Pure (ligandless) nanoparticles of titanium (4–20 nm) in a porous NaCl matrix (29–43 nm) were synthesized by the method of electron beam physical vapor deposition (EB-PVD). Independent electron beams were used to preheat the compacted cylinder from NaCl salt and Ti ingot up to formation of liquid melts. Evaporation of the initial materials from the melt surface, vapor flow mixing, and deposition of the mixed vapor on the surface of the water-cooled copper substrate took place in vacuum. Deposited condensate composition was regulated by the intensity of the vapor flows of evaporated materials. Results of studying the structure (SEM) and element composition of the condensate (EDS), phase composition (XPA), and the size of the nanoparticles (TEM) and crystallites (XPA + Scherrer equation), as well as their thermal stability in NaCl–Ti–O system (TGA), are given. It is shown that the dimensions and phase composition of titanium nanoparticles can be further controlled by heat treatment of the initial NaCl–Ti condensate, produced at low condensation temperatures. Investigations of the kinetics of oxidation of NaCl–Ti condensates in air (TGA) show that breaking of the vacuum in the chamber titanium nanoparticles in the porous NaCl matrix demonstrates high adsorption ability to moisture and oxygen from the air. With temperature increase up to 250–400 °C, practically all the moisture is removed, and further heating activates the process of titanium nanoparticle oxidation. Obtained results are considered from the viewpoint of physical and chemical adsorption.

Electrometallurgy Today, 2020, №02. SOVREMENNAYA ELEKTROMETALLURGIYA Quarterly scientific-technical and production journal. ISSN: 2415-8445, Since 1985. Text in Russian, contents and summaries in English. The journal presents the results of theoretical and experimental research carried out at the PWI in the field of electrometallurgy. Special attention is given to electroslag technology (electroslag melting, refining and casting). The journal is divided into the following main sections: electroslag technology; electron beam processes; plasma arc technology; vacuum arc remelting and vacuum induction melting; general problems of special electrometallurgy.

Background: Nanomaterials for medical applications, preparations with silver and copper nanoparticles attract special attention. Silver has stronger antimicrobial properties than does penicillin, biomycin and a number of other antibiotics. Nanoparticles of copper and copper oxide also exert a pronounced antibacterial effect. Objective: Further development and creation of medicines based on silver and copper nanoparticles require selecting a method for synthesis of nanoparticles that would ensure production of various nanomaterial compositions. Method: The method of electron beam evaporation and deposition of materials in vacuum opens up wide possibilities. The idea of using this approach is the possibility of simultaneous evaporation and deposition of mixed molecular flows of two substances onto a substrate. Results: The paper presents the results of investigation of the structure of porous condensates of Ag-NaCl and Cu-NaCl composition; chemical and phase compositions and dimensions of nanoparticles, produced from the vapour phase by EBPVD method. Silver and copper nanoparticles in a porous matrix have considerable sorption capacity relative to oxygen and moisture. Along to concentration change, phase composition of nanoparticles can be also controlled by heat treatment of the initial condensate produced at low condensation temperatures. Silver and copper nanoparticles can be converted into stable colloidal systems. Conclusion: Physical synthesis of silver and copper nanoparticles by EBPVD method allowed producing nanostructured material in the form of a dry substance for preparation of the required colloidal solutions. TGA method provides an indication of the processes of transformation in Ag-O system. Ag2O decomposes at the temperature of 460°C. Controlling the activity (size) of nanoparticles allows creating various compositions of nanomaterials, based on copper.

The physical synthesis of iron oxide nanoparticles obtained from the vapor phase using the electron beam physical vapor deposition method is considered. The results of studying the structure of porous condensates of iron—sodium chloride compound, chemical and phase compositions, as well as nanoparticles size are presented. With a rapid removal from vacuum, iron nanoparticles are oxidized in the air to magnetite. In the initial state, they have significant sorption capacity with respect to oxygen and moisture, therefore, with further heating in the air, the porous condensate mass decreases up to the temperature 650 °C, primarily due to the desorption of physically sorbed moisture. Physically adsorbed oxygen participates in oxidation of Fe 3 O 4 –Fe 2 O 3 in the range of 380–650 °C. An increase in condensation temperature is accompanied by an increase of nanoparticle size, as a result of which the total surface area of nanoparticles is significantly reduced, and, consequently, their sorption capacity is decreased. Even without stabilization, such nanoparticles studied as ex tempore prepared aqueous dispersion have characteristic anti-anemic effect in the laboratory animals that can be used in medicine.

The paper gives the results of studying the structure of porous condensates of Fe + NaCl composition, chemical and phase compositions and dimensions of nanoparticles produced from the vapor phase by EB-PVD. Iron nanoparticles at fast removal from the vacuum oxidize in air and possess significant sorption capacity relative to oxygen and moisture. At heating in air, reduction of porous condensate weight occurs right to the temperature of 650 °C, primarily, due to desorption of physically sorbed moisture. Final oxidation of Fe3O4 to Fe2O3 proceeds in the range of 380 °C–650 °C, due to the remaining fraction of physically adsorbed oxygen. At iron concentrations of up to 10–15 at%, condensate sorption capacity is markedly increased with increase of iron concentration, i.e. of the quantity of fine particles. Increase of condensation temperature is accompanied by increase of nanoparticle size, resulting in a considerable reduction of the total area of nanoparticle surface, and, hence of their sorption capacity. In addition to condensation temperature, the size and phase composition of nanoparticles can also be controlled by heat treatment of initial condensate, produced at low condensation temperatures. Magnetite nanoparticles can be transferred into stable colloid systems.

На основе пористых конденсатов композиции NaCl-Ag, синтезированных электронно-лучевым испарением и конденсацией в вакууме, получены стабильные водные коллоидные системы с наночастицами серебра.Стабилизация наночастиц в водных коллоидах производилась с помощью сывороточного альбумина человека.При внесении серебра в виде измельченного конденсата NaCl-Ag в количестве 100 мг/л в водный (0,1...1,0 %) раствор альбумина, в полученной гетерогенной системе доля наночастиц серебра, переходящих в коллоид, определяется концентрацией альбумина в растворе и кислотностью раствора (pH).Стабильное значение среднего размера частиц (6...10 нм) во времени и максимальная их доля достигаются в водном коллоидном растворе, содержащем 110 мг/л альбумина при его кислотности в диапазоне значений pH = 7,1…7,7.При повышении pH среды доля наночастиц серебра в коллоиде понижалась до 2 мг/л и оставалась неизменной вплоть до pH = 10.библиогр.23, ил. 7. EB PVD; конденсаты; наночастицы; серебро; альбумин; коллоид; кислотность К л ю ч е в ы е с л о в а :

Рассмотрены наноструктурные конденсаты NaCl-Fe, полученные электронно-лучевым испарением (методом EB PVD) из двух источников и физическим осаждением смешанного парового потока на водоохлаждаемую медную подложку.Микроструктуру конденсатов NaCl-Fe изучали сканирующей электронной микроскопией на приборе VEGA 3, а наноструктуру -просвечивающей электронной микроскопией на приборе H-800.Отделенные от подложки конденсаты исследовали на воздухе методом термогравиметрического анализа (ТГА) в диапазоне 20…650 о C на анализаторе TGA 7. Представлены результаты исследований микроструктуры и сорбционных свойств конденсатов NaCl и NaCl-Fe (28 мас.% Fe) при насыщении их влагой.Проанализированы данные ТГА с обработкой по моделям Коутса-Редферна и Фримена-Кэрролла и расчетом энергии активации и порядка реакции разложения при нагреве.Показано, что при извлечении конденсатов из вакуумной камеры наночастицы железа в пористой матрице NaCl активно адсорбируют из воздуха не только влагу, но и кислород.При нагреве в дальнейших исследованиях десорбция влаги и кислорода приводила к монотонно ниспадающим ТГА-зависимостям.Библиогр.17, табл. 1, ил. 5. К л ю ч е в ы е с

The paper examines the structure of porous Ag + NaCl condensates and analyzes the phase and chemical composition and sizes of Ag nanoparticles produced by electron-beam evaporation and vacuum condensation. It is shown that Ag nanoparticles are highly adsorptive to air oxygen in a porous salt matrix. Thermogravimetric analysis is used to study the kinetics of variation in the weight of porous NaCl and Ag + NaCl condensates during heating (to 650°C) and cooling in air. The results are considered in terms of physical and chemical adsorption. Stabilized colloidal systems of silver nanoparticles are obtained. Photon correlation spectroscopy is employed to determine the size of nanoparticles in aqueous solutions with surfactant agents.

Currently, a number of general methods for nanoparticles synthesis have been created. In terms of opportunities for industrial production of nanomaterials in Ukraine today, the most advanced is nanotechnology based on physical methods of their obtaining. Therefore today finding stable organic colloidal dispersions stabilized by surfactants and standardization of the experiments techniques in vitro and in vivo, development of safety criteria, and acceptable thresholds for toxicity of metal nanoparticles is an urgent problem. Physicochemical properties of nanoparticles of silver and copper oxides in colloidal solutions of albumin, polyvinylpyrrolidone, and dextran have been studied. Cytotoxicity of nanoparticles of silver and copper oxides in polyvinylpyrrolidone and dextran was evaluated. Toxicity of silver oxide nanoparticles was assessed during per os subacute experiment on Wistar rats. High toxicity of 46.6 mg/l concentration of silver oxide nanoparticles was detected. Biochemical study of enzyme system activity, measurement of trace elements content in whole blood and morphological study of blood cellular composition enabled to reveal minor changes in the composition of blood cells and amount of trace elements, as well as a significant reduction in ceruloplasmin activity and increased activity of ATP and zincprotoporphirine in response to per os subacute exposure of silver oxide nanoparticles with a size of 32 nm and 2.5 mg/l concentration.

Experimental investigations were made of the thermodynamic and transport properties of amorphous superconducting La/sub 100-x/Al/sub x/ alloys (x = 18, 20, and 25). A negative temperature coefficient of the electrical resistivity was observed. It was attributed to the temperature dependence of the Debye-Waller factor at high temperatures and to interference of the electron-electron interaction with the elastic impurity scattering of electrons at low temperatures. The temperature dependences of the specific heat and of the magnetic susceptibility indicated the possibility of appearance of additional localized magnetic moments as a result of amorphization of the alloys.

Internal friction measurements were used for the examination of Cd + Zn alloy single crystals. It was established that the interaction energy between solute Zn atoms and dislocations in basal planes is 0·12 eV.