Příprava a charakterizace nových forem keramických nanokompozitů na bázi modifikovaných jílových minerálů

Abstract

This dissertation thesis deals with the preparation and follow-up characterization of new forms of porous magnesium ceramic materials on the basis of natural clay minerals talc, vermiculite, kaolinite and montmorillonite. Type and amounts of clay minerals in preceramic metres, shape and size of particles and also different procedures of preparation influence the resulting ceramic properties after their sintering. The suitable chemical modifications of initial clay minerals in preceramic mixtures may purposely alter the resulting ceramic properties. This study is focused especially on magnesium cordierite and steatite ceramics whose common feature is presence of talc in preceramic mixtures. In the first part, clay minerals talc, kaolinite and unconventionally vermiculite used were prepared as preceramic mixtures for sintering of porous cordierite ceramics. The new forms of zircon/cordierite and photocatalytic active CeO2 ceramics were prepared by using chemically modified vermiculite by zirconyl chloride and/or CeO2, respectively. The second part is focused on the preparation of porous steatite ceramics from preceramic mixtures containg talc, kaolinite and/or montmorillonite and Na2CO3. The natural and mechanochemically treated talc were used for prepration of these statite ceramics. The prepared magnesium ceramic materials were characterized by combination of methods of X-ray diffraction analysis, scanning electron miscroscopy and porosity measurement.