The porous cordierite ceramics were prepared using six clay mineral mixtures of talc, kaolinite and Mg-vermiculite, which has not been used for cordierite synthesis till now. The basic cordierite precursor was mixture consisted of talc, kaolinite and alumina. Other mixtures contained clay minerals and/or alumina with the stoichiometric MgO, SiO2 and Al2O3 ratio close to cordierite, 2MgO·2Al2O3·5SiO2. Ceramic samples contained cordierite enstatite and corundum. Pure cordierite formed from kaolinite nad vermiculite. Vermiculite contributed to the formation of large pores, alumina influenced struts architecture. The porosity of cordierite ceramics was in the range from 46% to 70%. Cordierites showed structural geometry close to the high-temperature hexagonal α-Mg cordierite

Certain optical parameters of nano and micro-structured particles of silica were adjusted and the measurement of the particle size distribution was obtained by using the Mastersizer 2000 device. The optical method process may be used by looking for unique refractive and absorption index of investigated particles. Optical properties (i.e., refractive index) and absorption index of the silicon particles have been found and related to inter-particle silicon bindings in the form of Hamaker constants. For the optical properties, calculations using the Mastersizer 2000 Mie Scattering solutions representing the electric and magnetic induction (i.e., silica's permeability and permittivity from Maxwell's equations) were employed. The silicon nanoparticles were prepared by the water jet mill technology and the research has revealed that the silicon particles were detected in the substance as nanoparticles characterized by the silica optical parameters

The demand of nanocomposites for filler properties which is expected utilization. Natural minerals are keeping one of the prior positions in that significance. The thermal properties and strength of the requested properties expected to be improved for polymeric materials. Modification of that layered materials is still necessary to assure the compatibility of the filler with polymer with non-polar character. The organically modified montmorillonite is still the most frequently studied mineral for the application as the filler. Comparing montmorillonite and vermiculite we can note the difference in layer charge of silicate layer. Thus the vermiculite with higher charge could be more stable. Modification of jet milled vermiculite with amine and phosphonium salts using thermal treatment was performed using 10% of organic amount. The changes of interlayer space of samples after intercalation and nanocomposites were studied using X-ray diffraction analysis. Higher degradation temperature for nanocomposites with vermiculite was defined using thermogravimetry

Organovermiculites with three different loadings of organic matter were prepared using hexadecylpyridinium (HDP) cations. The prepared materials were characterized with XRD analysis enabling the total organic carbon content to be derived. The naphthalene sorptive properties were also tested. The material behavior was compared with organovermiculites modified with hexadecyltrimethylammonium (HDTMA) cations. The experiments showed that HDP vermiculite is a better sorptive material for aqueous solutions as compared to naphthalene vapor which is less efficient than found with HDTMA vermiculite. Simulation of a possible HDP ordering in the vermiculite interlayer gallery was performed using a molecular modeling environment

In the paper two new experimental setups at the Institute of Physics of the VŠB—Technical University of Ostrava for measurements of solid and liquid samples using the excitation surface plasmon resonance (SPR) method are described. Preliminary results of refractive index specifications of aqueous NaCl solutions at five different laser wavelengths are report

V článku uvedeno Hlaváč, L.M., Hlaváčová, I.M.Disintegration of the brittle material particles by water jet takes place during generation of the injection abrasive water jet just in the mixing process inside the mixing chamber and the focusing tube. The physical limits of these processes are the topic of the theoretical investigation the results of which are presented in this paper. The mean particle size resulting from the mixing process can be evaluated from the mean particle size of the input material particles and basic water jet parameters using the theoretical equation. The equation is used for explanation of the basic problems of particle grinding by water jet. Some propositions are made for improvement of the water jet grinding process. The primary disintegration process, taking place in the mixing chamber and focusing tube, can be followed up by subsequent intensifying processes—interaction with rigid target or collision with opposite jet of the same type. The second mentioned is just investigated and the basic theoretical postulations of its efficiency are formulated. The theoretical studies are supported by results of experiments aimed at the disintegration processes inside the mixing chamber and the focusing tube and then at the opposite jet collision. All theoretical and experimental conclusions are analyzed from the economical point of view and the most important conditions for both the laboratory and the industrial use of this type of mineral comminution and pulverization are submitted