Qualifications

BACHELOR-, MASTER THESES AND PRACTICAL COURSES

• Synthesis of highly porous silica xerogels as thermal insulation material

Topics Advanced and Master Theses | Supervised by M.Sc. Kai Müller

In order to reduce energy consumption in Germany and worldwide, effective materials for thermal insulation must be developed. With their help, the required heating energy can be significantly reduced.

One of the most promising materials is silica aerogels, which are produced based on the sol-gel process. These highly porous gels have extremely low thermal conductivities, but are only used to a limited extent due to the currently still high production costs and low stability. Silica xerogels, on the other hand, show improved stability and significantly lower manufacturing costs, although the thermal conductivity of the material increases.

Within the framework of a master's thesis, the properties of the xerogels are to be optimised in the direction of lower thermal conductivities with the same stability.

• Synthesis of sustainable carbon-silica composites for wastewater treatment

Topics Bachelor, Advanced and Master Theses / Supervised by M.Sc. Bettina Lilli

The discharge of contaminated wastewater into natural resources can cause harm to humans and the environment. The removal of pollutants such as persistent pharmaceuticals or pesticides from water is therefore crucial for the protection of the environment. Since the early 2000s, a large number of scientific studies have shown that conventional wastewater treatment plants do not remove pharmaceuticals adequately, if at all. One possible solution is to introduce a fourth adsorptive treatment stage in wastewater treatment plants. In addition to activated carbons, which are already known for their high adsorption capacity, carbon-silica composites, which contain both porous carbon and silica, are available as possible adsorption materials.

In the context of green chemistry, the sustainable synthesis of such adsorbents for the removal of pollutants from water is becoming increasingly important. Agricultural residues in particular are playing an increasingly important role. In this theme, carbon-silica composites will be prepared from the agricultural residue rice husks via various synthesis steps. The variation of different parameters will be investigated.

• Synthesis of sustainable foam glass panels for exhaust gas purification

 Bachelor thesis, advanced thesis, master thesis / Supervised by M.Sc. Tim Jähnichen

In Germany there are approx. 11 million stoves, which must fulfil limit values for emissions and dust according to BImSchV. To achieve these limits, catalytically active porous ceramics are currently used. However, these are produced in energetically expensive, non-sustainable processes. A cost-effective and sustainable alternative is the synthesis of catalytically active foam glass sheets. Here, waste glass (old car glass) is foamed at elevated temperatures with the help of a harmless foaming agent, resulting in open-cell glass panels.
Within the scope of qualification work, the synthesis parameters are to be varied in order to increase the porosity and pore size of the foam bodies produced and to obtain an open-cell structure. In addition, various active catalysts will be applied to the material. The samples will be analysed primarily with mercury intrusion, SEM-EDX, XRD and light microscopy.

• Porous Glasses as Transdermal Drug Delivery Systems (TDDS)

Topics Bachelor, Advanced and Master Theses / Supervised by M.Sc. Theresa Paul

Porous glass is to be studied as a potential transdermal delivery systems for various drugs. Due to their tunable pore size and volume as well as their large surface area, porous glasses present advantageous and novel properties for these applications.
Student works are possible in our research group, where material science aspects are studied. Possible student works include functionalization of the glass surface, modification of the pore structure and the development as well as improvement of methods to obtain ultra-thin and flexible glass membranes. (BA, MA, Vertiefer possible)
Students interested in the construction and automation of a model plant-system to stretch form porous glasses are also welcome to apply. Basic knowledge or interest in LabView, coding and engineering are preferred. (MA, Vertiefer students only)
It is further possible to do student works with our research partners in the pharmacological department of the University of Leipzig (Rudolf-Boehm-Institute for pharmacology and toxicology). Thereby drug loading and release kinetics are investigated via HPLC mass spectrometry. Furthermore, biocompatibility, adhesion to skin and toxic effects of the innovative drug carrier are examined. (Vertiefer, MA or teaching students)
Student works are possible in English and German.

• Development of porous, high-temperature stable CeO₂ supports for sustainable CH₄ production from greenhouse gases

Topics regarding Bachelor, Advanced and Master Thesis / Supervised by M.Sc. Tim Jähnichen

Due to depleting oil and natural gas reserves sustainable production of valuable fuels such as synthetic natural gas from CO and CO₂ (SEG) or bioethanol from sugar- or starch-containing plants is becoming increasingly important. If CO/CO₂ from the atmosphere or renewable resources is used for sustainable SEG synthesis, greenhouse gases are reduced and global warming is counteracted. Low-cost supported nickel-based catalysts possess high selectivity and activity in this hydrogenation reaction. For these catalysts, it has been shown that the support (Al₂O₃, CeO₂, ZrO₂, etc.) not only determines the textural properties and dispersion of the active phase, but also plays a key role in CO₂ activation. Ceria has excellent redox properties (Ce³⁺/Ce⁴⁺ redox couple) and also exhibits high oxygen storage capacity. Accordingly, ceria supports possess a large amount of oxygen vacancies with intermediate basicity compared to other support materials, which promote CO₂ activation dissociation and metal-support interaction.

The following tasks will be pursued in the context of preparing an open-pore ceria support material from phase-separated glasses for SEG synthesis from atmospheres CO/CO₂:

• Preparation and characterization of homogeneous Na₂O-B₂O₃-CeO₂ glasses.
• Generation of uniform phase separation to adjust porosity.
• Obtaining a comprehensive understanding of phase transformation during heat treatment and extraction
• CO/CO₂ adsorption studies concerning the influence of pore texture as well as phase composition