čas: 23.4.2021 01:58:54
Obnovit | RAW
Department of Glass and Ceramics
List of available PhD theses
Ceramics with controlled properties in CaO-Al2O3-SiO2 system
Ceramic materials in the CaO-Al2O3-SiO2 system are used for many applications. Materials with controlled delay in the area of small length changes during firing are possible to prepare by suitable composition of raw materials and their subsequent heat treatment. The work will be focused on the prediction of mixtures behavior in the field of the area of small length changes and characterization of final products.
Clinkerless hydraulic ternary binder
The aim of the dissertation thesis is the preparation of a clinkerless hydraulic ternary binder with lower energy requirements and lower CO2 emissions in comparison to Portland cement, and which contains amorphous C-A-S-H as the binder phase. The development of the binder would be aimed at the lime activation of aluminosilicates, especially calcined clays. The work would also include a study of the reactivity of calcined clays from low quality and waste kaolinitic rocks. Another raw material of the binder would be waste gypsums. Hydration products would be study by a number of methods: XRD, SEM + ED, IR, or NMR Solid State, TGA and porosimetry. The work would include the determination of mechanical properties of the prepared ternary binder after the hydration period in a time horizon longer than 1 year. The work is part of an effort to increase the durability of concrete, because modern concrete has the lower durability in comparison to Roman concrete, which has resisted to atmospheric and sea water condition for more than 2,000 years. It turns out that in Roman concrete the main binder phase is C-A-S-H, which is attributed to the high durability of Roman concrete.
Coating for induction heating of glass
Effective properties of oxide and silicate ceramics and their dependence on composition, microstructure and temperature
This work concerns the effective properties of oxide and silicate ceramics, with a focus on the relations between composition, microstructure and elastic, thermophysical, thermoelastic, dielectric and piezoelectric properties. The student’s work includes the characterization of phase composition and grain size via X-ray diffraction, the microstructural characterization via microscopic image analysis, analytical calculations of effective properties via micromechanics (homogenization theory) for statistically isotropic and anisotropic (transversally isotropic) polycrystalline materials, analytical calculations and numerical modeling (computer simulation) of effective properties of multiphase materials (isotropic and transversally isotropic) and the comparison of theoretical predictions and the results and experimental measurements on real materials.
Elastic, dielectric and piezoelectric properties of ceramics and composites
Elastic, dielectric and piezoelectric properties are of fundamental importance for many types of functional ceramics and composites. Figures of merit for these materials, e.g. ceramics for hydrophone applications, are usually determined by a complex interplay of these three types of properties. This PhD topic focuses on the study of the dependence of the effective elastic, dielectric and piezoelectric properties on the microstructure, mainly porosity, pore shape and grain size (in the case of composites also volume fraction). The student is required to have a background in materials science (not necessarily specialized on ceramics) and an interest in challenging theory (full tensor formalism for second-, third- and fourth-order tensors), computer modeling and experimental work with real-world materials.
Glazes with controlled reflectance
Ceramic materials are surface-treated by applying different types of coatings, the most common surface finishing of ceramic products are glazes- stable glassy coatings. By using suitable additives / pigments in glazes, the final properties of a ceramic product, such as roofing tilles, can be adjusted. The dissertation will focus on the preparation of glazing with controlled reflection of "cool roof" systems.
Interaction of glass containing biogenic components with aqueous solutions
In addition to the traditional use of glass as containers or in the building and automotive industries, some glass can be used in medicine, pharmacy or agriculture. The aim of the thesis will be to explore and describe the kinetics of interaction of appropriately selected or prepared soluble phosphorous and phosphosilicate and glass with other biogenic components) with aqueous solutions simulating soil or body environment and to design glass that can be used as slowly soluble fertilizers or bioresorbable materials in medicine.
Large deformations of ceramic powder compacts and fracture of porous and cellular ceramics
Large deformations play a significant role in ceramic technology, because all pressing operations rely on the quasi-plastic behavior of powder systems during consolidation. On the other hand, also porous and cellular ceramics, including those produced via additive manufacturing, e.g. 3D printing, exhibit quasi-plastic behavior during compression. This PhD topic combines theory-based analytical modeling and computer-based numerical modeling of large deformations with real-world experiments performed on ceramic materials via different mechanical tests, mainly axial and diametral compression. The student is required to have a solid background knowledge in ceramic science and technology as well as the ability to combine computer modeling with experimental work on real materials from both fine and coarse ceramics.
New method of in vitro test of glass and glass-ceramic materials for bone tissue replacement
Substitution of hard bone tissue by glass, glass-ceramic, or ceramics material is a common practice today. Each, potentially bioactive material has to be studied by a series of in vitro and in vivo tests. In vitro tests used for an inorganic biomaterial is now described in ISO 23317:2014. Nowadays, this standard is obsolete and needs a general revision. The recommended form of the tested material (solid discs) and testing solution (Simulated Body Fluid - SBF) seems to be not suitable. SBF simulates the inorganic part of blood plasma and is buffered with TRIS+HCl buffer. However, this buffer interacts with the tested glass and shifts the in vitro test results to false-positive values. This work will be focused on the setting of the new conditions of in vitro tests for better characterization of tested biomaterials.
Precipitation of calcium phosphates during interaction of biomaterials with simulated body fluids
The study will be oriented on precipitation of calcium phosphates from selected simulated body fluids. The aim is to experimentaly measure the kinetics of phosphates precipitation and describe it using chosen or newly developed physico-chemical models
Refractory geopolymer material
The aim of the dissertation thesis will be the preparation of a refractory geopolymer material formed by alkaline activation of aluminosilicates. Industrial and waste materials such as metakaolins, fly ash and blast furnace slag are considered as a source of aluminosilicates. The work will include the study of various possibilities of alkaline activation of aluminosilicates and the influence of refractory fillers. The workability and solidification and hardening processes of the prepared materials will be studied. Part of the work will include the determination of refractory and thermomechanical properties of prepared materials, which include flexural strength at high temperatures and heat resistance. The prepared geopolymers will be studied by a number of methods, such as XRD, SEM, NMR, DTA and mercury porosimetry.
Silicate glass surface
Glass surface is not fully explored, but the surface features are closely related to its mechanical and chemical properties. The work will focus to glass surface preparation, its characterization and well-defined modification. The relation of the surface with some properties will be further studied.
Structure of glass and its interfaces
Glass structure is described by means of structural quantifiers (radial distribution functions, coordination numbers, Q-motifs, rings, etc.) on various geometrical and topological levels. Structure can be theoretically mimicked by Molecular dynamics on the atomic level. The work aims to the theoretical description of glass structure and its relation to the glass transition. Except for the theoretical description, simulations of the chosen amorphous systems and their interfaces will be utilised.
Suspension rheology – from theoretical foundations to practical applications
The rheology of suspensions is a topic of widespread interest that is important in ceramic technology and many other fields. This PhD topic involves the theoretical treatment of basic problems in suspension rheology, mainly the dependence of the effective viscosity on particle shape, size and size distribution, as well as practical work with purely viscous non-Newtonian fluids as well as viscoelastic systems, mainly using rotational viscometry and oscillatory rheometry. The student is required to have a general chemical engineering background, not necessarily based on (and by no means limited to) ceramic technology.