卷 43, 编号 5 (2017)

It is established that the time dependence of the intensity of the polarized component of visible light scattering by boron oxide under the influence of a constant temperature gradient is characterized by the same features as in the case of temperature variation. Based on this analogy, the relaxation times of the process of increasing the intensity in a nonuniform temperature field for different temperature intervals are determined. The activation energy of the process of increasing the intensity for different experimental conditions is calculated using the Arrhenius equation, and it is found that the calculated activation energy values are in satisfactory agreement with each other and with the data of other studies. The uniform behavior of the time dependence of the intensity of visible light scattering and close activation energy values point to common physical reasons for the structural changes occurring on the boron oxide structure approaching the equilibrium and stationary states.

The structure modification in the bulk of plates of photochromic porous glass (PCPG) containing 0.28 wt % Ag₂O under the action of laser irradiation of a near IR-range with a power density of 0.6–1.9 MW/cm² and irradiation duration of 5–20 s is carried out. Locally modified structure regions are composed of the central and edge parts with a different content of silver nanoclusters and different density of the porous matrix. It is found that the size of the modified regions is much larger than the size of the focused laser beam, which can be associated with the thermophysical peculiarities of the material and the conditions of its laser-induced heating. The dynamics of the variation in the size of the modified region and its parts depending on the duration of the irradiation are studied.

To obtain ultra-optical property in glasses, as the basis for photonic applications, the glass forming region of TiO₂–Bi₂O₃–PbO system was investigated and determined by melting series of compositions in the system. The glass-forming boundary region was defined. The best compositions for glass formation were found to be around the eutectic and peritectic regions in the corresponding phase diagram. Generally, stability increased with the addition of TiO₂, acting as a conditional glass former, to a maximum of 15TiO₂ mol %. Replacing PbO with Bi₂O₃ in the glass worsened the stability, due to the increase of heavy cation Bi^3– in the glass structure. Finally, the refractive index and dispersion of some stable glasses were measured, which were as high as 2.435 and 10.2, respectively.

A method based on the hyperbolic mass transfer equation for processing the experimental data on the study of the diffusion kinetics in solid–reagent systems based on the delay of diffusion fluxes is proposed. Examples of calculating diffusion processes in metals are given.

The sol-gel technique has been utilized for the preparation of sorbent glass material incorporated with the ligand 2,2'-(imidazolidine-1,3-diylbis (methylene))bis(3,5-di-tert-butylphenol). Two procedures were used for the synthesis of the silica based material: (i) one step process under acidic conditions, (ii). A two steps procedure, using an acidic catalyst for the hydrolysis stage, and condensation of the silanol groups under basic conditions. The preparation conditions affect the morphological properties of the matrices and thus their sorption properties. The efficiency of Cu²⁺, Ni²⁺ and Cd²⁺ removal from aqueous solutions have been studied using batch experiments.

A series of protic alkanolammonium ionic liquids (ILs) based on triethanolammonium salts (protatranes) of biologically active carboxylic acids (cinnamic, benzoic, oxalic, malonic, succinic, salicylic, and citric acids) is synthesized and characterized. Their biological activity against the Rhizopus oryzae F-814 fungus is studied. The presence of ionic liquids in a culture medium gives rise to the biomass of the fungus growing by 8 to 24%, depending on the salt concentration and its composition.

The results of studying the thermal behavior of natural boron albite–reedmergnerite NaBSi₃O₈ and aqueous boricilicate–searlesite NaBSi₂O₅(OH)₂ obtained by the method of hydrothermal synthesis are presented. In the investigated temperature range, reedmergnerite (30–780°C) does not undergo phase transformations. Thermal expansion is sharply anisotropic, which is a characteristic feature of the expansion of feldspars. Aqueous borosilicate searlesite (25–750°C) is amorphized above 400°C as a result of dehydration and cristobalite crystallizes from the amorphous phase. The expansion of searlesite is relatively isotropic.

Elemental silver incorporated into thin glass-like gelatin films by the reprecipitation of elemental silver initially contained in them is studied by the methods of X-ray diffraction analysis and scanning electron microscopy. For the reprecipitation, silver undergoes a redox process by the following scheme: Ag → AgHal → Ag. It is shown that silver particles have a size of 20 to 30 nm in films and 80 to 100 nm when separated from films.

Leaching is considered as a means of reducing the alkalinity of glass powders produced from waste container glass and employed as additives to portland cement. The temperature of a leaching agent is established to be a key factor affecting the efficiency of the procedure. Also, for optimal leaching, the glass powder needs to be exposed only once to hot (close to boiling) water—a leaching agent—and only for a short period.

The effect of the relative volume of the conducting phase on the electroconductivity of phase-separated glasses in the ternary system Na₂O–B₂O₃–SiO₂, whose compositions are on the same glass transition isotherm at 550°C, is investigated. It is demonstrated that the electroconductivity of phase-separated sodium borosilicate glasses does not depend on the relative volume of the conducting phase (within the limits from 0.3 to 0.9) under the condition that its composition invariable.