Synthetic Sorbent Materials Based on Metal Sulphides and Oxides focuses on development of inorganic nanomaterials for removal of metallic species from the aqueous environment. General synthetic methods to prepare such materials are lacking. This book investigates problems of controlled synthesis of these materials and the effect of their morphological characteristics on their sorption capacity. • Synthesizes experimental data on the synthesis of micro- and nanoparticles of zinc, copper, and cadmium sulfides, iron oxides, and manganese oxyhydroxide. • Discusses controlled synthesis of zinc, cadmium, and copper sulfide particles and their sorption properties. • Describes production of iron oxides (hematite and magnetite) and manganese oxyhydroxide particles. • Features numerous SEM images of the obtained nanostructures and original graphs of various characteristics. • Offers practical recommendations. This book is of interest to researchers and scientists working with inorganic synthesis and properties of sorption materials.

The paper describes the tests carried out for the extraction of radionuclides Sr-90, Cs-137 and Co-60 by manganese oxyhydroxide in order to compare the sorption properties of the respective particles with Sr(II), Co(II), Ce (III), Eu (III) ions. It was found that the recovery efficiency and the sorption capacity with respect to metal ions decrease in the MnOOH -> MnO2 -> Mn(3)O(4 )series. The tests proved that the extraction of the radionuclides from tap water by MnOOH particles was 53.7%, 83.5% and 93.1%, respectively. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

The paper describes the methods for the monitoring and improving of operational parameters of the polymeric scintillation detectors and optophotonic components in the surface layer forming process and shows some results of the quality control of ultraprecision optical surface in nanoscale. Important correlations between machining conditions, surface characteristics and longterm performance of polymeric scintillation detectors were found.

The zinc selenide films were synthesized using an electrochemical method in alkaline electrolyte. The influence of deposition options (zinc ions concentration, cathodic current density and electrolysis duration) on ZnSe films formation is discussed. It is shown that the increase of film thickness and its porosity is observed at increase of current density and zinc ions concentration in electrolyte. The most compact films are formed when the zinc concentration in the electrolyte is less than 0.05 M and the current density is not higher than 35 mA/cm2. The obtained ZnSe film had p-type conductivity and a resistivity of 105-106 Ohm·m. It was synthesized heterostructure ZnS/ZnSe/Ni including the p-n transition. The parameters of the diode heterostructure were determined by the dark IV-characteristic.

The magnetic particles of iron oxides are promising materials for the purification of water from ions of heavy metals and radionuclides. Their advantage compared to other sorbents is the ability to extract by applied magnetic field, which greatly simplifies the task of extraction, separation and processing in cleaning technologies. The aim of this work is investigation of temperature and concentration of iron in the solution effect on the phase composition, nanoparticle size and their magnetization. Phase magnetite in the sample increases with increasing temperature and the magnetization decreases slightly with increasing the initial concentration of iron in solution. We found that regardless of the conditions of deposition formed spherical particles whose average size ranges from 7 to 15 nm. The sorptive capacity of the particles is virtually independent of the phase composition and for cobalt is about 18 mg/g. For sorption-based material magnetic particles Fe3O4 recommended to carry out the deposition process at a temperature not lower than 80°C. The concentration of iron in solution must be within 0,15–0,3M. The particles obtained contain in their composition at least 90 wt.% of magnetite phase and are characterized by a magnetization in the range of 65–70 A·m2/kg. Also in the paper is comparing efficiency of extraction and sorption capacity for cobalt particles by different phase of magnetite and hematite.

Chromium oxide ceramics may be considered as a new generation of ceramic materials for cutting tools with considerably improved high speed cutting performance. The present work is focused on the development of Cr2O3 nanocomposite materials fabricated with the Field Activated Sintering Technique (FAST). The main objective of the proposed work is to study the influence of electric field on the densification process during FAST sintering of the materials in the Cr2O3-AlN system with nanosize microstructure. Additional objectives are to characterize mechanical properties of the obtained Cr2O3 ceramics. The work aimed to develop composite materials based on Cr2O3-based nanoparticles for cutting, then to check their cutting properties and to work out the recommendations for their use for processing of various materials, accordingly.

Zinc oxide is a promising material for the fabrication of thin film layers for a new generation of photovoltaic devices and solar thermal collectors, due to the unique optical and electrical properties as well as the propensity to form fil­amentous one-dimensional submicron structures, namely nanowires, nanorods, nanotubes, nanobelts, and hierarchical nanostructures with developed surface and projected superhydrophobicity. We identified the possibility for a develop­ment of planar single-layer antireflection coatings and/or arrays of nanorods of this material as having the shape of hexagonal prisms, and demonstrating the moth eye effect on the substrates of transparent conductive tin dioxide and on silicon wafers with embedded homojunctions. The optimization of the pulsed electrodeposition of zinc oxide arrays adjust the size of parabolic nanonipples for the implementation of antireflection coatings with the moth eye effect on var­ious substrates, including flexible. The antireflection coatings will be developed for thin-film photovoltaic devices of substrate configuration based on kesterite, tin sulphide, and fullerene layers, for the cadmium telluride based photovoltaic cells with bilateral sensitivity of superstrate configuration on the flexible sub­strates and for optoelectronic devices based on zinc selenide for the ultraviolet spectra.

The results of structural and optical investigations of thin carbon films deposited from the mass-separated beam of accelerated C60 ions with energy of 5 keV are presented. The substrate temperature ranged from 100°C to 400°C. It was established that change of the TS from 100°C to 400°C leads to the consecutive formation of diamond-like carbon (DLC) films with amorphous state and superhard nanocomposites consisting nanographite structures (1-2 nm) surrounded by a diamond-like amorphous matrix. For amorphous films the band gap (Eg) was in the range of 1.2 - 1.4 eV. For nanocomposite films on optical absorption spectra, there are two energy components: one with a narrow Eg = 1 eV, which is associated with three-dimensional nanocrystals of graphite, and the other - with a wide optical gap (Eg =3,45-3,55 eV) that corresponds to the diamond-like amorphous matrix of nanocomposite. According to the results of scanning tunneling microscopy (STM) and tunnel spectroscopy (TS), the size of graphite nanocrystals is about 1-2 nm and an amorphous shell around the graphite nanocrystals had a thickness of about 1.5 nm. The graphite component had n-type conductivity and an amorphous component had p-type conductivity. The electrical conductivity of such semiconductor nanocomposite was 103 S/m that to 6 orders higher compared to the DLC film in the amorphous state.

Abstract In the paper, the issue of the cermet cutting tools wear resistance was addressed. The tool inserts made out of cermet composites were exposed to the ion implantation with ions of nitrogen N+ and with combination of nitrogen N+ and aluminum Al+ ions. In order to assess the impact of the ion implantation, the samples of stainless steel EZ6NCT25 were turned with the standard cutting tools and with the inserts after ion implantation. The results in general confirmed better wear resistance of the ion implanted inserts. In particular, they performed 20-40% smaller friction. After some time, when the destruction of the implanted surface layer took place, the friction coefficient rose up to the value typical for non-implanted inserts. For the implanted inserts, the wear index VB appeared to be lower, and even visual assessment revealed distinguishably smaller wear than in case of tools without ion implantation.

Nanostructured ceramic materials and compositions based on them find an increasing application in all branches of science and technology. At the same time, the performance properties of new ceramic nanomaterials (strength, adhesion, optical and others) are significantly different from properties of traditional ceramics, which were used before. The qualitative characteristics of nanoceramics are largely determined by the initial structure and methods of nanopowder synthesis, as well as by the characteristics of conditions and methods for their consolidation. This work is devoted to the synthesis of nanopowders and effective method of its sintering for the production of nanoceramic materials which have special mechanical properties, e.g. components with increased modulus of elasticity ("ceramic steel"), etc. It makes it possible to effectively use them in aerospace industry.

The paper presents the preliminary results of investigations on hot pressure sintering under the alternating current. The aluminium oxide Al2O3 and tungsten monocarbide WC powders of submicron grain sizes were used to obtain the sintered structure at various temperatures, pressures, current and other physical conditions. The analysis of the physical properties of obtained ceramics revealed increased hardness and even some elasticity and substantially increased flexural strength. Out of the nanostructured mixture of Al2O3 and WC powders in proportion 50–50%, the inserts for cutting tools were made. The comparative analysis of those inserts with the ones typically available in the market confirmed increased durability (up to 30%), as it had been expected. The obtained structure could be further improved, and if the grains in the sintered material become smaller than 1μm, even better physical properties, wear-resistance and durability could be expected.

The paper presents the results of investigations on hot pressure sintering under the alternating current. The powders of different grain sizes were used for the sintering to investigate the impact of the powder on the final sintered structure and relative density. The additional experiments were focused on the kinetics of the Al 2 O 3 nanopowders sintering. They confirmed that the time of the process duration is dependent on the temperature and the applied pressure. However, compared to the powders of tungsten monocarbide, it depends on the temperature rise speed in rather small degree. Discussion of the results pointed out that the obtained data, both theoretical and experimental one, confirmed possibility that during the sintering process the dislocations might appear and spread. It seemed reasonable to assume that in the low voltage regime the activated sliding with diffusion accommodation prevails, while in the high voltage regime the dislocation creep does.

In the paper, some problems of nanoceramics production are discussed.Some crucial stages in the production cycle are pointed out, among others the nanoscale powder synthesis and the compaction during the sintering.A novel method of hot pressing under the directly applied electric current was proposed.Some examples of advantageous characteristics obtained through the new method were provided.The hot press sintering under the electric current is suitable for the production of structured nanoceramics, cutting tools for industrial applications, filters for industry and the functional nanoceramics like optical elements or biomedical implants.

This work describes the investigations on the sintered nanostructured materials, especially tungsten carbide (WC). The novel method of hot pressing of nanopowder in vacuum with the applied electrical provided the material of advantageous characteristics compared to the typical hot pressing. The sintered material revealed grain size mainly below 1 mu m, almost no porosity, and high strength.

This work describes the investigations on the shrink-fitted joints. The models of the marine engine cranks and pivots were made in the scale 1: 5 considering the real manufacturing conditions of the large-sized crankshafts. The results of the ultrasonic measurements of the stresses were compared to the temperature distribution during the cooling of the assembled couplings. The conclusion was that the unsteady stress distribution might be caused by the unsteady cooling process. As a consequence, more tight joints may reveal not better ability to bear a load torque.

One of the most effective and simple methods of natural and wastewaters from heavy metals and radionuclides is a sorption extraction. Assorbents proposed the use of polymers, natural materials, and other oxides. Theparticles of iron oxide Fe2O3 and Fe3O4 are among the most promising materialsfor inorganic heavy metal ions and radionuclides from water bodies. Theiradvantage over other compounds is the lack of toxic effects on the human body,low cost, and ease of obtaining precursors.

An actual problem is the synthesis of ceramic composite materials based on refractory compounds to produce nanostructured materials with high mechanical strength, namely, flexural strength, fracture toughness, hardness, heat resistance and thermal strength. Of particular interest is the transformational-reinforced ceramic, which is not inferior in strength characteristics of conventional structural alloys. Particularly noteworthy are composites based on the composition ZrO2 / Al2O3, which have high strength and toughness in comparison with monozirconium or monocorundum ceramics.