Physical and chemical stability and features of mizhfaznoy cooperation of materials is on the basis of powders of refractory nitridiv with the biological environments of organism

Abstract

Wetting processes of materials based on silicon nitride, aluminum nitride, and titanium nitride coarse (C) powders and powders obtained by plasma chemical synthesis (PCS) with distilled water, physiological solution, and human blood plasma have been investigated. It has been proved that the smaller limiting wetting angles in systems with physiological solution and blood plasma are connected with smaller values of surface tension for these media as compared with water, which is due to the presence of active protein compounds and salts in their composition. We have established the following sequence of activity of samples of refractory nitrides with respect to decreasing the limiting wetting angle: Si₃N₄ c – TiN c – AlN c – Si₃N₄ pcs – AlN pcs –TiN pcs. An investigation of the influence of the dispersity, structure, and character of the chemical bond in silicon nitride and aluminum nitride powders on the features of their interaction with inorganic and biological media of the human organism has been performed. It is shown that the predominantly covalent character of bond in α- and β-silicon nitride powders causes their stability in acid and neutral media. The interaction of aluminum nitride powders with the biological media proceeds by the ionic-adsorption mechanism. In this case, the fraction of the ionic bond in aluminum nitride molecules, i. e., the covalentionic character of the chemical bond, reduces the stability of AlN nanopowders in the biological and inorganic media as compared with that of Si₃N₄ powders. The phase compositions of the nanopowders of both nitrides after interaction with human blood plasma remain unchanged due to the presence of proteins, which form protective layers on the surface of powder nanoparticles and exert an inhibiting influence on hydrogenation reactions.