Vol 72, No 11-12 (2016)

Medicine needs means for targeted delivery of pharmaceutical preparations. Microspheres have a wide range of applications in medicine and are used as means for delivering pharmaceutical preparations and radiation to internal organs in the human body. Methods of obtaining and using glass microspheres, including radioactive ones, for medical purposes are described in this review.

Vibrational spectroscopy is used to show that the effect of adding titanium to K₂O–B₂O₃–SiO₂ glasses differing by the ratio of the boron and alkali metal contents is different. This result reflects the change in the structural role of titanium in the glass and is important for evaluating the influence of titanium additions on the properties of alkali borosilicate glass in the process of improving the glassy matrix materials used for the immobilization of radwastes.

The possibility of obtaining lithium molybdate Li₂MoO₄ crystals from water solutions activated by low-frequency oscillations of a chemically inert body is examined. It is shown that the activation of the solution increases the equilibrium solubility of Li₂MoO₄ in the water solution in the temperature interval 25 – 28°C. It is found that the activation of a solution affects the form of the faceting of the crystals grown and the surface morphology of the faces. It is shown that activation of the solution decreases the inclusions of water in the crystals and improves the surface quality of the growing crystal.

A high-efficiency wall ceramic based on expanded perlite, opoka, and ground glass has been obtained. It is shown that solid ceramic brick (average density 925 kg/m³ and strength in compression 13.5 MPa) for low-rise structures can be produced

It is shown that modern high-porosity insulation material can be obtained on the basis of silicon dioxide. The most significant parameters influencing the formation of a porous structure of gels obtained from alkoxides by the sol–gel method are determined by means of factor analysis.

Nondestructive regimes of laser high-temperature annealing of KO-3 optical ceramic by CO₂ laser radiation are determined for an isotropic plate within the framework of a quasistatic uncoupled problem. It is shown that nondestructive regimes obtain only for sufficiently long-time irradiation and low power density of the laser radiation. The adequacy of the computational model is checked experimentally.

A three-component ceramic material is obtained in the system ZrO₂–SrTiO₃–BiScO₃; its phase composition and microstructure particularities are determined; and, the temperature dependence of the conductivity is studied. It is found that at room temperature the material consists of a cubic phase with space symmetry group Fm3m, corresponding to the cubic modification of zirconium dioxide, and a solid solution consisting of nonpolar cubic phase with Pm3m symmetry and polar tetragonal phase with P4mm symmetry characteristic for a two-component SrTiO₃–BiScO₃. An investigation of the microstructure and elemental composition of samples by means of scanning electron microscopy confirms the presence of these phases. It is found that above the temperature about 750 K the conductivity of the experimental samples increases significantly.

A model of the ordered packing structure of free-flowing media (spheres) with cells in the form of conventionally cut-out (quasifaceted) parallelepipeds, whose vertices are located at the center of eight neighboring granules- spheres, is studied. Power-law and exponential dependences of the coordination number of the granules- spheres on the packing density γ and porosity ω of the medium are presented. More precise linear and nonlinear dependences are presented for comparatively narrow ranges of γ and ω which are characteristic for filling-media.

Synthesis of compositions and preparation/deposition technologies are shown to be possible for gas-tight, isotropic coatings for protecting structural steels, used in the manufacture of hydrogen power facilities, in order to increase their stability in hydrogen and reduce the hydrogen permeability at temperatures to 600°C.