Vol 54, No 4 (2018)

The influence of nickel sulfate additives to acid and basic electrolytes for microarc oxidation on the structure, composition, and properties of coatings formed on VT1-0 titanium were studied to produce poorly soluble titanium anodes. We established the possibility of incorporating nickel (nickel oxide) into the composition of coatings. X-ray diffraction analysis showed that the coatings contained nickel oxide β-NiO with a cubic lattice, TiO₂ in the form of rutile, and SiO₂ in the form of high-temperature β-cristobalite. The maximum thickness and nickel content in the surface layer and the minimum values of both the anodic dissolution currents and the electrical strength were obtained for the coatings formed in silicate-alkali (3 g/L KOH + 4.5 g/L Na₂SiO₃) electrolyte with the addition of 1 g/L of nickel sulfate NiSO₄.

We have obtained polypropylene-based (PP) specimens of polymer composites with various volume fractions of binary compound based on cadmium sulfide and zinc sulfide (CdS/ZnS). Their photothermoluminescence, photostimulated by UV exposure, was studied before and after exposure to γ-radiation. The photothermoluminescence (PTL) method revealed an increased concentration of local levels in the range of 500–600 nm of the semiconductor loading agent and in the phase-boundary layer of the polymer-loading agent due to impact of γ-radiation with doses up to 100 kGy. It was demonstrated that composites with the composition PP–(CdS/ZnS) 90 (10 vol %) are characterized by an intensification of relaxation processes at a temperature 300 K, which can be regarded as an improvement in the performance properties of the obtained composites. The radiothermoluminescence (RTL) method revealed an increase in the intensity of the RTL and PTL peaks due to introduction of binary CdS/ZnS compounds into the PP.

Graphene oxide (GO) is synthesized from commercially available graphite powder. The prepared GO is converted to reduced graphene oxide (rGO) by chemical reduction using sodium borohydride and sodium hydroxide. The rGO is characterized via X-ray diffraction, Raman spectroscopy and scanning electron microscopy. Conducting polymer–polyaniline, was prepared by oxidative polymerization in an electrolyte- hydrochloric acid and using ammonium persulphate as oxidant. The structure and doping of polyaniline were studied by Fourier-transform infrared spectroscopy and ultra-violet visible spectroscopy. To enhance the conductivity of the rGO, the conducting polymer mixed with rGO and rGO/Conducting polymer composites were prepared. The composite was characterized by cyclic voltammetry, AC impedance spectroscopy. A symmetrical supercapacitor (SC) has been fabricated based on rGO/PANI composites. The prepared composites were shown specific capacitance of 72 F g^–1 at 2 mV s^–1.

An expression is derived that relates the frequency of ring capillary and gravitational waves on the surface of the conducting liquid in an external uniform electrostatic field to the physical parameters and an analog of the wavenumber. It is shown that the obtained expression formally has the same appearance as the dispersion equation for plane waves; however, in the case under study, the wavenumber as a characteristic of ring waves has no sense due to the undefined concept of wavelength. The paper considers the possibility of attaining an electric discharge from the surface of the liquid charged in the external electrostatic field, when drops of the same liquid are falling on it.

The influence of different impurities on the kinetics of electronic processes in n-Ge single crystals is investigated. A substantial decrease in the charge carrier mobility in the region of predominantly impurity scattering (at 77 K) in n-Ge crystals, as well as in germanium crystals doped with the rareearth elements, is detected, and this effect is explained.

The paper deals with the both theoretical and experimental justifications of the formation of doubly charged ions (M⁺⁺) of several elements mass spectrometry with inductively coupled plasma (ICP-MS). The efficiency of the formation of both singly and doubly charged ions with the lowest value of the second ionization potential was shown using the Saha equation and thermodynamic modeling. The results of theoretical and experimental studies performed with by ICP-MS are compared. The accuracy of the calculated results is proved, and the possibility of their use for predicting the efficiency in forming M⁺⁺ in ICP-MS was demonstrated.

Polarization holographic recording of diffraction gratings and their subsequent erasure have been investigated on As₂S₃–Se multilayer nanostructures. The work investigates how preexposure to actinic laser radiation up to complete photoinduced changes in the optical properties affects the formation of diffraction gratings in the studied structure. It is shown that the preexposure of an As₂S₃–Se multilayer nanostructure (MNS) leads to photobleaching, and the maximum achievable diffraction efficiency (DE) of 35% does not change; however, the required exposure value is increased. It is also shown that exposure using one laser beam results in complete erasure of the diffraction grating recorded up to the maximum. Seven recording–erasure cycles show that the kinetics of the increase in diffraction efficiency and its maximum value do not change, which indicates that the As₂S₃–Se multilayer structure is capable of reversible holographic recording under orthogonal circular polarization. Study of the gratings recorded with an atomic-force microscope shows that the main factor determining the diffraction efficiency value is modulation of the relief, the depth of which is greater than 200 nm.

Silicon dioxide has been produced by deposition from an aqueous solution of Na₂SiО₃ · mH₂O. The particle size of the main faction of the synthesized material determined using an electron microscope ranges from 12 to 16 nm. According to XRD phase analysis, an amorphous modification of silicon dioxide has been obtained. It was then used to synthesize a thin-layer SiO₂/Ni composite via electrolysis to determine the possibility of using it in the negative electrodes of miniature LIBs (LIBs). Studies of the SiO₂/Ni composite in a prototyping lithium-ion battery in the galvanostatic mode have shown stable cycling in the voltage range from 0.40 to 0.15 V indicating promising usage in LIBs.

The surname of the third author should read Hajiyeva.