The structure and photocatalytic properties of ceramic membranes synthesized on the basis of amorphous potassium polytitanate intercalated with nickel ions have been investigated. It is shown that the phase composition of the synthesized ceramics depends on the firing temperature: at 650 ° C it is formed from NiTiO 3 , TiO 2 and the residual potassium titanate amorphous phase; at 850 ° C - NiTiO 3 crystals, mainly represented in the surface layer of TiO 2 membranes, and a complex oxide of the composition K (Ti, Ni) O 16.5 , which has a golandite-like structure and is represented mainly in the structure of the inner layers of ceramics.
Tab. 2, ill. 5, bibliography: 10 titles.
The possibility of obtaining a transparent ceramic material based on yttrium oxide with the addition of scandium oxide and neodymium oxide has been investigated. The modes of heat treatment of the charge and roasting in vacuum have been established. A transparent ceramic material with a direct light transmittance of 68% in the visible region of the spectrum and a sintering temperature of 1800 ° C was obtained. Il. 7, bibliography: 5 titles.
The relationship of the aesthetic properties of porcelain (whiteness and color), its structure and technological factors are considered. The research results demonstrate the possibility of regulating the whiteness of porcelain using high-quality raw materials, mineralizing additives, and optimal firing modes. The use of various methods for determining the whiteness and color of porcelain makes it possible to assess the influence of technological factors on the formation of the color characteristics of the material. Possibility of correlation of values ??of porcelain whiteness determined on spectrophotometers "Spekol" and "Pulsar" has been established. Tab. 3, ill. 4, bibliography: 6 titles.
Methods for determining the dependence of the average distance between particles in monodisperse composites are analyzed. A refined method is proposed for determining the average distance between particles in dispersed systems with an indication of the coordination number, taking into account the volumetric density, system connectivity and the degree of its compaction on the basis of corpuscular and percolation models. A comparison of the calculations by the refined technique with the experiments showed their good agreement. The technique is applicable for composite, porous and colloidal systems. Il. 1, bibliography: 11 titles.
The features of the technology of new types of refractory and heat-insulating materials with high porosity, obtained by duplicating the cellular structure of the polymer base (polyurethane foam) and using the technology of chemical pore formation based on the process of "cold" swelling of inorganic compositions, are considered. The use of electrocorundum, periclase, spinel, zirconium dioxide as a base allows the use of such materials within the temperature range from 1750 to 2200 ° C. In some cases, the developed heat-insulating materials can successfully replace corundum fibrous materials. Tab. 1, ill. 7, bibliography: 2 titles.
The influence of the hydrothermal method for the synthesis of initial powders using chemical reagents and illite clay as initial components on both the phase composition and structure and some properties of mullite-zirconium ceramics has been studied.
It is shown that mullite, ZrO2 tetragonal modification predominates in the sintered ceramic material, there are also closed pores. With an increase in the firing temperature and especially with the addition of illite clay, the sinterability and, consequently, the compressive strength increase. The modulus of elasticity with an increase in the temperature difference up to 1000/20 ° С, as with the addition of illite clay, during thermal shock increases to 35 and 95 GPa, respectively, while at 500/20 - up to 20 and 22 GPa.
Tab. 2., ill. 8, bibliography: 16 titles.
The results of studies on the synthesis of ceramic pigments using silica gel and quartz sand are presented. The relationship between the temperature of synthesis and composition with the color characteristics of pigments has been established. The expediency of obtaining pigments using quartz sand is shown. Introduction of transition metal oxides (CoO, NiO, Fe 2 O 3 , Cr 2 O 3 ), mineralizers ( H 3 BO 3 , Na 2 CO 3 , NaF) and modifiers (ZnO, CaO, MgO) obtained wide palette of pigment colors. Tab. 4, ill. 4, bibliography: 3 titles.
The reactions of synthesis of diopside ceramic pigments using natural minerals - talc and wollastonite are investigated. With a non-stoichiometric ratio of the starting components in two of the three reactions studied, the yield of the main reaction product, diopside, increases, while in the third reaction, a change in the stoichiometry of the incoming components leads to a decrease in the diopside content. It is noted that with a slight deviation from stoichiometry, the dominant crystal structure of the pigment changes, which entails a radical change in its color. Tab. 3, ill. 4, bibliography: 5 titles.
A new composite ceramic material based on corundum reinforced with multilayer carbon nanotubes (CNTs) obtained by catalytic pyrolysis has been developed. The modes of vacuum roasting and preliminary treatment of the initial charge have been worked out; the composition of the ceramic matrix, the concentration of CNTs and other technological parameters have been optimized. A uniform distribution of CNTs over the entire volume of the ceramic matrix is ??achieved. As a result, a composite with a network-frame structure of CNT distribution was obtained, demonstrating an increase in crack resistance by a factor of 1.5 - 2. Tab. 2, ill. 5, bibliography: 7 titles.
The use of pegmatite of the Chupinskoye deposit with admixtures of mica for the production of porcelain glaze may cause the formation of a "prickly" glaze defect. It was found that the introduction of calcined kaolin into the composition of the cobalt feldspar glaze reduces the likelihood of this defect formation. Tab. 1, bibliography: 4 titles.
