Diploma tasks
Solvothermal production of a piezomagnetic and piezoelectric composite coating on implant materials
Bachelor or Diploma
Defective joints and large fragmented bone segments have long been replaced with scaffolds and implants. The implants come very close to the morphological, structural and mechanical properties of the biological tissue to be replaced. However, it is not yet guaranteed that the implants will also transfer bioelectrical signals, which would be necessary to stimulate certain physiological functions such as the control of bone growth and which is naturally inherent to biological bone material. Research is still being carried out into surface structuring or implant coatings that can support or even accelerate the osseointegration (healing and reformatting of the bone) of foreign materials. The remodeling of bone tissue to maintain its functionality is a dynamic process that is controlled very individually depending on changing mechanical requirements. It is generally assumed that elastic deformations experienced by bone tissue are transposed into electrical surface charges and influence, among other things, the interactions of ions and salts in the environment and thus protein adhesion and the associated cell behavior. The content of the work is the development of a multiferroic composite coating using piezomagnetic and piezoelectric ceramics. The work includes the planning and studies on solvothermal synthesis reactions for piezomagnetic cobalt ferrate on titanium and its combination as a composite coating with piezoelectric barium titanate (BaTiO3). For this purpose, different solution approaches are pursued by means of solvothermal synthesis and varied depending on the reaction parameters (e.g. reagents, solution concentration, temperature, pressure...).
Contact: Dr. Ute Bergmann
Biomimetic coating of metal surfaces to prevent ice adhesion
Small or large evidence
There are organisms that can tolerate partial freezing of their body fluids and survive at temperatures well below the freezing point of water. In some cases, such organisms can form a symbiosis with bacteria that control the crystallization behaviour of liquids, or they can reduce the freezing point of their body fluids within certain limits by means of antifreeze proteins. With increasing understanding of the mechanism of action of these proteins or surface membranes, new approaches can be found for solving technical problems. For example, the direct use of antifreeze proteins as additives in technical refrigerants and the use of ice-nucleating bacteria for the production of artificial snow are well known. A biomimetic adaptation of the described active principle as a surface treatment of metals appears promising for the prevention of ice and frost formation. The starting point of the work is to biomimetically functionalize metallic surfaces using methods of colloid chemistry. The topic presented provides insights into material science and chemical investigation methods. This project is based on cryological investigations of the icing behaviour of silanized metal surfaces. Subsequently, the ice adsorption behavior of seemingly suitable coatings on differently pretreated aluminum substrates will be analyzed and compared with the coating parameters determined by scanning electron microscopy and atomic force microscopy.
Contact: Dr. Ute Bergmann