Bachelor and Master Theses Topics

Mechanochemical synthesis and surface functionalization
In addition to classic solid-state reactions at high temperatures, solid-state reactions can also be brought about by mechanical energy using grinding in a high-energy ball mill. Impact, shear and frictional forces between the balls and the material being ground cause fractures in the material, causing it to be crushed down to the nanometer range. Reactions such as surface functionalization with organic phosphonic acids can take place on the newly created surfaces. In addition, metastable phases such as high-pressure or high-temperature modifications can be formed. As the thermal energy input in mechanochemical synthesis is low and no or only small quantities of solvents are required, this synthesis method is considered sustainable chemistry.
In their final theses, the students deal with the influence of reactive grinding on the structure and properties of oxidic phases, which, for example, enable the intercalation of lithium or sodium for energy storage. We compare the reactivity of systems synthesized via classical solid-state reactions and via a mechanochemical approach. Powder X-ray diffraction (XRD), infrared spectroscopy (IR), thermogravimetry (TG) and CHN analysis are used as characterization methods.
Current topics for theses are

  • Mechanochemical synthesis of mechanochemically activated energy storage materials
  • Mechanochemical reduction of metal oxides

Supervisors: Anna Michaely, Dr. Oliver Janka

Synthesis of superparamagnetic Fe3O4, MnFe2O4, and CoFe2O4 nanoparticles
Through chemical design of intrinsically self-healing materials, healing times and efficiency can be optimized while maintaining the desired material properties. The research project investigates novel nanocomposites in which reversible chemical interactions between inorganic nanoparticles and the polymer matrix induce the self-healing properties. The project focuses on the synthesis and functionalization of magnetizable iron oxide nanoparticles, as well as manganese and cobalt-containing iron mixed oxides, which are produced by thermal decomposition of organometallic precursors.
Supervisor: Kimia Moghaddari

New encapsulation materials for optical applications
Highly cross-linked polysiloxanes are promising materials for optoelectronic applications. Our group has developed a new material with sustainability aspects in mind, which makes it possible to produce LEDs with reduced or zero rare earth emissions. In the projects, these materials are to be further optimized by chemical synthesis so that the refractive index can be modified or the viscosity of the materials can be improved. In addition to synthetic and spectroscopic methods, the basics of viscoelastic and mechanical material characterization methods are taught.
Supervisor: Svenja Pohl

Continuous production of nanoparticles
The continuous production of submicrometer and nanoparticles finally makes it possible to produce these particles with high reproducibility and in high yields. Our working group has established the so-called microjet process for this purpose. The range of possible particles that can be produced using this process will now be investigated as part of final theses. Compounds with a low solubility product are particularly suitable for this purpose. We are not only interested in the range of different materials, but also in the microjet process itself. We can follow this in situ in the reactor using Raman spectroscopy.
Current topics for theses are

  • Production of polyoxometalate-based hybrid energy storage materials
  • Spectroscopic monitoring of crystal growth in a microjet reactor

Supervisor: Dr. Christina Odenwald