золь-гель процес

Methods of obtaining of magnesium-aluminate spinelpowders. Review

The main methods of synthesis of magnesium-aluminate spinel powder their features and advantages were analyzed. The character of the physicochemical interaction of components in theMgO–Al2O3 system physical and crystallographic characteristics and structural parameters of thecrystalline lattice of magnesium-aluminate spinel wereresearched. The synthesis conditions arepresented and qualitative comparison of the possibilities of synthesis methods in terms of theproperties of spinel powders are made.

Квантово-хімічний розрахунок структури тетраетоксисилану та кінетичних параметрів реакції його гідролізу

The paper is devoted to quantum-chemical calculation of tetraethoxysilane (TEOS) structure by different methods: РМ6, Hartree-Fock and DFT. PM6 method was found to be optimal. Kinetic parameters (activation energy and preexponential factor) of hydrolysis of TEOS molecule were evaluated using quantum-chemical calculation.  Key words: quantum-chemical calculation, PM6, sol-gel process, tetraethoxysilane, rate constant of hydrolysis.