Controlled formation of cobalt-particles in nanoscaled self-assembled structures

Abstract

In this thesis, the aim was the defined synthesis of Cobalt-nanoparticles by help of nanoscaled, structuring stabilizers. This goal was reached using two different kinds of nano-template. In the first part of the present work, low-molecular surfactants were taken and special systems were optimized, until we could control size, order and dispersion of the particles. As last consequence, we found a way of producing a long-time stable Co-powder, which was tested to be ferromagnetic at least for 1 year at ambient atmosphere. This is an aggregate, which is formed at temperatures between 170 ° C and 180 ° C containing TDS-protected Co-nanoparticles, which can be redispersed from this powder even 1 year after synthesis, while the magnetic properties stay unchanged. The second part of this work was dealing with block copolymer micelles as structure and stability source. The mechanism of Co(II)-uptake into block copolymer micelles of the type PS-b-P2VP could be cleared. The most successful way to generate Co-metal within polymeric micelles was the thermal decomposition of Co2(CO)8 within the micelles. In der vorliegenden Arbeit war das Ziel, die definierte Synthese von Cobalt-Nanopartikeln mit Hilfe von nanostrukturierten, strukturgebenden Stabilisatoren zu bewerkstelligen. Es konnte ein Co-Partikelpulver hergestellt werden, das über einen Zeitraum von 1 Jahr hinweg an der Luft seine ferromagnetischen Eigenschaften behielt. Der zweite Teil dieser Arbeit handelt über PS-b-P2VP-Mizellen als Strukturelement bei der Herstellung von Co-Nanoteilchen. Die erfolgreichste Route ist die Verwendung der thermischen Zersetzung von Co2(CO)8 innerhalb des Mizellkerns.