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The study of structure of nanocomposite material based on porous glass with 7 nm average pore diameter filled by sodium nitrate from the melt under pressure has been carried out by synchrotron radiation diffraction upon heating and cooling. The temperature evolution of the elastic peak lineshapes corresponding to the sodium nitrate structure has been analyzed, and it is shown, that in the "virgin" sample there are two types of nanoparticles with dendrite spatial organization and with fundamentally different characteristic sizes. The temperature dependences of the critical index β(T) for the structural transition in sodium nitrate have been obtained, and the crossover in this dependence for nanoparticles with a characteristic size of about 20 nm has been found at T∗ ∼ 445 K both upon heating and cooling. The temperatures of the structure and "melting – crystallization" phase transitions observed in this nanocomposite have been determined. [ABSTRACT FROM AUTHOR]

The temperature evolution of the crystal structure and dielectric response of a nanocomposite based on porous glasses with an average pore diameter of 7 nm and embedded sodium nitrate in the temperature range of 300–600 K have been studied on heating. The temperature dependences of the amplitudes of thermal vibrations of ions in sodium nitrate nanoparticles are obtained, and the activation energies of sodium hopping conductivity in these nanocomposite materials are determined. The results obtained allow us to state that it is the sharp increase in thermal vibrations that leads to the appearance of the previously observed crossover in the temperature dependence of the order parameter of the structural transition in sodium nitrate nanoparticles at T* ∼455 K and to a decrease in the activation energy of sodium ions hopping conductivity on heating above T*. • Unusual order parameter temperature dependence in NaNO3 nanoparticles. • Appearance of a crossover in this dependence near T* ∼450 K. • A sharp growth of ion thermal vibrations above T*. • Increase of sodium hopping conductivity when approaching the crossover. • Significant reduction of the structural transition temperature compared to bulk NaNO3. [ABSTRACT FROM AUTHOR]

Abstract Granulometric test and morphological analysis of the bentonite particles were performed using laser diffraction and low-temperature nitrogen adsorption–desorption techniques. Bentonite particles were immobilized into the hydroxyethyl cellulose matrix by mechanical dispersion, and composite films were obtained. The effect of concentration of the filling agent on structure and tensile properties of composites was revealed. Data on the nature of interaction between hydroxyethyl cellulose and bentonite after the modification of polymer were obtained by IR spectroscopy. It was found that the hydroxyethyl cellulose/bentonite composite films showed an antimicrobial effect against Escherichia coli and Staphylococcus aureus bacteria, as well against fungi association. [ABSTRACT FROM AUTHOR]

A single crystal of Nd5Mo3O16 with lead partly substituting for neodymium, which has a fluorite-like structure, was studied by precision X-ray diffraction, high-resolution transmission microscopy and EDX microanalysis. The crystal structure is determined in the space group . It was found that the Pb atoms substitute in part for Nd atoms in the structure and are located in the vicinity of Nd2 positions. Partial substitutions of Mo cations for Nd positions and of Nd for Mo positions in crystals of the Ln5Mo3O16 oxide family are corroborated by X-ray diffraction for the first time. The first experimental verification of the location of an additional oxygen ion in the voids abutting MoO4 tetrahedra was obtained. [ABSTRACT FROM AUTHOR]