卷 487, 编号 2 (2019)

New water-soluble nickel and cobalt complexes—sodium cobalt pectinate (PNaCo) and sodium nickel pectinate (PNaNi)—have been obtained from sodium pectinate with a salt formation extent of 35%, and their physicochemical properties have been studied. Antimicrobial activity of PNaCo and PNaNi against gram-positive and gram-negative bacteria and fungi has been shown.

A new 2-amino-4-ferrocenylthiophene-3-carbonitrile has been obtained by Gewald reaction, the compound has been converted into Schiff bases as precursors for new optoelectronic and magnetic materials. The structure of the prepared compounds has been established by elemental analysis, IR spectroscopy, and ¹H NMR.

A new method for synthesis of high-purity fine crystalline magnesium aluminate spinel (MgAl₂O₄) has been proposed by treating a mixture of finely divided MgO and aluminum hydroxide (Al(OH)₃) or oxyhydroxide (AlOOH) with aqueous fluid under supercritical conditions (T = 380–400°С, Р\(_{{{{{\text{H}}}_{{\text{2}}}}{\text{O}}}}\) = 22.8–23.0 MPa). It has been demonstrated that the formation of the magnesium aluminate spinel structure occurs by a solid state mechanism. The new method of synthesis makes it possible to control the size (from 20 nm to 5 µm) and shape (spherical, lamellar, or bipyramidal) of the synthesized magnesium aluminate spinel (MgAl₂O₄) by varying the reaction conditions.

Nanostructured island coatings composed of the low-temperature alumina modification were synthesized on the surface of macropores of hierarchically porous permeable monolithic nickel. The primary structural elements of the coating were determined to be hexagonal alumina nanoplates.

Reverse pressing under the active action of external friction force was theoretically analyzed based on the previously developed rheodynamic models of high-temperature SHS compaction. It was shown that, in this pressing method, external friction is a useful technological phenomenon, which allows one to reach a uniform density distribution in the bulk of the material of the workpiece. Analytical expressions for calculating the characteristic pressing time and the pressure distribution were obtained.