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The work detailed in this thesis concerns polymers synthesised by R.F. inductively coupled plasmas excited in fluorine containing monomer vapours. The structure and bonding in a series of polymers prepared from per-fluoroaromatic monomers by plasma polymerization was investigated by ESCA. The composition and structural features of these films were compared and contrasted with each other and with plasma polymers derived from the same parent compounds with lower degrees of fluorination. Critical emission spectra, ~260-600nm, from these plasmas were recorded and a correlation made between certain species fluorescing in the gas phase and functional groups within the polymer. An association hcis also been made between the peaks at ~280 and ~510nm in the optical emission spectrum. Difluorocarbene is responsible for the peak at ~280nm but the peak at 510nm has an unknown origin. The effect of copolymerizing a fluoroaronatic compound with a second component on polymer composition has been examined, where the comonomer has ranged from an inert gas to an organic hydrocarbon analogue. Copolymerizaticn resulted in a stabilisation of the rearrangement mechanisms normally associated with the plasma polymerization of a perfluoroaromatic compound; CF=CF(_n) and CF(_2) groups were greatly reduced in intensity in the ccpolymer. The binding energy of the CF-CF(_n) peak indicated that the component peak was, in fact, due to CF-CF(_aromatic) i.e. copolymerization had also resulted in a greater retention of the aromatic nature of the parent fluorocotpound. Polymers were also prepared by irradiating the monomer vapour with wavelengths >130nm. Perfluorobenzene could not be polymerized with UV irradiation of wavelengths greater than 200nm, but could however be polymerized with wavelengths below 200nm. This produced a polymer whose composition, as determined by ESCA, was very similar to the composition of plasma polymers derived from the same monomer indicating that the mechanisms involved in both polymerizations are similar. Vibrationally excited ground state perfluorobenzene is thought to be involved in the reaction pathway.

In this Thesis the processes of electron emission from cathode electrodes are studied theoretically, and the applicability of these mechanisms to the non refractory cathodes that can be used to sustain thermal arcs was examined. Apparatus that was used to generate and manipulate thermal arcs along rail electrodes is described in this thesis. Techniques for driving arcs over polished sample electrodes with magnetic or aerodynamic forces are outlined. Scanning electron microscopy was used to study emission site formation on highly polished electrodes with a natural 2.5 nm oxide layer. Theoretical maximum electron current densities that can be extracted by the arc were calculated and these were used, in conjunction with information from the experimental work, to make estimates of the lifetime of emission spots that are seen on the cathode electrodes of thermal arc devices. The lifetime was found to be dependent on the arc velocity over a range of velocity values from 3 to 80 ms(^-1). The lifetime measured ranged from 2.4 µs to 0.024 µs. Experiments on arcs driven at a constant velocity using a combination of aerodynamic and magnetic forces showed that the formation of emission spots was independent of die applied external magnetic field. The presence of artificially grown copper (11) oxide layers, 50 nm and 100 nm thick, were found to influence the lifetime. The effect of the oxide layer was predicted using a simple model accounting for the change of resistance that such an oxide layer would be expected to cause. Additional experiments showed that the resistance of the arc was independent of the oxide layer thickness, as predicted by the model.

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