Ceramics Based on Nano-Modified Alumino-Silicates

The paper considers the formulation of nanomodification of alumino-silicate raw materials, in order to obtain ceramic materials, based on it, by various molding methods with an increased strength and other operational properties. Studies of the dependence of the compressive strength on the type and concentration of aluminum and silicon oxide nanoparticles, their influence on the granulo-metric composition and microstructure of alumino-silicate powders, based on alkaline earth bentonite, are presented. It is shown that the addition of oxide nanoparticles in small concentrations leads to a decrease in the average particle size, aggregated structural elements of bentonite and their redistribution, and changes in morphological parameters (the shape of micro-aggregates and aggregates, pores), which increases the strength of raw materials and, as a result, burnt products.

Microencapsulation of Thermochromic Material by Silicon Oxide Nanoparticles

This study is mainly focused on the fabrication of SiO2 as an inorganic shell material encapsulated an organic thermochromic (TC) core material comprises of either the (i) three-component as-synthesized blue dyes [BDTCM@SiO2] or (ii) off-the-shelf (commercial) black dyes [CDTCM@SiO2]. Both the SiO2 encapsulated thermochromic systems have successfully demonstrated the color transition at around 31 °C. For the three-component thermochromic microcapsules, we have used the crystal violet lactone (CVL) as a leuco dye, bisphenol-A (BPA) as a color developer, and 1-tetradecanol (TD) as a solvent. Different ratios of the thermochromic dye and the metal oxide were prepared to examine the effect of the core@shell ratio on the microstructural and thermal properties of the encapsulated microcapsules. The mean particles sizes of the BDTCM@SiO2 are below 100 nm, whereas, the CDTCM@SiO2 samples exhibited the mean particle sizes varied in a range of 100-1000 nm. The endothermic phase transition due to melting and in general, the thermal stabilities of these SiO2 encapsulated TCMs have been explored for the purpose of deploying these systems for thermal energy savings or storage applications.

Исследование влияния добавки наночастиц гидрофобного оксида кремния на коллоидную устойчивость обратных эмульсий

The results of experimental studies of the effect of the addition of silicon oxide nanoparticles on the stability of inverse emulsions based on mineral oils are presented. The concentration of nanoparticles in the emulsion was varied from 0.25 to 2 wt%. The following ratios of the volume fractions of the hydrocarbon phase and water were investigated: 70/30, 80/20, 90/10. Several types of emulsifiers have been considered. It has been shown that, even at low concentrations, hydrophobic SiO2 nanoparticles significantly improve the stability of inverse emulsions. Destabilization rate of the emulsion upon addition of 2 wt%. of nanoparticles decreases 1.7 times.

Повышение эффективности полимерного нанокомпозита для формирования фотонных структур методом оптической записи

In this work, the conditions for optimizing an optical recording material based on photosensitive acrylate-urethane nanocomposites with silicon oxide nanoparticles, for efficient Bragg gratings recording by multibeam interference method is presented. It was shown that the choice of the most effective monomers and their concentrations in the nanocomposite which depends on their structure and polymerization rate, followed by determination of the optimal recording radiation intensity for the given composition, makes it possible to adjust the conditions for component diffusion and redistribution, and hence, the formation of regions with different refractive indices in the recording medium. These results can be useful for creating complex 2D and 3D photonic structures based on the targeted modification of photosensitive polymer nanocomposites with different properties (luminescent, nonlinear optical, etc.).

Экспериментальное исследование влияния добавки наночастиц оксида кремния на характеристики смачиваемости нефтью горной породы

The results of experimental studies of interfacial tension and surface wettability in the nanoscale suspension/oil/rock system were presented. For the first time, the influence of the concentration and size of silicon oxide nanoparticles on the interfacial tension coefficient and the wetting angle was systematically studied. Wide ranges of nanoparticle mass concentrations(from 0 to 1wt.%)and their average sizes(from 5 to 50 nm) were considered. It is established that the use of nanosuspensions allows to radically change the wettability of rock with oil. This effect is significantly dependent on the concentration and size of nanoparticles.