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M. Czakler:
"Verknüpfte Metallnanopartikel für neue Hybridmaterialien";
Supervisor: U. Schubert, M.-A. Néouze; Institut für Materialchemie, 2011; final examination: 2011-01-10.

In this thesis the synthesis of functionalized metal nanoparticles for their use as building blocks in new hybrid materials is presented. Earlier work has been done with metal oxide nanoparticles, which were functionalized with different ligands. These ligands contain an anchor group, connecting the ligand to the nanoparticle surface and stabilizing it, and a terminal functional group. The functional group can be either a haloalkyl or imidazole. The functionalized nanoparticles are then linked by a click-chemistry-like reaction of the haloalkyl with the imidazole, forming an imidazolium moiety. This nanoparticles network, connected by ionic linker, forms an inorganic-organic hybrid material.
The resulting materials are built by highly ordered nanoparticles, resulting in new properties of great interest. This thesis works on stepping from the metal oxide nanoparticles to metal nanoparticles. Adapting the process to metal nanoparticles requires new synthesis methods for the nanoparticles as well as new ligands. The anchoring groups of the ligands for metal oxide nanoparticles were silanes or phosphonates. These anchoring groups are to be substituted by anchoring groups for metal nanoparticles, like thiols or amines.
This work is divided into two main parts. The first part describes attempts to functionalize gold nanoparticles. The second part is dedicated to cobalt nanoparticles. Using cobalt nanoparticles, the magnetism depends on the length of the ligand between the nanoparticles. Modifying this ligand by altering the chain length of the alkyl units, could lead to modified magnetism or optical properties, making this hybrid material designable.

Project Head Marie-Alexandra Néouze:
Ionische Verknüpfung von Nanopartikeln