This thesis is concerned with tackling three major challenges of melamine formaldehyde (MF) microcapsules for delivering of core materials: reducing the formaldehyde content in the formulation, modulate the mechanical properties and reducing the leakage of the core material through the microcapsules. Thus, to reduce the formaldehyde content in the microcapsules, a low formaldehyde to melamine (F/M) molar ratio (0.20-0.49) compared to the conventional literature formulations (2.30-5.50) was used to produce the MF microcapsules in this study. It was found that there is a relatively small window of F/M molar ratio between 0.20 and 0.49 in which the wall thickness and nominal rupture stress of the microcapsules can be modulated significantly. Above 0.49 increases in F/M molar ratios only increase these properties marginally. Furthermore, to reduce the leakage of the microcapsules, organic/inorganic double shell composite microcapsules with MF/copolymer as the inner shell, and ripened CaCO\(_3\) nanoparticles as the outer shell were produced. A ~20 fold reduction in leakage was observed between the double shell composite microcapsules and the MF microcapsules by the end of 24 hours, and it was also found that the mechanical properties of these double shell composite microcapsules are dominated by the CaCO\(_3\) nanoparticles outer wall. Finally, calcium shellac matrix containing MF microcapsules and unripened CaCO\(_3\) nanoparticulate microcapsules (complex capsules) were also produced to reduce the leakage. A ~37 fold leakage reduction between calcium shellac matrix containing MF microcapsules and MF microcapsules alone by the end of 20 days was observed, and a ~14 fold reduction was found between calcium shellac containing unripened CaCO3 nanoparticulate microcapsules and the unripened CaCO\(_3\) nanoparticulate microcapsules alone.

The aim of this thesis is the investigation of the use of a RAFT agent developed by the company Lubrizol, BMDPT (Butyl-2-methyl-2-[(dodecylsulfanylthiocarbonyl) sulfanyl] propionate) produced in tonnes scale to make amphiphilic block copolymers in ester solvent (butyl acetate and methoxypropyl acetate). For this purpose, a broad range of monomers including acrylate, methacrylate and styrenic containing tertiary amine were polymerised and used as pigment dispersants. As the starting point, the reactivity of n-butyl acrylate (n-BA) and di(methyl)aminopropyl acrylate (DMAEA) monomer followed by the synthesis of acrylate diblock copolymers in acetate solvents (butyl acetate and methoxypropyl acetate) are investigated. The second chapter is focused on the methacrylate polymerisation which is a large body of work of this thesis. The poor reactivity of the trithiocarbonate RAFT agent towards methacrylate monomer was already published few times. Consequently, the kinetic studies of butyl methacrylate (BMA) and di(methyl)amino ethyl methacrylate (DMAEMA) was investigated in batch mode. Subsequently, a new synthetic route is explored to reach a well-controlled diblock copolymers. In the third chapter, a novel class of amphiphilic diblock copolymer containing acrylate and a mixture of styrene and maleic anhydride is explored. Then, the functionalisation of polymer backbone is carried out by using an amine in order to insert an anchoring group for pigment affinity. Finally, the efficiency of all the diblock copolymers on carbon black pigment dispersion is reported. A combination of different techniques such as dynamic light scattering (DLS), transmission electronic microscopy (TEM) and thermogravimetric analysis (TGA) are used to investigate the interaction between the polymer and the pigment.

This thesis investigates the degradation and release of a fluorescent dye from biodegradable microparticles. Particular attention is given to determining the effect of polymeric properties on the subsequent microparticle degradation and release rate. Chapter 1 reviews the current polymerisation techniques for the synthesis of polyesters and introduces the synthetic procedures and degradability currently attainable for biodegradable microparticles. The concept of ‘smart’ release technology is introduced and the potential for using biodegradable ‘smart’ particles for enhanced agricultural formulations is explored. In Chapter 2, the ring-opening polymerisation (ROP) of a variety of polyesters is demonstrated, including an investigative study on the ROP of poly(3-hydroxybutyrate) (PHB) using magnesium 2,6-di-tert-butyl-4-methylphenoxide (Mg(BHT)2(THF)2). The polyesters are used to prepare microparticles via a single oil-in-water solvent evaporation technique, a range of formulation parameters are studied to enable optimisation of the subsequent particle size and stability. Chapter 3 investigates the encapsulation of a model fluorescent dye into poly(L-lactide) (PLLA) microparticles and the subsequent PLLA particle degradation and dye release under simulated environmental conditions is reported. Chapter 4 describes the degradation and release of 3-bromo-4-(butylamino)-2,5-dihydro-1H- pyrrole-2,5-dione (ABM) from a range of polyester microparticles, investigating the effect of polymer properties (e.g., molecular weight, crystallinity, etc.) on the particle degradation and release rate. In Chapter 5, the incorporation of a stimulus responsive polymer using optimised particle synthesis and degradation conditions (detailed in Chapter 2 and 3) is investigated. The successful tuneable microparticle degradation and release is described by incorporation of a light-responsive poly(nitrobenzyl malic acid) (PNO2BnMA) into homopolymer blends of PLLA microparticles. Chapter 6 explores the synthesis of degradable poly(vinyl acetate) (PVAc) microparticles by the incorporation of 2-methylene-1,3-dioxepane (MDO) degradable ester linkages into the polymer backbone via free radical ring-opening polymerisation (rROP) and post- polymerisation microparticle synthesis (using the optimised solvent evaporation technique detailed in Chapter 2). The successful encapsulation of ABM into P(MDO-co-VAc) microparticles is reported and compared to encapsulation into PVAc microparticles. In Chapter 7, the synthesis of poly(ω-pentadecalactone) (PPDL) microparticles using the optimised single oil-in-water emulsion technique (Chapter 2) is reported. Investigation into the synthesis and degradation of films prepared from random copolymers of PPDL and poly(ɛ- caprolactone) (PCL) is described. An attempt at polymerisation-induced self-assembly (PISA) using block copolymers of PPDL and poly(ɛ-decalactone) (PeDL) is demonstrated. In chapter 8, a general summary of Chapters 2-7 is presented and key findings and conclusions highlighted. Chapter 9 provides the experimental methods used throughout this thesis and Chapter 10 provides supporting degradation studies for Chapter 3 and 4.

The focus of the work presented here is the theoretical description of the photodissociation of molecular systems possessing low-lying singlet 3s/\(\pi\)σ* states that are quasi-bound with respect to an N-H bond. Model Hamiltonians are developed for and subsequently used in quantum dynamics simulations of the photo-induced dynamics of the molecules ammonia, 3-pyrroline, pyrrole, and aniline. The origin to the barrier to dissociation in ammonia's first excited state is identified and the effect of vibronic coupling of this state to a number of higher-lying states on the dissociation dynamics of the molecule is assessed. A conformer-resolved study of the dynamics of 3-pyrroline following excitation into its first two excited states is performed, and the first two bands in its electronic spectrum are calculated and analysed. The first band in the electronic spectrum of pyrrole is calculated, its vibrational structure assigned and the role played by intensity borrowing in its formation analysed. The dynamics of aniline following excitation to its first to singlet \(\pi\)\(\pi\)* are studied. Two previously neglected 3p Rydberg states are found to play important roles in aniline's excited state dynamics. The first two bands in aniline's electronic absorption spectrum are calculated, and the role played by the Hertzberg-Teller effect in the first band is analysed

The effect of processing and formulation parameters on the resulting oil-in-water, emulsion microstructure has been studied for a recently developed process; rotating membrane emulsification. A broad range of surfactant and particle dispersions were explored to reveal the key drivers that determine the final droplet size produced. The aim of the study was to understand initial droplet generation and therefore emulsion stability, whilst a significant element in emulsification studies, is not considered here. By furthering the understanding of the processing mechanisms involved, this enabled development of theoretical models to estimate droplet size and extent of coalescence from first principles. In addition, the implications of process scale-up were studied. From this work, the very first design procedure for rotating membrane emulsification was derived and proposed. The final emulsion microstructure is heavily dependent on the coupled interaction between the fluid flow behaviour of the two phases and interfacial phenomena. Careful selection of process parameters based on sufficient characterisation of properties such as interfacial tension and viscosity, can avoid the occurrence of droplet coalescence or dispersed phase jetting. These can have a detrimental effect on producing a carefully controlled microstructure on a repeatable basis. Of particular importance is the rate of surfactant adsorption at the oil/water interface. A unique approach of dispersing non-ionic, high HLB surfactants such as Tween 20 and Brij 97 within the oil phase has been found to significantly reduce droplet size. This discovery allows the process to be highly competitive with a rotor-stator high shear mixer and an ultrasonic probe at a fraction of the energy consumption. Pilot-scale operation of rotating membrane emulsification provided important insight into how one might design and therefore implement the process for an industrial purpose. It is proposed here that a suitable scale-up parameter would be the membrane surface velocity.

Molten salts have been widely used as thermal energy storage (TES) materials as they offer favourable specifications which enable them to be employed in TES applications. Finding a cost-effective method to enhance the energy storage capability of molten salts has caught the attention of many researchers. It was reported that by adding a small amount of nanoparticles, a major enhancement of the specific heat capacity was observed in molten salts. Though different studies argued that the enhancement was not found in other thermal storage materials, the observation of the enhancement was continuously reported. This work studied the thermal properties of molten salt based nanosuspensions synthesized with a novel method modified based on other studies. Molecular dynamics (MD) simulations were employed to study the thermodynamic properties of the nanosuspension systems. By the analysis of the effect on the internal energy of the nanosuspensions I draft general conclusions and explain why molten salt have this specific heat enhancement while other materials (e.g. water) does not. I use MD simulation to support, for the first time, a theory that can explain the apparently contradictory behaviour of the experimental data. Moreover, the main impact factor affecting the enhancement was investigated and discussed.

Within the past decades, extensive research has been focusing on developing electroluminescent technologies (OLED and LEC). Especially, a lot of effort has been dedicated to the search a efficient phosphorescent materials with highly tuneable emission maxima bearing l a te transition metal atoms. Emitters such as cyclometalated idirium complexes have been proven to be very successful in this regards exhibiting colours from blue to red and being successfully applied in electroluminescent technologies. However, in order to decrease the manufacturing cost of these technologies, a single-centre white emitting material is highly desirable. In this context, this work investigates a new family of complexes bearing three different bidentate ligands known as tris-heteroleptic complexes to develop an emitter with a broad emission profile that would result in a white colour. Eighteen new tris-heteroleptic complexes with unprecedented ligand configurations have been synthesised by mixing different kind of ligand such as phenylpyridines (ppy), phenylpyrazo les (ppz) and phenylimidazoles (pim). This resulted in significant emission broadening with FWHM values up to nearly 6000 em- 1.

The work presented in this thesis investigates the use of new luminescent lanthanide complexes, both free and bound to the surface of gold nanoparticles, for protein labelling. Lanthanide complexes were shown to maintain their luminescence properties when conjugated to proteins and one complex also demonstrated participation in Förster resonance energy transfer when conjugated to a protein in an appropriate system. Furthermore, it was found that bovine serum albumin can act as a vehicle to transport luminescent lanthanide complexes into two human cell lines. Lanthanide complexes were then used to coat 13 nm gold nanoparticles for protein labelling within cells. The aim was to find a peptide sequence to preferentially bind to gold nanoparticles which could be expressed as part of a protein of interest, acting as a binding site within the cell. The interaction of peptides with gold nanoparticles was examined using several methods and, of the sequences tested, CCPGCC was found to have the highest affinity for the nanoparticles. This peptide was expressed in HeLa cells as part of green fluorescent protein. Co-localisation of the nanoparticles with the protein in cells could not be established through fluorescence microscopy, however, cell lysis revealed green fluorescence protein associated with nanoparticle aggregate.

The objectives of this thesis are to explore, design, fabricate and implement the use of advanced micro-engineered platforms to be exploited as versatile, novel device technologies. An increasing number of technologies require the fabrication of conductive structures on a broad range of scales and large areas. Here, we introduce advanced yet simple electrohydrodynamic lithography for patterning conductive polymers directly on a substrate with high-fidelity. We illustrate the generality of this robust, low-cost method by structuring thin films via electric-field-induced instabilities, yielding well-defined conductive structures with a broad range of feature sizes. We show the feasibility of the polypyrrole-based structures for field-effect transistors, which might herald a route towards submicron device applications. We also demonstrate a miniaturised platform technology for timely, sensitive and rapid point-of-care diagnostics of disease-indicative biomarkers. Our micro-engineered device technology (MEDTech) is based on reproducible electrohydrodynamically fabricated platforms for surface enhanced Raman scattering enabling tuneable, high-throughput nanostructures yielding high-signal enhancements. These, integrated within a microfluidic-chip provide cost-effective, portable devices for detection of miniscule biomarker concentrations from biofluids, offering clinical tests that are simple, rapid and minimally invasive. Using MEDTech to analyse clinical blood-plasma, we deliver a prognostic tool for long-term outcomes, in the hospital or at the point-of-care.

This thesis seeks to augment the understanding of gelled micro-particulate suspensions known as sheared/fluid gels, by investigating the use of dairy proteins (whey, WPI) as the gelling material. The research used a microstructural approach to probe the underlying design principles governing the formation, and subsequent material properties of WPI microgel systems. The work initially focused on preparing suspensions through both thermal and cold-set approaches. By controlling two key processing parameters: shear and gelling rate, it was shown that a range of suspension properties could be produced. In both cases, it was demonstrated that structural characteristics could be controlled, for tailored rheologies. The shear technology was then applied to a more complex system of oil and whey protein, resulting in the formation of microcapsules; as the WPI gelled around the oil droplets in a core-shell model. Again, controllable structural properties were obtained, however, the lipophilic core provided a reservoir for potential delivery. This multi-functional formulation was then investigated under gastro-intestinal conditions, highlighting controllable release as a function of the type of oil used in production. Therefore, the potential use of WPI/WPI-oil micro-particles have been presented as a multi-functional composite for both structure and delivery within food ingredients.