L. P. Borilo

Methyl tert-butyl ether as a new solvent for the preparation of SiO2–TiO2 binary aerogels

SiO2–TiO2 binary aerogels have been synthesized for the first time using methyl tert-butyl ether as supercritical fluid. It has been shown that the aerogels prepared in methyl tert-butyl ether and isopropanol contain nanocrystalline anatase and that amorphous SiO2–TiO2 aerogels with a homogeneous distribution of their components can be obtained in CO2. A considerable contribution to the large specific surface area of the aerogels is made by micropores, especially when supercritical drying is carried out in CO2 and isopropanol.

Synthesis of gadolinium hydroxo nitrate under microwave-hydrothermal treatment conditions

A new effective method for the synthesis of the layered hydroxo compounds of gadolinium based on the microwave-hydrothermal treatment of gadolinium salt solutions in the presence of hexamethylenetetramine was proposed. The effect of synthesis conditions on the phase composition and the micromorphology of the synthesis products was analyzed. It was found that an increase in the temperature and duration of the microwave-hydrothermal treatment led to the disordering of the layered structure of the layered hydroxo compounds of gadolinium and to an increase in the concentration of carbonate groups in the resulting layered hydroxo compounds of gadolinium.

Study of Biological Properties of Thin-Film Materials on the Basis of the SIO2–P2O5–СaO System

Thin films were obtained from film-forming solutions by the sol-gel method on the basis of the SiO2-P2O5-СаO system. Thin films were produced on the single-crystal silicon substrates (model substrate) by extraction at a velocity of 5 mm/s following by heat treatment at a temperature of 60°С for 20 minutes and at a temperature of 600°С for 1 hour. During the experiment it was established that film-forming solutions are usable only for 2 to 7 days from the moment of preparation. Using thermal and infra-red – spectroscopic analysis main stages of oxide system formation were retraced. According to data from x-ray phase analysis phases CaClH2PO4∙H2O, Ca(H2PO4)2∙H2O, CaHPO4∙2H2O, Ca2SiO4∙H2O, Ca5(PO4)3Cl. On the supporter’s surface a homogeneous film coating with quite equally spaced crystal-like formations with the diameter of 10-11 microns at the distance of 1-30 microns was formed. Phase composition, surface properties and biological activity of the synthesized materials were investigated. XRD results indicated that after being immersed into the SBF, hydroxylapatite, wollastonite, and chlorapatite were formed on the samples’ surfaces, which was important for practical applications

Film-Forming Capacity of Sn(II), Zr(IV), and Hf(IV) Acetylacetonates

Zr(acac)4, Hf(acac)4, and SnHacacCl2 · 2H2O were prepared in the solid state and in enthanol solutions. The film-forming capacity and thermal stability of these compounds were studied. Films of ZrO2, HfO2, and SnO2 were prepared from film-forming solutions of the corresponding acetylacetonates.

Synthesis of manganese dioxide by homogeneous hydrolysis in the presence of melamine

A new selective method for the synthesis of nanocrystalline manganese dioxide (α-, β-, and γ-MnO2) based on the reaction of potassium permanganate with 2,4,6-triamino-1,3,5-triazine (melamine) under hydrothermal conditions has been proposed. Effect of synthesis conditions on the phase composition of the products has been revealed. A new manganese-containing phase with layered structure has been prepared.

Synthesis and properties of bioactive thin-film materials based on the SiO2–P2O5–СаO and SiO2–P2O5–CaO–TiO2 systems

Thin films based on the SiO2–P2O5–СаO and SiO2–P2O5–CaO–TiO2 systems have been grown from film-forming solutions by a sol–gel process. We have studied the physicochemical processes underlying film growth and the phase composition, structure, and biological activity of the materials obtained. The addition of titanium oxide has been shown to improve the biological activity of the materials.

The synthesis and properties of thin films based on double oxide system SiO2-ZrO2

The main physical and chemical processes involved in the preparation of SiO2-ZrO2 thin films from film-forming solutions based on zirconium oxochloride ZrOCl2·8H2O, tetraethoxysilane Si(C2H5O)4, and ethanol were studied. The phase composition, structure and physical and chemical properties of the films were determined and the diagram composition — property was constructed.

Synthesis and properties of materials based on SiO2-CaO-P2O5-TiO2 for biomedical usage

Thin films of film-forming solutions based on calcium chloride, tetraethoxysilane, tetrabutoxytitanium, and phosphoric acid have been synthesized in the paper. Thin films were obtained from film-forming solutions on single-crystal silicon substrates (model substrate) by centrifugation at a rotation speed of 3000 revolutions/min. Followed by heat treatment at 60 ° C for 20 minutes and at 600 and 800 °C for 1 hour. The solutions are suitable for obtaining uniform films up to 5 days. The properties of the material were investigated by the methods of infrared spectroscopy, X-ray phase analysis, and thermal analysis. Biological activity was studied under artificial conditions in the simulation body fluid medium. With an increase in the weight content of titanium oxide in the system up to 10%, the bioactivity of the material increases.

SiO2–TiO2 binary aerogels: Synthesis in new supercritical fluids and study of thermal stability

A comparative analysis of properties of SiO2–TiO2 binary aerogels prepared by supercritical drying using different supercritical fluids (isopropanol, hexafluoroisopropanol, methyl tert-butyl ether, and CO2) has been performed. The use of different supercritical fluids allows preparation of both homogeneous amorphous SiO2–TiO2 binary aerogels (by supercritical drying in hexafluoroisopropanol and CO2) and composite aerogels containing nanocrystalline anatase (by supercritical drying in isopropanol and methyl tert-butyl ether). The thermal treatment of the aerogels at temperatures up to 600°C does not lead to considerable change in the porous structure and phase composition of the aerogels.

Properties of calcium phosphate thin film biomaterials with the addition of titanium oxide

Thin films were synthesized by sol-gel method from alcohol film forming solutions (FFS) based on tetraethoxysilane, phosphoric acid, calcium chloride. Concentration of tetrabutoxytitanium was 0.4 and 0.3 M. Thin films were produced on substrates of single crystal silicon (model substrate) by spin-coating with a centrifuge speed of 3000 rev/min, followed by heat treatment at 60 °C for 20 minutes and at 600 °C for 1 h. During the experiment it was found that film with uniform surface may be got on the fifth day after preparation of the solution with a concentration of Ti4+ 0.3 M. For homogeneous material requires heat treatment at 800 °C. The highest bioactivity was observed in the films based on film-forming solution with a concentration of Ti4+ 0.3 M.