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This thesis describes the growth of bismuth oxide (Bi2O3) and multiferroic bismuth ferrite (BiFeO3) films via chemical vapour deposition (CVD). The synthesis of a range of bismuth(III) β-diketonate complexes was carried out via a ligand-exchange reaction between [Bi(N(SiMe3)2)3] and the respective free ligand, and crystal structures of [Bi(dbm)3]2 and [Bi(acac)3] are reported. The decomposition of these complexes was studied via DSC-TGA to assess their potential as single-source precursors to Bi2O3, and the mass transport characteristics of the volatile complexes [Bi(mmp)3], [Bi(thd)3] and [Bi(OtBu)3] were studied. Bi2O3 films were grown via the LPCVD reaction of the single-source precursor [Bi(OtBu)3]; the crystalline phase (and band-gap) of the resultant films depended strongly upon the reactor conditions. Films were tested for photo-oxidation of water under UV-light, revealing high activities comparable to those of TiO2 films described previously. [Bi(dbm)3]2 was utilised as a single-source precursor to β-Bi2O3 films via AACVD, together with the growth of Pt(0) films using H2PtCl6.6H2O as a precursor. Pt-nanoparticle Bi2O3 films were grown via a ‘one-pot’ AACVD reaction of both precursors; composite Pt-Bi2O3 films were able to evolve hydrogen via the photo-reduction of water, a property not observed for films containing either Pt or Bi2O3 alone. BiFeO3 films were grown via a multi-source LPCVD reaction between [Fe(acac)3], [Bi(OtBu)3] and air, as well as via the dual-source reaction of [Bi(OtBu)3] and [Fe(OtBu)3]2 without oxidising gas, and, furthermore, via the single-source precursor [{Cp(CO)2Fe}BiCl2] using AACVD. Magnetometry revealed low temperature ferromagnetism and spin-glass behaviour, characteristic of larger particle sizes. Ferroelectric measurements revealed low polarisation but nevertheless indicated films were multiferroic at room temperature. A selection of these films were tested for photo-oxidation of water under visible-light; films displayed high photoactivities with rates in excess of those from optimised TiO2 films measured under UV-light, highlighting the potential of BiFeO3 films as strong visible-light active photocatalysts.

The thesis concerns a comprehensive study to develop and assess the predictive capabilities of a lumping model for the kinetics of complex reaction mixtures containing a large number of reacting components. Two types of lumping models were developed to reduce the number of reaction kinetics, namely a discrete and a continuum lumping model. These models were applied on three different problems. In the first case study, a continuum model was developed for a mixture of n-paraffins (waxes) produced from the Fischer-Tropsch process; the paraffins range from C5 to C70 and undergoing catalytic hydrocracking. The model was run with two types of the reactant-type distribution functions to describe the yield of products from the isomerisation and cracking reactions. The model was used to study the effect of the operating conditions on the model parameters and the yield composition. Experimental data were used to optimise the model parameters. The optimal parameters were used to predict the product distribution of n-paraffins hydrocracking and their conversion. The new in this case study was used the carbon number as label in the continuum lumping model and to study how the effect of D(k) on the yield distribution. Good agreements have been obtained when running the model with D(k) employed a gamma function but it needs more time to solve the model than when employing a power law relation for D(k). In the second case study, both primary and secondary reaction kinetics of the pyrolysis of lignin were investigated by using the discrete lumping methodology. Two mathematical models were developed which consider the product as three lumps whilst the lignin was assumed to be an additional lump. The model’s results were validated against experimental data. In addition, a continuum lumping model was developed for the cracking of the tar to obtain lighter components. The novelty in this case study is to develop a kinetic model including primary and secondary reaction kinetics for the pyrolysis of lignin in a fluid bed pyrolyser and to study how the continuum lumping model for tar can be linked to the discrete lumping model. In the third case study, a model based on the continuum lumping approach was proposed to predict the molecular weight distribution of polymers during batch polymerisation. The result obtained from a continuum model was assessed, at this stage, only qualitatively; nevertheless, by analysing the weight distribution and the average of such distribution, conclusions were reached to assess the predictive capability of the lumping methodology. It is the first time that the continuum model with a yield distribution function is used to predict the molecular weight distribution of the polymerisation at various times.

This thesis is based on a study of the behaviour of the multiple burner systems. The influence of number of burners, their separation and degree of swirl on the interaction of multiple gaseous turbulent diffusion flames, for different configurations chosen, has been investigated. A single flame has been studied as a reference flame to provide information for the comparison with multiple systems. The temperature and concentration profiles within the flames have been determined using thermocouples and a semi-continuous gas sampling system in conjunction with a gas chromatograph. Three orthoganol mean velocity components in the annular air stream of a single isothermal swirling jet have been measured using a hot wire anemometer and by the application of a four point measurement technique developed within the department. Multiple flame systems were found to be less stable against blow-off compared to single flames and the blow-off limit shifted towards the fuel rich region as the swirl was reduced. At low swirl levels and minimum separation the centre flames were lifted off the burner rim and were frequently blown-off.

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