Problems of Chemistry and Chemical Technology

Remediation of the U(VI) Ions from Waters Using Organic Clays

This paper studies characteristics of sorption of anion and cation forms of uranium (VI), as well as uranium carbonate complexes. By modifying the natural clay mineral montmorillonite by cationic surfactant, we obtain sorbents for uranium remediation from waters. Relying on the methods of XRay diffraction, IR-spectroscopy, turbidimetry, and adsoption, we determine sorptive properties of the natural and modified samples. Furthermore, we prove the effectiveness of using these methods for uranium remediation from waters.

Substantiation of Processes Efficiency Methodology Assessment of Plant Material Delignification

The paper develops the methodology for determining the most efficient processes delignification of plant material to obtain pulps, suitable for use in various industries. Experimental data and calculated characteristics of obtained pulps from one representative non-wood plant raw material – wheat straw by different methods of delignification: soda, neutral sulphite, bisulphite, acetic, ester, ammonia-sulphite-alcohol, two-stage alcoholic alkali, peracetic, alkaline-sulphite-alcohol.

The Physical and chemical properties of composite systems with nonconductive oxide fillers

In this paper, we analyze the body of scientific data on the effect of disperse filling of salt systems by oxide materials. Emphasized here is the nano-sized TiO2 as a disperse filler. The experimental data shows that the 5,9 V electrochemical window of pure and filled ionic liquid PYR14TFSI with the increased (to 30 %) electrical conductivity is stable. Such windows allow PYR14TFSI filled by nano-sized TiO2 to be used with very strong reducing and oxidizing electrode agents, yielding high cell voltage.

Quantum-Chemical Modelling of Functionalized Silica Surface

Based on the quantum chemical modeling of silica surface (DFT (B3LYP/6-31G (d, p))) functionalized with phosphorus- and thiourea-containing groups [≡Si(CH2)2P(O)(OC2H5)2, ≡Si(CH2)2P(O)OH2 and ≡Si(CH2)3NHC(S) NHC2H5], we show that hydrogen bonds can be formed between donor and silanol groups in the T2 structural unit both in the presence and absence of water molecule. The functionalized xerogel surface was modeled by (HO)2Si(OH)R′ fragments, where R′  –(CH2)2P(O)(OC2H5)2, –(CH2)2P(O)(OH)2 or –(CH2)3NHC(S)NHC2H5.

The Dependence of Integral Capacity of Double-Layer Electric Capacitor on Potential

The paper studies the dependence of supercapacitor’s integral capacity on potential. We prove that the capacity as a linear function depends on the potential. We also show that the neglect of the potential’s influence on supercapacitor capacity can result in significant failures at calculation of energy intensity.

The Electrochemical Sensor of Carbon Dioxide with Manganese Dioxide Working Electrode

Relying on the electrochemical cell with the manganese dioxide gas-diffusion electrode, we develop the titanium-based galvanic-type sensor of carbon dioxide. Furthermore, we define the effect of such factors as the amount of manganese dioxide on the working electrode, the pH of solution in the sensor, the magnitude of diffusion resistance (the size of gas diffusion window), the internal resistance of electrochemical cell and the resistance of load resistor on the metrological characteristics of the sensor (the normalization of the current signal of sensor and the transient time 0,9).

Development of Environmentally Safe Technical Detergent

This study demonstrates the possibility of introducing BG-10 surfactant into the technical detergent. We do the research into BG-10–Ferrum (III), BG-10–МЕА–Ferrum (III), BG-10–МЕА–Leik–Ferrum (III) as a pollution ingredient interaction that can cause redeposition on the surface. Finally, we determine the corrosion activity and foaming ability of BG-10.

The Investigation of Calcium Carbonate Precipitation with Simultaneous Hydrolysis Process of Carbamide in Aqueous Solutions of Calcium Chloryede

We reveal that the tiff with hexagonal particles is formed at the controllable slow precipitation from calcium chloride solution with carbamide. We also figure out the kinetic characteristics of the reaction: the velocity constants at various temperatures, the reaction order and the activation energy.

The Effect of Temperature Change of the Solvent Properties on the Termodynamic Characteristics of Chemical Equilibrium in Solutions

This paper proposes a novel approach to dividing thermodynamic characteristics of the chemical equilibrium in solutions, calculated from the polytherm of equilibrium constants. The first component of the equilibrium constant characterizes the process; the second one is caused by the temperature change of the solvent properties. This approach suggests that the extreme on polytherm equilibrium constants appear not because of the change in the nature of the process in the solution, but because of the temperature variation of the solvent permittivity.

The Heat Resistance of Diffusion Chromosilicide Coatings Applied on a Carbon Stells

The paper studies heat resistance and the mechanism of high-temperature oxidation of chromosilicide diffusion coatings applied on a surface of carbon steels by a gas method. We define the factors of influence on the process of high-temperature steels oxidation with the obtained coatings. The interrelation between the composition, the structure of diffusion layers and the speed of high-temperature oxidation is established. We show that the obtained coatings have a high heat resistance in an interval of temperatures between 623–1273 K.