This paper is devoted to the investigation of basic technological parameters of electrospinning process which influences on the fiber diameter. Chitosan solution in 70% acetic acid with modifying agent (~ 1 wt% ) was used as spinning solution. It was experimentally established the dependences of fiber diameter from volume flow rate of spinning solution and from the voltage which is given on the spinning solution. It is determined of defect number of fiber structure from volume flow rate of spinning solution. It was found out that average diameter of defects in the form of drops is sufficiently increased when the volume flow rate is also increased.

Цель данной работы – изучение влияния технологических параметров процесса электроформования из раствора хитозана на конечный диаметр волокна (D) и структуру нетканого материала.

The oxide microstructures formation and growth were studied on the surface of filaments heated electrically. The molybdenum samples were 0.1 m long and 200 mcm in diameter, the tungsten samples were 0.1 m long and 300 mcm in diameter. The successive stages of oxide microstructures growth were observed. The temperatures of microstructures origin were determined, the linear growth rates were found, the oxides structures finite sizes were measured.

Целью работы было изучение особенностей роста оксидных слоев на поверхности вольфрамовых и молибденовых проводников.

Объектом исследований служили тонкие проволочки из молибдена марки МЧ ( ) и вольфрама марки ВА-1 ( ), длиной , нагреваемые электрическим током в воздухе. Образование и рост оксидного слоя на поверхности проводника непрерывно регистрировался с помощью цифровой камеры и оптического микроскопа (х110). Установлено, что в процесс формирования оксидов на поверхности данных металлов носит сложный стадийный характер, и зависит в первую очередь от температуры образца, которая определяется силой тока.

1 Physical-chemical Institute at the Vasyl Stefanyk PreCarpathian National University, Ivano-Frankivsk, Ukraine
2 B.I.Stepanov Institute of Physics of the National Academy of Sciences of Belarus, Minsk, Belarus

In this paper study PbTe thin films on silicon, germanium, micaceous and glassy substrates as well as on silica substrates covered with SiO2-, GeO2-and HfO2-gel-films that prepared by means of precipitation from the gas – dynamical steam. The films surface microstructure and optical properties in middle IR-range subjected to their preparation conditions and nature of substrates were investigated by means of scanning electron microscopy and FTIR spectroscopy. The analysis of physical properties of the substrates used permitted us to suppose the correlation between the substrates thermal conductivity value and the described characteristics of the PbTe films at the same preparation conditions.

Molecular dynamics simulation of non-closed nanostructure behavior is carried out. These structures are formed by self-rolling of nano-sized bilayer Al-Cu, Сu–Ni metallic films. Without external actions edges of nano-sized films make weakly damped harmonic oscillations during formation process. Dependences of amplitude and oscillation frequency of nanostructures on initial film sizes are investigated. Geometric parameters of initial films, at which non-closed nanostructures oscillate without edges clinging, are determined. Peculiarities of film composition and crystallographic orientation influence on non-closed nanostructure oscillation are revealed. It is shown that layer composition changing and defect saturation of initial film can purposefully have effect on amplitude and frequency of oscillation.

Initiation and evolution of plastic deformation in hexagonal close-packed phase of a titanium crystallite with grain boundary under uniaxial tension is carried out on the base of molecular dynamics simulation. Influence of loading rate on structure-phase changing is studied. A correlation between dependences of atom number with slip vector more than 0.04 lattice parameter and potential energy changing on deformation is revealed. It is shown that increasing of loading rate leads to a growth of threshold deformation value under which local atomic displacements are generated in simulated crystallite. Atomic system behavior in regions of local atomic displacement initiation and evolution is investigated.

1Институт сверхтвердых материалов им. В.Н. Бакуля НАН Украины, г. Киев, Украина
2 Институт электросварки им. Е.О. Патона НАН Украины, г. Киев, Украина

A new green technology of electro conductive materials plasma dispersion with highly productive one-step cycle production of nano dispersions in various liquids is described. The physical and chemical characteristics of produced colloidal solutions are presented, specifically for nano Silver dispersion in food Glycerin. The physical and chemical characteristics of produced colloidal solutions are presented, specifically for nano Silver dispersion in food Glycerin. The advantages of new technology and unit are described.

In this paper we use the Mn-substituted calcium fluorapatites obtained by synthesis in saline melt KCl-NaCl at temperature of 700° C in an inert atmosphere of helium and in air. Samples of CaMnFAP were investigated by X-ray diffraction analysis (XRD), IR vibration spectroscopy and UV-visible electron spectroscopy, fluorescent spectroscopy, scanning electron microscopy. We assume that synthesis Mn-substituted apatites in the saline melt in the air and inert atmosphere is accompanied by the anionic and cation substitution (Ca2+ → Mn2+ and PO43-→ MnO32- respectively). In the case of synthesis in an inert atmosphere substitution of Mn2+ for Ca2+ prevailed, the air promotes the anionic substitution.

Целью данной работы является синтез апатитов с одновременным замещением ионов РО43- на ионы MnO32- и ионов Са2+ на Mn2+, а также исследование их структуры.

In this paper methods of obtaining lead fluorapatite (PbFAP) by a solid state synthesis and synthesis in saline melt NaCl-KCl are studied. Comparison of products obtained by these methods is carried out. By means of the X-ray diffraction phase analysis, spectroscopy of diffuse reflectance and IR spectroscopy, it is shown that reactions in all cases proceede through various routes, and therefore lead fluorapatites having quite different properties are obtained. At solid synthesis of Pb PbFAP a loss of weight exceeding theoretical amount is reveald that suggests a course of collateral reactions. Data on IR spectroscopy, besides the РО4 groups, show the presence of СО3 groups and sorbed H2O in PbFap structure.

Light emitting devices (LEDs) were fabricated using as an emitting layer the blends of poly(n-vinylcarbazole)(PVK) and core-shell quantum dots CdSe/ZnS(QD) in different mass ratios. Thin films were obtained by spin-coating on quartz wafers to investigate absorption and fluorescence properties or on glass substrates coated with ITO to studies electroluminescence. It was found that the relative emission intensity of the CdSe/ZnS to PVK in the blends depended on the mass ratios, and the emission from the QDs was the strongest as the mass ratio of CdSe/ZnS to PVK was 2:1.

Single-phase nanometric powders of manganite La0.52Sr0.28Mn1.2O3 with the average grain size 30, 60 and 200 nm were synthesised by method of co-precipitation of salts. It is shown that the grain size significantly influences on electric and magnetic properties of the samples under investigation. Electroresistance becomes a few orders more and the Curie temperature significantly decreases, and also the magnetic susceptibility peaks become broader when grain size decreases. It is revealed that the compact samples of initial powders show a normal (usual) magnetic hysteresis while the ceramic samples that were obtained by sintering «compacts» at 1270 K, show an "abnormal" magnetic hysteresis.

Целью настоящей работы было получение однофазных материалов с различными размерами кристаллитов и изучение влияния размера частиц на электрические и магнитные свойства.
Нанокристаллические образцы манганита состава La0.52Sr0.28Mn1.2O3 со средним размером кристаллитов 30 nm были получены методом совместного осаждения растворов нитратов лантана (марки Ч) и марганца (марки ЧДА) в растворе аммиака.

1Институт физико-органической химии и углехимии им. Л.М. Литвиненко НАН Украины
2Донецкий физико-технический институт им. А.А. Галкина НАН Украины

1The L.M. Litvinenko Institute of Physical-Organic Chemistry and Coal Chemistry NAS of Ukraine,
2The A.A. Galkin Donetsk Institute for Physics and Engineering NAS of Ukraine

Metal-carbon globular nanostructures obtained from graphite and graphite intercalated compounds. The size of the smallest particles is 6.5 – 7.0 nm. The smallest-sized particles tend to aggregate with the formation of different-sized sub-micron aggregates (12 – 370 nm) with composition: 89.5 % copper and 4.4 % carbon; density 7.54 g/cm3. The mechanism of formation due to the interaction of copper clusters with a graphite crystallites. This leads to a detached graphenes and coiling them in metal-carbon globular structures. It was analyzed the temperature dependence of the conductivity of copper-graphite compounds (metallic-type conductors).

1 Research Institute ELIRI, Republic of Moldova
2Institute of Electronic Engineering and Industrial Technologies, Academy of Sciences of Moldova, Republic of Moldova
3State University of Moldova, Republic of Moldova
4Institute of Applied Physics, Academy of Sciences of Moldova, Republic of Moldova

A technique for formation of CdS nanocrystals in a Sevilen polymeric matrix by the “cluspol” method is proposed. The optimum conditions of synthesis of CdS nanocrystals are found. The crystallite sizes are estimated using the X-ray diffraction analysis. The results of studying the luminescent properties of the resultant “polymer + nanodimensional CdS” structures are described.

1Институт биоколлоидной химии им. Ф.Д. Овчаренко НАН Украины
2Институт теоретической физики им. Н.Н. Боголюбова НАН Украины

This research was devoted to investigation of the peculiarities of a weak pulsed electric field influence on metal ions bioaccumulation and colloid silver/copper formation in bacteria and yeast cells. The increase of bioaccumulation value as a result of superposition of two mechanisms: a biosorption and field induced sorption, was estimated. Amplification of bactericide properties of hybrid materials based on microorganisms and silver (copper) nanoparticles as a result of synergetic effect of copper additives, which catalyzed mixed silver and copper particles formation, was observed.

Цель данного исследования состояла в изучении влияния параметров внешнего импульсного электрического поля (ИЭП) на взаимодействие ионов серебра и меди с культурами P. fluorescens ВКПМ В5040 и C.albicans УКМ690 и на условия формирования наночастиц металлов в биоматрицах.

Resonant tunneling conception has been used to explain the thermo-electrical phenomenon in molecular nanosystems. Thermovoltage as a function of the temperature is calculated. The reverse of the thermovoltage sign under resonance tunneling through HUMO and LUMO levels is demonstrated. The dependence of the thermovoltage on the distance between electrodes is calculated. A result of calculations is in good agreement with experiment data.

Інститут металофізики ім. Г.В. Курдюмова НАН України, м. Київ, Україна
*Институт физики металлов УрО РАН, Екатеринбург, Российская Федерация

Diffusion characteristics of carbon atoms in metastable alloy Fe – 32 wt.%Ni with nanofragmented structure were investigated by X-ray method. Nanofragmented structure was obtained using cyclic martensitic g-a-g-transitions. The conclusion about significant carbon diffusion acceleration on dislocations and nanofragments subboundaries at low temperatures is made. Diffusion coefficients at 100˚C, that were calculated using X-ray method, are two times smaller than coefficients, calculated using radioisotope method. Such difference can be explained by the fact that X-ray method is more sensitive for volume diffusion of carbon in lattice, and radioisotope method is sensitive both for volume diffusion of carbon and for diffusion on dislocations and subboundaries of nanofragments.

В цій роботі проведено дослідження дифузії атомів вуглецю у Fe – 32 мас.%Ni сплаві, в якому за допомогою циклічних g-a-g-мартенситних перетворень створено фрагментовану структуру наномасштабного рівня з високою густиною дислокацій у фрагментах.