum-yttrium modified aluminide coating would be expected to show improved oxidation and hot corrosion resistance throughout the life of the coating. This could be another direction for future work.

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