quantum-chemical calculation

The inhibition effect of the grape pomace extract during the early stage of steel corrosion under adsorbed thin electrolyte layers was investigated. The present study was carried out to identify the components present in the 2-propanol grape pomace extract by GC-MS analysis. Gravimetric, electrochemical impedance spectroscopy, potentiodynamic polarization, scanning electron microscopy, and FTIR techniques were used to study the corrosion inhibitive. Polarization measurements have indicated that these green inhibitors acted through mixed type inhibition.

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.  

Mechanisms of wastewater purification from surface-active substances and of sulphuric acid dissolution of iron-containing sludge formed during the previous process have been established. Kinetic regularities of metal-containing sludge dissolution in sulphuric acid have been investigated. Kinetic equation which adequately presents the experimental data has been proposed; constants of this kinetic equation have been calculated.

Energies of formation, enthalpies, and entropies of the conformers of 1-(carboxy)-1-(N-methylamide)-2-(3',5'-di-tert-butyl)-4-hydroxyphenyl)-propionic acid and sodium and potassium 1-(carboxy)-1-(N-methylamide)-2-(3',5'-di-tert-butyl)-4-hydroxyphenyl)-propionates are calculated by quantum-chemical methods in the PM6 approximation. A doubling of signals in the 1H NMR spectrum of the first conformer is observed, which merge into singlets when the compound is heated.

The research revealed that Fenton reagent is to be utilized to remove the dye (active bright orange CS/5K) from industrial sewage. Hypercube Hyperchem Professional v8.01 software (trial) was used to carry out the quantum-chemical calculation of colouring agent structure and heat energy. Based on the information from references and the received experimental data, the oxidation mechanism of colouring agent (active bright orange CS/5K) by photo-Fenton system has been introduced.