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.

In der vorgelegten Arbeit werden sowohl effiziente als auch einfache Modifikationsansätze zur funktionalen Polymerumhüllung von Gibbsit-Plättchen präsentiert. Die plättchen-förmige Morphologie bleibt dabei nach der Polymerumhüllung erhalten. Im ersten Teil wird ein einfacher Ansatz zur Synthese von anisotropen, plättchen-förmigen Gibbsit-Polydopamin (G-PDA) Partikeln vorgestellt. Au NPs von kontrollierbarer Größe wurden auf der G-PDA Partikeloberfläche gebildet. Diese zeigten katalytische Aktivität zur Reduktion von 4-Nitrophenol und Rhodamin B (RhB) mittels Borhydrid. Die Partikel können durch ihre große, plättchen-förmige Kontaktfläche und der stark adhäsiven Eigenschaften der PDA Hülle einfach mittels Spin-Coating auf Siliziumsubstrate aufgebracht werden. Der so präparierte Nanokatalysator kann nun einfach wiederaufbereitet werden und zeigt hervorragende Wiederverwendbarkeit. Im zweiten Teil wurden anisotrope, hybride Kern-Schale Mikrogele mit wohldefinierter Struktur synthetisiert. Dabei bilden die Gibbsit Nanoplättchen den Kern und vernetztes, thermosensitives Poly(N-isopropylacylamid) die Hülle. Depolarisierte dynamische Lichtstreuung zeigte, dass die hybriden Mikrogele im kollabierten Zustand durch die plättchen-förmigen Kerne eine anisotrope Form annehmen. Der dritte Teil der Arbeit befasst sich mit der Herstellung von hochdispergierbaren, mesoporösen und stickstoffhaltighohle Kohlenstoff-Nanoplättchen. Diese neuartige Kohlenstoff-Nanostruktur wurde mittels sogenannter Silika-Nanocasting Technik unter Veswendung von hexagonalen Gibbsit-Templat und Dopamin als Kohlenstoffquelle synthetisiert. Solche hohlen Kohlenstoff-Nanostrukturen weisen exzellente, kolloidale Stabilität in wässrigen Medien vor und können direkt als Elektrodenmaterial für Superkondensatoren verwendet werden. Außerdem können sie in polyionischen Flüssigkeiten hohe Kapazitäten erzielen, wobei gleichzeitig eine hervorragende elektrochemische Stabilität gewährleistet wird. / In the present thesis, efficient and simple modification approaches have been developed to coat gibbsite platelets with a controllable thickness of functional polymer shell, which preserves the plate-like morphology after the polymer coating. In the first part, a facile approach has been presented for the synthesis of anisotropic plate-like gibbsite-polydopamine (G-PDA) particles. Au NPs with tunable size have been formed on the G-PDA particle surface, which show efficient catalytic activity for the reduction of 4-nitrophenol and Rodamine B (RhB) in the presence of borohydride. Such nanocatalysts can be easily deposited on silicon substrate by spin coating due to the large contact area of the plate-like G-PDA particles and the strong adhesive behavior of the PDA layer. The substrate-deposited nanocatalyst can be easily recycled, which shows excellent reusability. Secondly, anisotropic hybrid core-shell microgels with well-defined structures have been synthesized using gibbsite nanoplate as core and crosslinked thermosensitive poly(N-isopropylacrylamide) as shell. The analysis by depolarized dynamic light scattering shows that the hybrid microgels have an anisotropic shape in the collapsed state, caused by the anisotropy of the plate-like core. In the third part, highly dispersible mesoporous nitrogen-doped hollow carbon nanoplates have been synthesized as a new carbon nanostructure via silica nanocasting technique using dopamine as carbon precursor and hexagonal-shaped gibbsite as template. Such hollow carbon nanoplates show excellent colloidal stability in aqueous media and can be directly applied as electrode materials in supercapacitors, which offer high capacitance and excellent electrochemical stability when using poly(ionic liquid) nanoparticles as binder.

New water soluble, attainable to ATRP polymerization Cl-terminated poly(glycidol) macroinitiators were prepared by modification of (Omega)-hydroxyl group of poly(glycidol acetal) using 2-chloropropionyl chloride fallowed by selective acidic deprotection of acetal groups. The obtained macroinitiators of different molar masses were successfully employed in ATRP of NIPAM and 4VP to give well-defined stimuli sensitive block copolymers of targeted molar ratio of blocks. The results obtained from light scattering methods showed formation of stable aggregates upon stimuli (pH or temperature) by all the obtained polymers. Additionally, photocrosslinkable block copolymers of glycidol and NIPAM having incorporated moieties of chromophore (2-(dimethyl maleinimido)-N-ethyl-acryl amide) were prepared using macroinitiator technique and used to synthesis of temperature sensitive microgels. Conjunction points have been successfully formed by UV irradiation of polymer water solution above cloud point. The influence of such parameters like block ratio, block length, amount of chromophore, concentration, irradiation time, temperature and heating rate on the properties of obtained microgels was investigated. The obtained core-shell structures were stable under critical conditions and showed continuous volume phase separation process upon increase of temperature, fully reversible and reproducible (no hysteresis effect). Thus, the proposed method not only gave the opportunity to control size or swelling degree of microgels, but also diminished gradient in crosslinking density (random chromophore distribution in polymer backbone), improved colloid stability (poly(glycidol) shell) and completely eliminated additives (surfactants, initiators, stabilizers).

New water soluble, attainable to ATRP polymerization Cl-terminated poly(glycidol) macroinitiators were prepared by modification of (Omega)-hydroxyl group of poly(glycidol acetal) using 2-chloropropionyl chloride fallowed by selective acidic deprotection of acetal groups. The obtained macroinitiators of different molar masses were successfully employed in ATRP of NIPAM and 4VP to give well-defined stimuli sensitive block copolymers of targeted molar ratio of blocks. The results obtained from light scattering methods showed formation of stable aggregates upon stimuli (pH or temperature) by all the obtained polymers. Additionally, photocrosslinkable block copolymers of glycidol and NIPAM having incorporated moieties of chromophore (2-(dimethyl maleinimido)-N-ethyl-acryl amide) were prepared using macroinitiator technique and used to synthesis of temperature sensitive microgels. Conjunction points have been successfully formed by UV irradiation of polymer water solution above cloud point. The influence of such parameters like block ratio, block length, amount of chromophore, concentration, irradiation time, temperature and heating rate on the properties of obtained microgels was investigated. The obtained core-shell structures were stable under critical conditions and showed continuous volume phase separation process upon increase of temperature, fully reversible and reproducible (no hysteresis effect). Thus, the proposed method not only gave the opportunity to control size or swelling degree of microgels, but also diminished gradient in crosslinking density (random chromophore distribution in polymer backbone), improved colloid stability (poly(glycidol) shell) and completely eliminated additives (surfactants, initiators, stabilizers).