J2-9440 Characterization of fractal structures and scale-up parameters in their synthesis

The main purpose of the project is to set up a general methodology for planning and preparing fractal structures for particular application.

Many important areas of research and technology, such as catalysis, separation processes, sensors, immobilized bioreactors, etc., requires materials exhibiting high specific surface area, high porosity and open porous structures with high accessibility. Ideally such material would have defined structure already at nanoscale but being flexible enough to be tailored for specific application.

Learning from nature, once can realize, that such structures do already exist and that are rather common. They are formed through crystal twinning. Crystal twins are defined by geometric operation, where two or more crystals are in contact or do interpenetrate according to defined and repetitive rules, predetermined by their crystal lattice. Because of that, such structures do form in nanoscale, microscale or macroscale dimensions. In case of multiple generation twinning, they form self-similar structures. In fact, they are natural fractals, precisely geometrically defined by twinning laws. Despite variety of such natural structures scientist were only recently able to synthetize multi-generation twins in laboratory. This opens possibility for preparation of tailor made fractal structures based on twinning laws and therefore theoretical characterization of their properties is required for design of fractal structures with required properties.

During project several different fields of expertise will be combined to determine and synthetize optimal multiple-generations twin structures-shorter crystal fractal structures (CFS)- for particular application. Based on the knowledge of particular mineral atomic structure, possible contact twins and especially frequency of their occurrence will be determined. For most frequently occurring CFS their structural properties using fractal theory will be determined, while their hydrodynamic properties are planned to be estimated using computational fluid dynamic (CFD) tools in cooperation with Austrian partner.  In parallel, synthetize of larger quantities of specific CFS will be performed and experimental results will be compare with theoretical predictions. Optionally, CFS would be functionalized to tailor their surface properties accordingly to test adsorption and separation properties for biological molecules of different size. Entire procedure is planned to be tested on several minerals what would result in general methodology for design and preparation of such structures for particular application.

The project is cofunded by the Slovenian Research Agency ARRS.