A new approach for the control of the size of particles fabricated using the Electrohydrodynamic Atomization (EHDA) method is being developed. In short, the EHDA process produces solution droplets in a controlled manner, and as the solvent evaporates from the surface of the droplets, polymeric particles are formed. By varying the voltage applied, the size of the droplets can be changed, and consequently, the size of the particles can also be controlled. By using both a nozzle electrode and a ring electrode placed axisymmetrically and slightly above the nozzle electrode, we are able to produce a Single Taylor Cone Single Jet for a wide range of voltages, contrary to just using a single nozzle electrode where the range of permissible voltage for the creation of the Single Taylor Cone Single Jet is usually very small. Phase Doppler Particle Analyzer (PDPA) test results have shown that the droplet size increases with increasing voltage applied. This trend is predicted by the electrohydrodynamic theory of the Single Taylor Cone Single Jet based on a perfect dielectric fluid model. Particles fabricated using different voltages do not show much change in the particles size, and this may be attributed to the solvent evaporation process. Nevertheless, these preliminary results do show that this method has the potential of providing us with a way of fine controlling the particles size using relatively simple method with trends predictable by existing theories. / Singapore-MIT Alliance (SMA)

Yes / A novel fluorescent monomer was synthesized to probe the state of CO2-responsive cross-linked polymeric particles. The fluorescent emission of this aminobromomaleimide-bearing monomer, being sensitive to protic environments, can provide information on the core hydrophilicity of the particles and therefore indicates the swollen state and size of the particles. The particles’ core, synthesized from DEAEMA (N,N-diethylaminoethyl methacrylate), is responsive to CO2 through protonation of the tertiary amines of DEAEMA. The response is reversible and the fluorescence emission can be recovered by simply bubbling nitrogen into the particle solution. Alternate purges of CO2 and N2 into the particles’ solution allow several ON/OFF fluorescence emission cycles and simultaneous particle swelling/shrinking cycles. / British Petroleum Company (BP), Engineering and Physical Sciences Research Council (EPSRC)

Gegenstand dieser Arbeit ist die Herstellung funktioneller Polymerpartikel und deren Nutzung für biomedizinische Applikationen. Die Anwendungsgebiete der resultierenden Hybridmaterialien reichen vom Einsatz als Kontrastmittel in bildgebenden Verfahren der medizinischen Diagnostik über die Verwendung als Antimikrobium bis hin zum Einsatz als „Werkzeug“ zur Zellisolierung und aktivierung. Dazu wurden kompakte Latexpartikel und sensitive, poröse Mikrogelpartikel mittels emulgatorfreier Heterophasenpolymerisation synthetisiert. Als funktionelles Monomer wurde Glycidylmethacrylat verwendet, über dessen reaktive Epoxygruppen anschließend weitere Moleküle angebunden werden können. Die Funktionalisierung der Polymerpartikel erfolgte einerseits mit anorganischen Nanopartikeln (dotierte Lanthanfluorid-Nanopartikel, Gold- und Silbernanopartikel) und andererseits mit Biomolekülen wie Nukleotiden und Antikörpern. Einige Verwendungsgebiete, wie die Stimulierung von Memory-T-Zellen mit Antikörper-Polymer-Konjugaten oder der Einsatz der Silberkomposite aufgrund ihrer antimikrobiellen Wirkung, wurden näher untersucht. / The aim of this work was the synthesis of functional polymeric particles and their use for biomedical purposes. The application areas of the resulting hybrid materials range from contrast agents in medical diagnostics and usage due to antimicrobial properties to “tools” for cell isolation and activation. Compact core-shell particles and porous microgel particles were prepared by surfactant-free heterophase polymerization in water. All particles contain glycidyl methacrylate whose epoxy groups are capable to bind other molecules covalently. On the one hand, polymeric particles were functionalized with inorganic nanoparticles (doped lanthanum fluoride nanoparticles, gold and silver nanopariticles) and on the other hand with biomolecules such as nucleotides and antibodies. Selected application fields like the stimulation of memory T-cells with polymer-antibody-conjugates or the use of the silver composites due to their antimicrobial activity were investigated in detail.

Gegenstand dieser Arbeit ist die Herstellung funktioneller Polymerpartikel und deren Nutzung für biomedizinische Applikationen. Die Anwendungsgebiete der resultierenden Hybridmaterialien reichen vom Einsatz als Kontrastmittel in bildgebenden Verfahren der medizinischen Diagnostik über die Verwendung als Antimikrobium bis hin zum Einsatz als „Werkzeug“ zur Zellisolierung und aktivierung. Dazu wurden kompakte Latexpartikel und sensitive, poröse Mikrogelpartikel mittels emulgatorfreier Heterophasenpolymerisation synthetisiert. Als funktionelles Monomer wurde Glycidylmethacrylat verwendet, über dessen reaktive Epoxygruppen anschließend weitere Moleküle angebunden werden können. Die Funktionalisierung der Polymerpartikel erfolgte einerseits mit anorganischen Nanopartikeln (dotierte Lanthanfluorid-Nanopartikel, Gold- und Silbernanopartikel) und andererseits mit Biomolekülen wie Nukleotiden und Antikörpern. Einige Verwendungsgebiete, wie die Stimulierung von Memory-T-Zellen mit Antikörper-Polymer-Konjugaten oder der Einsatz der Silberkomposite aufgrund ihrer antimikrobiellen Wirkung, wurden näher untersucht. / The aim of this work was the synthesis of functional polymeric particles and their use for biomedical purposes. The application areas of the resulting hybrid materials range from contrast agents in medical diagnostics and usage due to antimicrobial properties to “tools” for cell isolation and activation. Compact core-shell particles and porous microgel particles were prepared by surfactant-free heterophase polymerization in water. All particles contain glycidyl methacrylate whose epoxy groups are capable to bind other molecules covalently. On the one hand, polymeric particles were functionalized with inorganic nanoparticles (doped lanthanum fluoride nanoparticles, gold and silver nanopariticles) and on the other hand with biomolecules such as nucleotides and antibodies. Selected application fields like the stimulation of memory T-cells with polymer-antibody-conjugates or the use of the silver composites due to their antimicrobial activity were investigated in detail.

The research in this thesis considers novel innovative developments in established industrial processes that involve the use of recyclable polymeric particles as a partial replacement for aqueous media and chemicals. The application of the technology typically leads to water savings of over 80% and chemical savings of over 25%. These industrial processes may be characterised in that are considered inefficient and wasteful but nevertheless are considered economically vital. These diverse industries including laundry cleaning, leather manufacturing, textile garment processing, effluent treatment and metal beverage can manufacture. The outcomes of this research have made significant contributions to industrial best practice in such industries. In terms of academic research, the knowledge created in this thesis provides the basis for the application of CFD-DEM modelling to understand complex multi-phase and multi-component systems. In particular, the thesis advocates the application of the Free Surface Lattice Boltzmann Method for creating highly accurate simulations of multi-phase flow. In addition, the thesis offers opportunities for further research in novel plasma micro-reactors and their applications in diverse fields such as chemical synthesis, chemical engineering and biotechnology. The nature of the research is multi-disciplinary, and involved investigations across several fields including applied mathematics, biochemistry, chemistry, physics, and engineering. The projects also involved scale up from laboratory, pilot plant and full commercial scale production trials. Primary objectives were investigated through a series of six published patents. The three patents relating to the development of novel leather and textile processes were solely conceived and executed by the author. The patent related to the development of the plasma micro-reactor for ozone synthesis was conceived and executed jointly by the author and Professor Will Zimmerman (Sheffield University). The two patents related to the development of a novel metal cleaning and treatment process was conceived and executed jointly by the author and Dr. Robert Bird (Xeros Technology Group Limited).

Made available in DSpace on 2014-12-17T15:42:27Z (GMT). No. of bitstreams: 1 JulianaSN.pdf: 1926581 bytes, checksum: 39f0578ac55e6915852da779ae1734b5 (MD5) Previous issue date: 2007-10-18 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Magnetic particles are systems with potential use in drug delivery systems, ferrofluids, and effluent treatment. In many situations, such as in biomedical applications, it is necessary to cover magnetic particles with an organic material, as polymers. In this work, magnetic particles were obtained through covering magnetite particles with poly(methyl methacrylate‐comethacrylic acid) via miniemulsion polymerization process. The resultant materials were characterized X‐ray diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), zeta potential (��) measurements and vibrating sample magnetometry (VSM). XRD results showed magnetite as the predominant cristalline phase in all samples and that cristallites had nanometric dimensions. Thermogravimetric analysis revealed an increase in polymer thermal stability as a result of magnetite encapsulation. TGA results showed also that the encapsulation efficiency was directly related to nanoparticles s hidrofobicity degree. VSM measurements showed that magnetic polymeric particles were superparamagnetic, so that they may be potentially used for magnetic (bio)separation / Part?culas magn?ticas s?o sistemas com potencial de uso em libera??o controlada f?rmacos, ferrofluidos e tratamentos de efluentes. Em muitas situa??es, como em aplica??es biol?gicas, ? necess?rio revestir as part?culas magn?ticas com um material org?nico, como pol?meros. Neste trabalho, part?culas magn?ticas foram obtidas pelo revestimento de part?culas de magnetita por poli(metacrilato de metila‐co?cido metacr?lico) via processo de polimeriza??o em miniemuls?o. Os produtos obtidos foram caracterizados por difra??o de raios X (DRX), espectroscopia de absor??o no infravermelho por transformada de Fourier (FTIR), an?lise termogravim?trica (TG), medidas de potencial zeta (��) e magnetometria de amostra vibrante (MAV). Os resultados de DRX mostraram que a magnetita ? a fase cristalina dominante em todas as amostras, tendo seus cristalitos dimens?es nanom?tricas. A an?lise termogravim?trica revelou um aumento na estabilidade t?rmica das amostras com magnetita encapsulada e que a efici?ncia de encapsula??o foi diretamente relacionada ao grau de hidrofobiza??o das nanopart?culas. Medidas de magnetiza??o mostraram que as part?culas polim?ricas magn?ticas foram superparamagn?ticas, podendo ser satisfatoriamente utilizadas em processos de (bio)separa??o magn?tica