Cellular ceramics with three levels of hierarchy

The hierarchical architecture of biological materials has become an increasingly important source of inspiration for material scientists in recent years. In nature, a uniquely successful strategy to obtain materials with specially designed physical properties with a minimum of material is by cooperative alignment of structural features on different length scales. The main objective of the present Hertha Firnberg project is to produce bio-inspired hierarchically structured cellular ceramics. On a macroscopic level, rapid prototyping (RP) will be used to produce artificial cellular structures on the mm and sub-mm scale. On the nanometer level, meso-structured silica will be obtained by cooperative self-assembly of silica and surfactant molecules. The major challenge in combining these levels into a hierarchical material is to bridge the gap between the macroscopic and the nanometer levels that are 4-5 orders of magnitude apart in size. Our solution to this problem will be to use of biological fibers and foams as intermediate links and exploit their already available natural microstructure to direct the self assembly of the nanostructured silica / surfactant composite. Different strategies such as electric and magnetic fields, shear forces and capillary forces will be used to achieve preferred alignment of structural elements on all hierarchical level. In doing so we will explore pathways to achieve a `concerted action` of structural features, similar to that observed in nature, and attempt to obtain ceramic and ceramic /organic composite materials with physical properties not achieved with conventional methods. State of the art methods will be used for structual characterization and mechanical and thermal studies of the material, to accompany the project and provide essential feedback at every step of development. The project is designed for three years and will be carried out at the Vienna University of Technology, group of Prof. Sabine Seidler. Seidler`s group is already working extensively in the field of cellular ceramics and an additional FWF project along these lines is granted. These settings will provide an ideal background for the applicant to implement her scientifific experience gained abroad through her previous post-doctoral stay in the US, University of California Santa Barbara, group of Galen D. Stucky, to pave the way for her future academic career and contribute to the scientific advancement of materials science in Austria.