The dissertation deals with the synthesis and characterization of low dimensional nanostructures and their functionalization. By utilizing polyelectrolytes that served as nanoreactors for the in-situ synthesis of metallic nanoparticles on the surface of titanate nanobelts, Ines Bračko synthesized nanocomposites with controlled size and homogenous distribution of nanoparticles. Such nanocomposites with silver and copper nanoparticles exhibit enhanced photocatalytic activity in UV and visible region.
D.09 Tutoring for postgraduate students
COBISS.SI-ID: 262821632In her doctoral thesis Marija Vukomanović presented a new sonochemical approach for the synthesis of silver (Ag), platinum (Pt) and gold (Au) nanoparticles and their composites with hydroxyapatite (HAp). The major goal was to design physicochemical properties of material in order to achieve: (i) intensive antibacterial activity and (ii) maximal reduction of toxicity for humans and their environment.The first part of the thesis was devoted to the preparation of HAp/Ag, which is characterized with high antibacterial activity. It confirmed that reactive oxidative stress driven by reactive radicals is the major mechanism of its action. A non-selectivity of this mechanism is a major source of very high toxicity of this metal for human cells. The solution for this problem represent the composites HAp/Pt and HAp/Au. Different interactions of the composites with light was achieved by surface functionalization, what was the reason for different properties. Newly developed HAp/Pt and HAp/Au composites are good alternatives to composite with silver. HAp/Pt possesses ability for self-cleaning while HAp/Au has intensive antibacterial activity.
D.09 Tutoring for postgraduate students
COBISS.SI-ID: 262427392D. Suvorov was elected for President of the European Ceramic Society
E.02 International awards
This Plenary lecture describes that apart of crystal chemistry and crystal structure it is mostly the microstructure that governs the properties of functional ceramics. We have identified several features in microwave and thermoelectric ceramics, which influence development of the microstructure and consequently influence dielectric and electrical properties of the materials. In the Zn-containing complex microwave perovskites sublimation of ZnO creates B-site vacancies, which tend to order forming hexagonal close-packing sequences within the cubic matrix. In the microstructure this is manifested as lamellar features that act as a template for anisotropic exaggerated grain growth. Furthermore we found that hexagonal perovskites can form coherent intergrowth structures with the cubic perovskites as an intermediate phase in the long-range ordering process. In the case of CaTiO3-REAlO3-based ceramics the microstructure evolution is governed by the octahedral tilting transitions that occur upon cooling from the sintering temperature and result in the formation of antiphase and twin domain boundaries. Furthermore, the microstructure is influenced by the formation of a hexaluminate-based transient phase during the calcination process, which leads to the formation of vacancies in the perovskite matrix. The intergrowth of two structural types of layered cobaltates NaxCoO2 and Ca3Co4O9 causes texturing that critically influences electrical conductivity. The control over the formation of such microstructural features and their role in tailoring the electrical response of a material was discussed in the presentation.
B.04 Guest lecture