Bioglass 45S5 was doped with bismuth oxide in concentrations up to 40 wt

In this work, we investigated «in vitro» properties of boron-containing glass based on «Bioglass 45S5» by pyrolysis method of a liquid organic phase. It was found that 15 wt. % B2O3 bioglass has improved characteristics compared to the original composition. The inclusion of B2O3 in the composition of the material allows to reduce alkalization of the environment and the degradation rate of bioglass 45S5. Doping does not suppress the bioactivity of the material. The cytotoxicity of boron-containing glass is comparable to that of 45S5 glass. This indicates the safety of its use in medicine. The obtained material is intended to create bioactive coatings on implants, as well as fillers for various materials to impart bioactive, antibacterial and antibiofilm properties to them. The composition holds promise for bone implantology in modern medicine.

Abstract—New methods for the synthesis of NASICON of the composition Na1 + xZr2P3 – xSixO12 (0 ≤ x ≤ 3) were presented. In the work, the method of pyrolysis of organic solutions was used, which takes a minimum time to synthesize the material. Various options for the composition and heat treatment of precursors were considered. The effect of rosin on the pyrolysis process and the phase composition of the final products was discussed. The optimal conditions for the synthesis of the low-dimensional monoclinic polymorph Na3Zr2Si2PO12 with homogeneous composition were determined.

Glass and glass ceramics containing 40 wt.

The effect of the excess of Na, Si, and P on the composition of Na1 + xZr2P3 – xSixO12 (0 ≤ x ≤ 3) silicophosphates is studied; the samples are obtained by the pyrolysis of organic solutions in a rosin melt. The samples are studied by x-ray diffraction analysis, scanning electron microscopy, and the Rietveld method. It is established that specific concentrations of Na, Si, and P additives affect the impurity content in the synthesis products and change the phase composition of Na1 + xZr2P3 – xSixO12.

Using the method of pyrolysis of solutions in a melt, the phase formation of sodium and zirconium silicophosphates Na1+xZr2SixP3–xO12 was studied depending on the concentrations of sodium and phosphorus in the precursors. The influence of the content of these components, as well as firing conditions on the change in the ionic conductivity of NASICON was studied. Methods of X-ray phase analysis, scanning electron microscopy, full-profile Rietveld analysis, and electrochemical impedance spectroscopy were used. The specific values of grain conductivity (σb) and grain boundaries (σgb) of the samples were calculated. It was found that the reason for the change in ionic conductivity is a change in the composition of NASICON with increasing concentrations of sodium and phosphorus in the precursor. The main condition for high conductivity of the material is the formation of a crystalline phase corresponding to the composition Na3Zr2Si2РO12, as well as a minimum amount of impurities and glass phase. The conductivity of the NASICON sample (x = 2) under certain processing conditions is ~ 1 · 10-3 S/cm.

The paper presents a method for the synthesis of functional glass-ceramic materials based on Bioglass 45S5 by pyrolysis of a mixture of organic solutions. Samples of bioglasses doped with zirconium(IV) and tantalum(V) oxides were obtained. The influence of doping on the properties of bioglasses was studied by the following methods: XRD, SEM, EDX. A change in the physical and chemical properties of Bioglass 45S5 with an increase in the content of a functional additive has been established. The obtained materials are promising for modern medicine and can be used to restore bone tissue, as well as to treat malignant neoplasms.

The interaction of tungsten mineral raw materials with a mixture of NH 4 HF 2 and (NH 4 ) 2 SO 4 upon heating was studied. It was determined that, first, at temperatures up to 200°C, the incoming components are fluorinated to form complex and simple fluorides. A further increase in temperature is accompanied by the decomposition of ammonium sulfate to form NH 4 HSO 4 , which leads to the conversion of fluorides into sulfates and of the tungsten ammonium fluoride complex into tungstic acid H 2 WO 4 . It was shown that water leaching of the product of the decomposition of tungsten-containing mineral raw materials with a mixture of NH 4 HF 2 and (NH 4 ) 2 SO 4 makes it possible to extract tungsten from mineral raw materials in the form of the commercial product WO 3 .

A new promising method for the synthesis of NASICON (Na3Zr2Si2PO12) by pyrolysis of organic solutions has been developed. Sodium oleate, zirconyl oleate, tributyl phosphate, and tetraethoxysilane have been used as precursors. The molar ratios of the components of the mixture for the formation of NASICON have been established. The effect of sodium on the formation of the zirconium dioxide phase has been proven. A finely dispersed material with an average grain size of 0.2 µm has been obtained. Changes in morphology and composition depending on the time and temperature of firing the sample are studied. The results have been confirmed by X-ray powder diffraction and scanning electron microscopy. To refine the parameters of the crystal lattice, a full-profile analysis has been performed by the Rietveld method. The process of obtaining NASICON takes about 9 h, i.e. it is the least time consuming of all the alternative ways of synthesis. The advantages of this method are the possibility of lowering the sintering temperature, the absence of the need to control many parameters during synthesis, and minimizing the duration and multi-stage process. The method contributes to the development and production of more promising ion-substituted structures.

A new method for preparing Na 1 + x Zr 2 Si x P 3 – x O 12 (0 < x < 3) based on pyrolysis of solution containing a mixture of organic components in rosin melt has been proposed. Effect of superstoichiometric amounts of sodium and phosphorus on the phase composition of synthesis products has been proved. It has been found that precursor for the sample of maximal purity of phase composition is prepared at molar ratio Na : Zr : Si : P = (1.15 + x ) : 2 : x : ( y – x ), where y = 3 (1.20 + x )/(1 + x ). Precursor calcination temperature is 1000°C. Different NASICON compositions without crystalline admixtures have been obtained in the range 1.5 ≤ x ≤ 2.12. The prepared samples have been studied by X-ray powder diffraction and scanning electron microscopy. The disclosed method of synthesis is promising for the preparation of NASICON as both bulk materials and thin layer coatings.

NASICON with a composition of Na 3 Zr 2 Si 2 PO 12 was first synthesized by pyrolysis of a mixture of organic solutions. The ratio of initial components required for the formation of this composition was determined. The temperature conditions for processing the precursor were examined. The material was obtained with an average grain size of 0.2 μm. The composition and morphology of the compound were confirmed by X-ray diffraction analysis and scanning electron microscopy. The synthesis of NASICON takes 9 h on the average, which is the minimum time among all known methods for the preparation of this material.

A new promising method for the synthesis of NASICON (Na 3 Zr 2 Si 2 PO 12 ) by pyrolysis of organic solutions has been developed. Sodium oleate, zirconyl oleate, tributyl phosphate, and tetraethoxysilane have been used as precursors. The molar ratios of the components of the mixture for the formation of NASICON have been established. The effect of sodium on the formation of the zirconium dioxide phase has been proven. A finely dispersed material with an average grain size of 0.2 µm has been obtained. Changes in morphology and composition depending on the time and temperature of firing the sample are studied. The results have been confirmed by X-ray powder diffraction and scanning electron microscopy. To refine the parameters of the crystal lattice, a full-profile analysis has been performed by the Rietveld method. The process of obtaining NASICON takes about 9 h, i.e. it is the least time consuming of all the alternative ways of synthesis. The advantages of this method are the possibility of lowering the sintering temperature, the absence of the need to control many parameters during synthesis, and minimizing the duration and multi-stage process. The method contributes to the development and production of more promising ion-substituted structures.

The results of a study of the opening of titanium-, boron- and tungsten-containing concentrates by NH4HF2, (NH4)2SO4 and a mixture of these reagents are presented. It has been shown that during solid-phase interaction with the indicated reagents, when heated to 200°C, fluorination of the components included in the concentrate occurs with the formation of simple and complex fluorides; a further increase in temperature leads to the formation of ammonium hydrosulfate NH4HSO4, which, when interacting with the formed fluorides, leads to their conversion into soluble double sulfates. The ways of extracting components of concentrates with obtaining commercially demanded compounds as commercial products are shown.

A new method for preparing Na1 + xZr2SixP3 – xO12 (0 x 3) based on pyrolysis of solution containing a mixture of organic components in rosin melt has been proposed. Effect of superstoichiometric amounts of sodium and phosphorus on the phase composition of synthesis products has been proved. It has been found that precursor for the sample of maximal purity of phase composition is prepared at molar ratio Na : Zr : Si : P = (1.15 + x) : 2 : x : (y – x), where y = 3 (1.20 + x)/(1 + x). Precursor calcination temperature is 1000°C. Different NASICON compositions without crystalline admixtures have been obtained in the range 1.5 ≤ x ≤ 2.12. The prepared samples have been studied by X-ray powder diffraction and scanning electron microscopy. The disclosed method of synthesis is promising for the preparation of NASICON as both bulk materials and thin layer coatings.

The interaction of gold-containing rock and titanium-containing mineral raw materials with a mixture of ammonium hydrodifluoride NH 4 HF 2 and ammonium sulfate (NH 4 ) 2 SO 4 at temperatures below 430°C has been studied. A comparative analysis showed that the use of a mixture of NH 4 HF 2 and (NH 4 ) 2 SO 4 allows more complete winning of mineral raw materials compared to the use of ammonium hydrodifluoride alone. The mixture of NH 4 HF 2 and (NH 4 ) 2 SO 4 is recommended as a new promising reagent for the decomposition of rocks and mineral raw materials for complete extraction of the product into solution during water leaching.

Some results of using the extraction pyrolytic method for the synthesis of efficient luminophores on the basis europium and terbium oxides, oxysulfides, phosphates, niobates, tantalates, and borates, including compounds doped with other ions, are presented. The method makes it possible to introduce dopants with a high precision in a broad range of ratios between elements and, varying the pyrolysis process temperature and time, to control the composition, particle size, structure, and properties of luminophores. The luminescent characteristics of luminophores are estimated from their luminescence excitation and luminescence spectra. The synthesized luminophores of different composition exhibit intensive luminescence in the region of 550–800 nm.

Представлены разработки новых биоактивных керамических мате-риалов на основе диоксида циркония, которые имеют потенциальное применение в ортопедической хирургии в качестве имплантов. Материалы способны поддерживать регенерацию костных тканей и участвовать в процессе интеграции нативной ткани в имплант. Текстура и свойства поверхности созданной керамики может обеспечить ее длительную и стабильную фиксацию в тканях пациента.

In order to expand the list of materials suitable for the treatment of malignant neoplasms, a composite glass-ceramic has been obtained, consisting of calcium tantalate microcrystals enclosed in a glass matrix. The material has been studied in vivo. The composite is a radiomodifier; it improves the visualization of the irradiation zone, does not pose a threat of radioactive contamination of the body, and reduces the likelihood of radiation complications in healthy tissues. It has been established that due to the two-phase composition of glass ceramics, CaTa2O6 microcrystals are able to linger in tissues at the injection site and provide more effective radiation therapy. The radiosensitization properties of the material increase the efficiency of a single dose of radiation. The created glass ceramics is a promising material for the treatment of patients in need of radiotherapy.

Люминофоры на основе оксидов, оксисульфидов, фосфатов, ниобатов, танталатов и боратов редкоземельных и редких элементов синтезированы низкотемпературным экстракционно-пиролитическим методом. Рассмотрены спектры возбуждения люминесценции и спектры люминесценции люминофоров. Оценено влияние допирующих добавок на спектрально-люминесцентные свойства – характер спектров и интегральную интенсивность люминесценции ионов европия в соединениях.