Problems of Chemistry and Chemical Technology

Obtaining of straw pulps by peracetic pulping method of delignification

The paper studies the influence of the basic technological parameters of obtaining straw fibrous semifinished products by the peracetic method of delignification. Using the method of full factorial experiment, we obtain the regression equations of producing straw fibrous semi-finished products. Furthermore, we determine main kinetic characteristics of the delignification process of wheat straw

Inhibition Efficiency Hop Cones

This study aims at evaluating the inhibition efficiency of two different hop cones and analyzing their adsorption properties on the surface of steel components that actually comprise hop cones. By employing weight loss and potentiodynamic polarization methods, we compare volatile fractions of “Aromatic” and “Bitter” hop cones. We analyze the adsorption ability on the surface of steel components that comprise hop cones using quantum-chemical calculations.

Thermo-Physical Properties and Specificity of of Nanocomposites Thermal Degradation Cured in Constant External Physical Fields

By using the methods of DSC, TGA-DTG analysis, we study nanocomposites composition EP– 3 % CdO and EP–3 % (CdO + PAn) cured under standard conditions in constant magnetic or electric fields. We show that these factors affect the segmental mobility of interstitial cross-linked polymer fragments and the spe-cific heat jump. The interaction of external magnetic field only with dipole mo-lecules of the sample EP–3 % CdO causes a partial change in its structure. Ana-lytical processing of DSC thermograms showed that introduction of the polyani-line (Pan) and CdO 3 % vol.

Structure Formation in Dispersions of Montmorillonite in the Presence of Quaternary Ammonium Salts

The aim is to study the influence of cationic surfactants – quaternary ammonium salts – for structure formation in montmorillonite suspensions by studying the rheological and colloidal-chemical properties of such systems. Relying on x-ray diffraction analysis we identify surfactant molecules close to a parallel position relative to the basal surface of mineral with the interlayer space of 1.6 nm. By using rheometry we obtain flow curves and corresponding values of boundary shear stress for dispersions of montmorillonite in the presence of cationic surfactants.

Water Chemistry and Mathematical Modeling of the Second Circuit of the NPP with PWR-1000

This article discusses the current state of issues of the water chemistry support at operating NPP with the pressurized water reactor with determined capacity of 1000 MW (PWR-1000). We provide an overview of technological features of the power unit with PWR-1000. Methods and tools to ensure the water chemistry of the second circuit of the NPP are analyzed. Furthermore, we establish that performance of the normalized quality indicators of feed water can not completely eliminate deposits formation on heating surfaces.

The Impact of the Composition of Aqueous-Alcohol Dispersion on Electrokinetic and Rheological Properties of Composite Coal-Water Suspensions

In this work, we obtain sedimentary resistant aqueous suspensions of coal containing waste products of alcohol production – fusel oil and also wastewater with organic compounds. To this end, we study influence of alcohol aqueous solutions and modification of coal surface under the impact of anionic polyelectrolites on electrokinetics and rheological properties of coal aqueous suspensions. The boll mill technique is used to make dispersions, while electrochemical methods and viscosimetry are utilized in the research.

Exploitation Propperties of Cellular Concrete with Modificated Surface

The purpose of work consists in development of impregnating with compositions on the basis of siliconorganic matters of modified by thermoplastic polymers for the impregnation of cellular concrete. Treatment the prepared compositions allow to promote operating properties of cellular concrete wares. The decision of this task was arrived by research of influence of surface retrofitting of cellular concrete wares by impregnating with compositions of different composition and concentration.

Microfiltration Cleaning from Fe3+ Ions of Scourages Deferrization Stations

Currently, baromembrans methods based on polymeric membranes are used for water treatment from Fe3+ ions. However, such membranesare destroyed under the impact of hydroxo-complexes of Fe3+ ions contained in water. Therefore, we do the research into basic regularities of model scourages cleaning from Fe3+ ions using microfiltrations titanic tubular membranes that are more persistent and have more long-term operating life than polymeric ones.

The Photocatalysis Mechanism on TiO2 Surface

We discuss the mechanism of heterogeneous photocatalysis (formation of electron-hole pairs) on the TiO2 surface (initiated by ultraviolet radiation) as well as the stage of the photocatalytic process. As a result, we determine that to increase the efficiency of the photocatalytic process in the visible light range it is necessary to reduce the band gap of catalyst based titanium oxide (IV).

Calculation of Thermodynamic Properties of Graphite and Grapheme Based on Spectroscopic and Elastic Characteristics

In this paper, we calculate the low temperature (0–300 К) heat capacity, enthalpy, entropy and reduced Gibbs energy of graphite and graphene. Specifically, we calculate the temperature dependencies of heat capacity using literature sources on phonon spectrums of materials and elastic properties of graphite as input values. We show that thermodynamic characteristics of graphene substantially exceed those for graphite. Specifically, we explain these differences by features of the graphene phonon spectrum.