Liquid Air Energy Storage (LAES) aims to large scale operations a~d-:_has caught the attention due to the advantages of high energy density, a highly competitive capital cost, no geographical constraints and environmental friendliness. However, the situation is getting more challenging due to its disappointed performance in the current configuration. This thesis focuses increase the system performance of the LAES technology, particularly through developing novel thermodynamic cycles for an increased use of the thermal energy and system optimization strategies. The improvements to the LAES mainly aim at two points: increasing power output by using compression heat and rising the liquification rate through external cold sources. To effectively use the heat, three integrated LAES systems with the Organic Rankine Cycle (ORC) are proposed, termed LAES-ORC-VCRC system, LAES-ORC-ARC system and LAES-ORC system respectively according to different cooling methods. External cold sources, such as Liquefied Natural Gas (LNG), can be used to enhance air liquefication, and hence two integrated LAES systems, termed the LAES-LNG and the LAES-LNG-CS, are investigated and optimized.

Calcium phosphates (CaPs) have been used extensively as bone replacement materials, substrates for drug release and transfection agents because of their non-cytotoxic nature and chemical similarity to the mineral component of human bone. However, biomolecule attachment to CaPs usually rely upon adsorption, which can lead to inconsistent coverage and variable release, and the fate of CaPs upon cellular internalisation is not fully understood. The difficulty in tracking the particles can be related to the visual similarity to granulation within the cells. This thesis sought to functionalise the surface of CaP particles to enable the engraftment of biomolecules onto the particle surface and the formation of a cross-linked matrix. The engraftment of a thiol-reactive fluorescent dye gave visual confirmation that molecules can be bound to the surface and enabled silicon-substituted hydroxyapatite (SiHA) particle tracking within MC3T3 cells. Volume and size distribution analysis suggested that internalised particles larger than 1μm, but not encapsulated within lysosomes, correlated with observations of cell death. The method was expanded for other CaPs and demonstrated through engraftment of a novel antimicrobial peptide, which was shown to be more effective at preventing biofilm formation than surface adsorbed peptide, and the fabrication of a new organic/inorganic composite.

Metallic nanoparticles (MNPs) are attracting increasing interest for many applications in photonics, ranging from optoelectronic devices to bioimaging and biosensing. An advantage of these systems is that their optical properties, governed by their localised surface plasmon resonance, are widely tunable via the nanoparticle shape and size, which can be controlled via e.g. colloid synthesis. In that context, it is important to develop accurate experimental methods able to correlate the size and shape of an individual single MNP, measured with nanometric precision, with its individual optical properties. In this thesis, three different MNP systems, namely i) commercially-available Ag nanocubes of 75 nm edge; ii) Ag tetrahedra, bi-tetrahedra and decahedra in the 25 - 50 nm size range which was fabricated in-house using a plasmon-mediated photochemistry method; iii) Ag nanodimers was fabricated in-house via controlled self-assembly of polymer linkers onto commercial nominally spherical Ag nanoparticles of 40 nm diameter. Beyond fabrication, a substantial part of the work reported in this thesis describes the experimental protocol for correlative optical and transmission electron microscopy, which was developed and optimised, comprising reproducible deposition of these silver nanoparticles onto TEM grids, their optical characterisation via polarisation-resolved high-resolution dark-field and extinction micro-spectroscopy, and subsequent high-resolution TEM of the same particle. As proof-of-concept, the same Ag nanocubes of 75 nm edge were characterised optically in different dielectric environments, using solvents of different refractive index n; specifically, anisole (n=1.52), water (n=1.33), and air (n=1). The MNP scattering and extinction cross-section was determined in absolute units using an in-house developed quantitative measurement protocol, and the results are compared with numerical simulations using the measured geometry. These studies pave the way toward an in depth understanding of the relationship between geometrical and optical properties of MNPs of non-trivial shapes, which in turn have the potential to be exploited in innovative bioimaging and biosensing platforms.

Freeze drying is a widely-used dehydration technique in food and pharmaceutical industry, involves water crystallisation (freezing) and ice sublimation during the process. The purpose of the study is to enable the initial concentration of solutions that are used in freezing and freeze drying processes to be increased, as an approach to reduce the energy consumption of the process. Spontaneous crystallisation from both sucrose solutions and coffee solutions was studied by DSC, XRD and cryo-SEM, and results showed that increasing solid concentration (up to 70%) significantly delayed the water crystallisation, shown as lower crystallisation temperature and less or even no ice crystal formation. A method was developed to induce water crystallisation by adding already formed ice seeds to water, which allowed the study of ice crystal growth rate at controllable conditions. The method combined the use of a temperature controlled stage and an optical microscope, and the effects of solid concentration (up to 60%), temperature, viscosity, solute type, and air bubbles on crystal growth were investigated. Freeze drying high concentration sucrose (up to 60%) showed significant volume expansion (collapse), and methods to reduce the collapse were tried by modifying the formulation (adding high molecular weight gum Arabic) or freeze drying cycles (reducing heating rate between primary and secondary drying). Results showed that the up to 30% concentration of sucrose solution can be dried without volume expansion with modified freeze drying process.

Within the framework of this techno-economic assessment, the possible contribution of the platform technology Thermo-Catalytic Reforming (TCR®) to reduce CO2 emissions, save resources, and solve waste problems was evaluated. The selection of the feedstocks included samples of sewage sludge, woody biomass, algae, organic fraction of municipal solid waste, leather residues, peat, lignite, and selected mixtures thereof. These feedstocks were processed in a lab-scale TCR plant with a capacity of 2 kg/h and converted into oil, gas, and carbonisates. It is targeted to utilize these products as substitutes for fossil resources for energetic and material usage. For each feedstock, optimum process parameters, correlations regarding feedstock and product composition and yields, and measures to optimize the technology, were identified. The experimental results were used as a basis for the economic evaluation. To identify promising value chains, the levelized costs/levelized revenues approach was adopted for multi-product processes. State of the art technologies and the products thereof were the benchmark. By linking the results of the technical and economic evaluation, the optimum utilization pathways for the processed feedstocks, related products, and potentials to increase the competitiveness of the technology were identified.

This thesis deals with the development of a microfibrillated cellulose based product from Imerys, made from wood pulp using a stirred media mill. Applications for microfibrillated cellulose are explored. Parameters for the generation of microfibrillated cellulose in the stirred media mill are tested for the formulation of a product with the greatest increase to the strength of paper. Models used in milling are applied to the milling of cellulose and calcium carbonate. Based on the models, ways of finding the most energy efficient process for future new materials and mills are explored. Improvements to models are suggested for both the general case of particle size reduction and the specific case of cellulose milling. A study of the energy transfer mechanisms in the mill and how they relate to the kinetic energy of the media is performed using Positron Emission Particle Tracking. The relationships between the distributions of media kinetic energy thus found and the products of milling are analysed. Modifications to the mill are made based upon these findings and tested. An environmental life-cycle assessment is performed of the product, which tests the overall environmental impacts of including microfibrillated cellulose as a strength aid in paper.

Plenoptic imaging is an exciting research field since, by introducing a microlens array into the optical train of a traditional camera, directional information about incoming light rays is stored on the sensor. Whereas traditional cameras discard this information, plenoptic imaging takes advantage of this increase in angular resolution to provide a method of snapshot 3D capture. With a plenoptic dataset, the ability to extend depth of field and refocus digitally, post-acquisition, is of key benefit to bioluminescence tomography. Due to low light imaging conditions, large apertures are required to capture enough signal from a bioluminescence imaging subject; this causes a shallow depth of field, and when mirrors are introduced into the system to increase subject coverage, managing the system focal planes can be hard. In order to investigate the best uses of plenoptic imaging for biomedical research, a simulation platform was created to allow efficient, flexible, cost effective exploration of system design and algorithm development. This simulation platform was utilised in designing a plenoptic multi-view system, which is applicable to bioluminescence tomography. A correction to the bioluminescence free space model is made which facilitates quantitative imaging. Finally, a plenoptic tomography system is created which allows snapshot, multi-view 3D capture.

For the past two decades, organic light emitting diodes (OLEDs) have been the subject of intense research in the realm of display and lighting applications. Recently, thermally activated delayed fluorescence (TADF) has shown great potential in further advancing OLED technology. In order to achieve TADF, synthesis of acceptor and donor compounds has been undertaken to achieve exciplex formation. Little is currently known about exciplex formation and emission, so systematic structural variations have been performed on MCP and DPBI in order to gain fundamental knowledge. Compound analyses were performed in both the solid and solution state. In the case of MCP derivatives, demonstration of their ability to act as an acceptor is possible, alongside an appropriate choice of donor molecule. Reducing the extent ofconjugation in derivatives of DPBI, did not result in an increase in triplet energy. Consequently, to eliminate possible conformers, steric blocking was introduced in an attempt to increase the triplet energy. In the case of the ME-DPBI derivative it was shown possible to formulate a device showing 2.5% external quantum efficiency while emitting at ~450 nm which is a true blue colour.

Increasing plastic consumption has created an alerting problem with waste disposal of the mixed waste plastics once the recyclable fractions have been recovered. The percentage sent to landfill of the generated mixed plastic waste amounts to one third of the total. Liquid fuel recovery from mixed plastic waste is possible using pyrolysis as a tertiary recycling process. The focus of this study was to obtain useful liquid product recovered from the pyrolysis of a variety of commercial mixed plastic waste utilising a pilot scale fluidised bed reactor of 1kg/hr processing capacity. The influence of residence time (1.78 to 2.74s), feedstock variation and reaction temperature (500 – 550oC) were investigated to optimise the quality of the wax products. Characterisation of the mixed plastic feedstocks through TGA, DSC and FTIR analysis was carried out to lay the foundation of the pyrolysis conditions. Understanding the fuel quality and product distribution was essential in assessing the key properties such as melting point and viscosity in the optimisation process. Key findings of the research concluded that increasing residence time has the strongest effect on reducing the melting point (up to 14oC) of the liquid product across all studied feedstocks although the magnitude of the effect greatly depends upon the initial feedstock composition. Changes is the average melting point correspond to a shift in the average carbon number distribution of the product. Feedstock and process parameters variability were also found to greatly affect the final product quality resulting in a versatile product composition as well as the product yields that varied between 27 and 60% w.t.

Saturated fat has a good potential for improving emulsion stability and products texture. However in the past ten years, food industry has intended to reduce its amount to prevent its impact on heart diseases. Therefore a better understanding of fat crystallisation has been studied to design the final properties of fat systems by changing the formulation and process of crystallisation. Fat crystallisation occurs in several stages like nucleation, crystal growth and fat network formation. Adding emulsifiers or waxes has demonstrated the possibility to change the process of crystallisation by promoting primary or secondary nucleation as a function of additive concentration. The head group size of emulsifiers has also exhibited an influence on fat crystallisation by promoting secondary nucleation with glycerol or primary heterogeneous nucleation with sorbitol. Furthermore waxes differing by their single or multi-component nature, have induced secondary and primary nucleation respectively. The process of crystallisation has been changed by applying different cooling rates and shear rates; increasing the cooling rate increased the number of nucleation sites and shear could enhance the interactions between fat and emulsifiers. Finally formulation and process have displayed the design of the final texture and allowed a reduction in saturated fat of 50 % while keeping the same network strength.