Using the methods of the cocrystallization and coprecipitation of hydroxides, xerogels and powders based on zirconium dioxide are synthesized and ceramics based on them are obtained. The influence of the synthesis conditions on the physicochemical properties of the obtained materials is assessed.

Finely dispersed СeO2–Nd2O3 and Gd2O3–La2O3–SrO–Ni(Co)2O3–δ mesoporous powders are synthesized by co-crystallization of the corresponding nitrates solutions with ultrasonic treatment and used to prepare nanoceramic materials with a fluorite-like, orthorhombic perovskite and tetragonal perovskite crystal structures respectively with CSR ~ 55–90 нм (1300ºC). The study of physicochemical properties of the obtained ceramic materials revealed an open porosity 7–11% for СeO2–Nd2O3 and 17–42% for Gd2O3–La2O3–SrO–Ni(Co)2O3–ä. Cerium oxide-based materials possess a predominantly ionic electrical conductivity with σ700ºС = 0.31 · 10–2 S/cm (ion transfer number ti = 0.71–0.89 in the temperature range 300–700°C) due to the formation of mobile oxygen vacancies at heterovalent substitution of Nd3+ for Се4+. Solid solutions based on lanthanum nickelate and cobaltite feature a mixed electronic-ionic conductivity with σ700°С = 0.59 ∙ 10–1 S/cm with the electron and ion transfer numbers te = 0.92–0.99 and ti = 0.08–0.01. The obtained ceramic materials are shown to be promising as solid oxide electrolyrtes and electrodes for medium temperature fuel cells.

Using the method of the joint crystallization of solutions of nitrate salts with ultrasonic treatment, xerogels and highly dispersed mesoporous powders of the following composition are synthesized: (CeO2)1 – x(Nd2O3)x (x = 0.02; 0.05; 0.10), Gd1 – xSrxCo0.5O3 – δ (x = 0.1, 0.15, 0.2, 0, 25), Gd0.4Sr0.1Ni0.5O3 – δ, and Gd0.125La0.125Sr0.25Co0.5O3 – δ; and based on them, nanoceramic materials with a crystalline cubic structure of the fluorite type, as well as an orthorhombic and tetragonal structure of the perovskite type with CSR 55–90 nm (1300°С), respectively, are obtained. The physicochemical properties of the resulting ceramics are studied; it is revealed that it has an open porosity of 7–11

Методом совместной кристаллизации растворов азотнокислых солей с ультразвуковой обработкой синтезированы ксерогели, высокодисперсные мезопористые порошки состава: (СeO2)1-x(Nd2O3)x (x = 0,02; 0,05; 0,10); Gd1–xSrxCo0,5O3–δ (х = 0,1, 0,15, 0,2, 0, 25); Gd0.4Sr0.1Ni0,5O3–δ; Gd0,125La0,125Sr0,25Co0,5O3–δ — и на их основе получены нанокерамические материалы с кристаллической кубической структурой типа флюорита, орторомбической и тетрагональной структурой типа перовскита с ОКР ~55–90 нм (1300◦С) соответственно. Изучены физико-химические свойства полученной керамики; выявлено, что она обладает открытой пористостью 7–11% для состава: (СeO2)1-x(Nd2O3)x и 17–42% для материалов состава Gd1–xSrxCo0,5O3–δ, Gd0.4Sr0.1Ni0,5O3–δ и Gd0,125La0,125Sr0,25Co0,5O3–δ. Материалы на основе оксида церия обладают преимущественно ионным (числа переноса ионов ti = 0.71–0.89 в интервале 300–700◦С) типом электропроводности, обусловленным образованием подвижных кислородных вакансий при гетеровалентном замещении Се4+ на Nd3+; σ700ºС = 0.31·10–2 См/см. Твердые растворы на основе никелата и кобальтита лантана обладают смешанной электронно-ионной проводимостью, σ700ºС = 0.59∙10–1 См/см с числами переноса te = 0.92–0.99 ti = 0.08–0.01. Показана перспективность использования полученных керамических материалов в качестве твердооксидных электролитов и электродов среднетемпературных топливных элементов.

This article describes the production of nanodisperse xerogel and powders (average CSR size of 9 nm) in the ZrO 2 –Y 2 O 3 –Al 2 O 3 system by coprecipitation of hydroxides. A strong highly porous ceramic has been produced from the initial powder with the composition of [(ZrO 2 ) 0.97 (Y 2 O 3 ) 0.03 ] 0.8 (Al 2 O 3 ) 0.2 with pore forming additives using patented solid phase sintering. Using Doppler sonography, the volume of blood flow in arteriolas and capillaries has been estimated 150 and 250 days after implantation of plates. Therefore, the microcirculatory Doppler sonography seems to be a promising intravital method of estimating blood flow in the zone of plates from biocompatible nonresorbable material and, probably, inside the plates. It has been found that the ceramic plates based on zirconium dioxide in the body of experimental animals do not result in a negative reaction of animal’s body. The in vivo experimental results make it possible to state that the obtained bioceramic based on zirconium dioxide is a promising material for endoprosthetics.

Nanodispersed xerogels and powders (average size 9 nm) were obtained by co-precipitation of hydroxides in the ZrO2–Y2O3–Al2O3. Solid-state sintering of samples from the initial [(ZrO2)0,97(Y2O3)0,03]0,8(Al2O3)0,2 powder with pore-forming additives using a patented technology strong highly porous ceramics was produced. Dopplerography was used to assess the volume of blood flow in arterioles and capillaries on 150 and 250 days after implantation of the plates. Thus, microcirculatory Doppler sonography seems to be a promising intravital method for assessing blood flow in the plate location area and, possibly, inside the plate. It was found that ceramic plates based on zirconium dioxide, placed in the body of experimental animals, do not cause a negative reaction of the animal’s body. The results of studies under in vivo conditions suggest that the obtained bioceramic based on zirconium dioxide is promising for use as a material for endo-prosthetics.

Mesoporous nanosized aerogels, xerogels, and powders in the ZrO2–Y2O3–CeO2 and ZrO2‒Y2O3–Al2O3 systems have been obtained by liquid-phase synthesis methods. The thermolysis, phase composition, and textural features of the synthesized materials have been studied. It has been found that the predominance of Lewis acid sites (LASs) on the surface of their particles indicates its lower hydroxylation and, as a consequence, a lower degree of agglomeration of the obtained materials.

By the method of joint crystallization of solutions of nitrate salts highly dispersed powders of the composition: La1 – xSrxNiO3, La1 – xSrxCoO3 and La1 – xSrxFe0,7Ni0,3O3 (x = 0,30; 0,40) were synthesized. They have a specific pore volume of 0.018 – 0.035 cm3/g and a specific surface area of 15 – 31 m2/g. On their basis, ceramic nanomaterials of a given composition with CSR ~ 64 – 70 nm (1300 °С) were obtained. The physical and chemical properties of the obtained ceramics were studied; it was revealed that it is a solid solution with open porosity in the range of 17 – 30 %, high values of the relative density of 94 %. In terms of their physical and chemical properties (open porosity, density, coefficient of thermal expansion), the obtained ceramic materials are promising as solid oxide cathodes for medium-temperature fuel cells.

Paint coatings based on a copolymer of vinyl chloride with vinyl acetate with an additive of epoxy-diane resin of six different compositions are developed. The coatings differ in the nature of fillers (anatase, rutile, and cobalt and lanthanum oxides) and the composition of soft biocidal additives of the atrane class (protatrane of salicylic acid and hydrometallatranes based on triethanolamine complexes with zinc(II) and copper(II) salts). The process of biofouling in the natural conditions of the White sea is studied. Fouling communities formed on the studied plates during 2.5 months of exposure to the sea is analyzed, depending on the composition of the coatings. The fouling is based on the attached forms: scyphistomas (polypoid stage) of jellyfish Aurelia aurita and Cyanea sp., mussels Mytilus edulis, and hydroid Obelia longissima. The efficiency of the same paint coating appear to differ towards different species of fouling organisms.

— Xerogels in the ZrO 2 (Y 2 O 3 )–Al 2 O 3 system are obtained by the coprecipitation method followed by a low-temperature treatment at –25°C for 24 h. The physicochemical properties of the powders of ZrO 2 (Y 2 O 3 )– x Al 2 O 3 ( х = 15, 20, and 25 mol %) compositions obtained by burning the xerogels are studied. It is shown that the introduction of 25 mol % of Al 2 O 3 promotes the deceleration of the growth of the particles of the t -ZrO 2 (Y 2 O 3 ) tetragonal solid solution. It is established that the obtained powders are characterized by high values of the degree of tetragonality ( c / a = 1.438–1.436).

The physical-chemical and technological factors determining the selection of initial components for film-forming sol-gel composites obtained by mixing silica sols containing different dopants and dispersed oxides has been discussed on specific examples. Their effect on phase composition, structure, and the electrophysical properties of the fabricated electro-insulating glass ceramic coatings has been analyzed. The fabricated coatings serve to be applied in electrical engineering, in particular, for the protection of glass bulbs of X-ray tubes operated at high voltage (up to 160 kV).

Composite xerogels based on a phosphosilicate matrix filled with nanodiamonds were synthesized by sol-gel processing. The crystalline and fractal characteristics of the initial nanopowders were obtained using wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS) techniques. Proton-conducting nanocomposite membranes of fuel cell applications were fabricated from the xerogels. The WAXS data on the nanodiamonds show diffraction patterns characteristic of graphitized ultradisperse nanodiamonds or pure nanodiamonds. The Beaucage plots of the phosphosilicate-nanodiamond composites show a multi-level fractal structure of the type of the surface fractal/mass fractal. The fractal characteristics such as the size and the gyration radius of the aggregates were calculated from the plots. The conductivity-frequency curves show that the conductivity is high and increases with the nanodiamond content in the composites.