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In this work, the surface energy of titanium crystal faces was estimated using the electron-statistical method, taking into account the contributions of the dispersion, polarization, and oscillation corrections. Using an analytical relationship, the values of the work function of close-packed faces of polymorphic modifications of titanium are calculated from the values of the surface energy of single crystals taking into account the crystal structure. The influence of polymorphic transformation and temperature on the anisotropy of the studied properties is shown. Based on the values of the surface and interfacial energies, which consist of the average configurational energy and the energy of chemical interaction of two parts of the metal, the cohesive energy of - and -titanium is estimated and its dependence on temperature is shown. On the example of tungsten-titanium and molybdenum-titanium systems, the fundamental possibility of calculating the change in the work function depending on the concentration of the surface-active component in bimetallic systems is shown, which makes it possible to predict the service life of the material.

Objective. The purpose of the study is to experimentally measure the surface energy of solids during their grinding.Method. The study is based on the use of methods for determining the surface tension of solids. At least 20-25% of all electricity produced in the world is spent on grinding materials in industry. When the resulting particles are reduced to tens of nanometers, the contribution of surface energy (st) to the grinding work becomes so large that it is difficult not to take it into account. Measuring the surface tension of liquids has long been proven. But measuring (st) of solids causes great difficulties. Currently, more than twenty methods for determining (st) are known.Result. Based on the phenomenon of spontaneous bending of thin thread-like structures, a method for determining (st) has been developed. Examples are given in which (st) at the phase interface plays an important role in obtaining samples with a microstructure using the method of severe plastic deformation (SPD). To obtain fine metal powders, one of the variants of the SPD method has been proposed. A method has been found for the physical activation of aluminum granules, which increases the reaction rate of the metal in an aqueous environment by about a thousand times. This is necessary for the development of an anaerobic power plant capable of operating at great depths.Conclusion. The new technology makes it possible to obtain high-purity, non-oxidized metal powders without toxic waste and emissions and with energy costs lower than in all known methods.

The aim of the work is to build a model of the surface layer of objects (crystals) and to elucidate the role of surface energy in physical processes occurring in the nanoscale region. Frame hydrocarbons of the adamantane type, which have a highly symmetrical diamond-like structure, were chosen as objects. On the basis of an empirical model, the thickness of the surface layer and the surface energy of framework hydrocarbons were determined for the first time. In practice, this is very important, since all physical and chemical processes significant in operation occur through the surface layer. For adamantane, the thickness of this layer is 21.6 nm, and for diamond it is 8.2 nm, that is, they represent a nanostructure. Such a difference in the thickness of the surface layer of the two types of structures causes their sharp difference in their properties, in particular, in their surface energy, which determines their mechanical properties. For adamantane, the surface energy is 378.7 mJ/m2, and for diamond it is 9400 mJ/m2. In practice, researchers have found that under shock-wave action, the degree of adamantane→diamond transformation is almost 30%. The work of adhesion for frame hydrocarbons is 400–500 mJ/m2, and internal stresses are 35–45 MPa, which in the surface layer lead to a decrease in adhesive strength and the inverse Hall-Petch effect.

Most food mixtures, where the liquid acts as a dispersion medium, are formed with the participation of water and aqueous solutions,. The formation of stable surface interactions in disperse systems with the participation of water is based on overcoming the forces of surface tension at the interface between the phases. The aim of the research is to analyze the effect of mechanical activation during stirring and microwave exposure on the surface properties of water and aqueous solutions. The object of the research is distilled water, bottled “Berdovskaya taiga” drinking water, an aqueous solution of NaCl (3.33%), an aqueous solution of NaCl (3.33%) with the addition of 1% flour with stirring. The main research method is the method of capillary rise of liquid in a tube of small cross section, partially immersed in liquid. It has been established that both mechanical and electromagnetic effects change the surface energy of water and aqueous solutions. But their influence is ambiguous. Surface tension during mechanical activation by stirring decreases to a certain minimum for different time intervals for different solutions, and then increases to a certain level. The retention time of the reduced surface energy of distilled water after stirring at a frequency of 100 rpm is 60–80 s. There is a tendency for a noticeable effect of impurities on the surface tension. The more complex the solution and the higher the concentration of impurities, the lower its surface energy. According to the results of the research, for technological purposes, for example, dough kneading, it is recommended to mechanically process (mix) solutions for dough kneading for 60–70 s or microwave treatment for no more than 20 s.

A new thermodynamic approach for phase stability of a nanoscale material under irradiation taking into account Gibbs free energy of phase formation and nucleation is proposed. The influence of powder dispersion and vacancy saturation on the radiation stability and phase changes of spherical Ferrum nanoparticles during irradiation is determined. The paper shows the possibility of a radiation-induced α-Fe → y-Fe polymorphic transition, and also defines the radiation stability zones of Ferrum nanoparticles. It is shown that the competition between the energy of the accumulated vacancies in the particle, the bulk energy of the phase transformation, and the surface energy of the particle is responsible for the specific behavior of irradiated nanocrystalline Ferrum. [ABSTRACT FROM AUTHOR]

On the basis of the electronic-statistical method, a relationship is obtained and the surface energy and the work function of the electron of the faces of lithium crystals are estimated, taking into account the dispersion, polarization, and oscillatory interactions of the atoms of the surface layer. It was assumed that the crystal lattice has no defects. The expressions for the corrections and an analytical relationship between the work function of the electron and the surface energy are modified taking into account the type of the crystal lattice and the orientation of the faces. The work function of the electron and the surface energy of smooth faces are calculated at the limiting temperatures of the existence of polymorphic lithium phases. The influence of polymorphic transformations and temperature on the anisotropy is established. The temperature coefficient of the work function of an electron in a defect-free crystal is positive and amounts to about 0,1-1 meV. The calculation results are in good agreement with the experimental data for polycrystals.

Based on the parameters of the pair interatomic interaction potential of the Mie-Lennard-Jones for Pt, and using the RP-model of the nanocrystal, the temperature, pressure and size dependencies of the following properties are studied: elastic modulus, thermal expansion coefficient, isobaric heat capacity, and surface energy. The calculation of the equation of state showed good agreement with experiment. The equation of state was calculated along five isotherms: T=300, 1300, 1500, 1700, 1900 K. For the first time, calculations of the temperature dependences of the above properties of Pt in the range from 0 to 1500 K along 0 and 50 GPa isobars were performed from a unified standpoint. Calculations of these dependencies were carried out for both macro- and cubic nanocrystals of 306 atoms. It is shown that with an isobaric-isothermal decrease in the nanocrystal size, the values of the elastic modulus and surface energy decrease, while the values of the thermal expansion coefficient and isobaric heat capacity increase over the investigated temperature range.

The paper deals with the anisotropy of the surface layer and the anisotropy of the free surface energy of cubic ruthenium crystals. This consideration is based on an empirical model of atomically smooth crystals, the thickness of the surface layer of which depends on single fundamental parameter – the atomic volume of an element. Calculations of ruthenium crystals showed that the thickness of the surface layer of ruthenium crystals in all directions does not exceed d(I)3 J/m^2 in the (100) direction. We have considered the problem of gas diffusion in a nanometer ruthenium plate. In contrast to the classical problem, a logarithmic term appears in the resulting equation. This leads to divergence at the origin. Therefore, the boundary conditions must be specified not at x=0, but at x=d(0) – the de Broglie wavelength of electrons. Only in this case the classical diffusion equations are meaningful. It is also important that, according to the obtained equation, the diffusion of the nanoplate depends both on the material of the plate through the diffusion coefficient of the bulk sample and on the size factor. In the classical case, there is no such dependence. Various models have been proposed to describe phase transitions in nanostructures, among which we can mention the Landau mean field method, in which the order parameter is used. We will use Landau's theory, replacing the temperature T with the coordinate h.

This paper proposes a method for synthesis of hexagonal GaN on Si(100) and Si(113) substrates, where nanostructures with an element size less than 100 nm are formed on the surface. It has been established that the method of gas-phase epitaxy from metalorganic compounds in a hydrogen atmosphere on such substrates makes it possible to form semipolar layers of GaN(10-11) and GaN(11-22) with a minimum half-width of the X-ray diffraction swing curve of about 30 arcmin. It is shown that during the formation of a semipolar AlN layer at the initial stage of epitaxy, a corrugated surface is formed on NP-Si(100) from the semipolar planes AlN(10-11) and AlN(10-1-1) with counter-directional c axes. Then, during the growth of the GaN layer, a transition is made from the symmetrical state of the semipolar GaN(10-11) and GaN(10-1-1) planes to an asymmetric state with the orientation of the c axis of the GaN(10-11) layer. That transition is apparently determined by the difference in the values of the surface energy of GaN during epitaxy on the corrugated surface.

Based on the parameters of the Mie–Lennard-Jones pair-wised potential of the interatomic interaction for Mo and W, the potential parameters for an equiatomic Mo - W substitution alloy were calculated. Size dependences for the equation of state, modulus of elasticity, coefficient of thermal expansion, isobaric heat capacity, surface energy and surface energy temperature derivative were obtained. Temperature dependencies of coefficient of thermal expansion and isobaric heat capacity for macro- and nano-crystals of Mo - W alloy were also obtained.

On the basis of the electronic statistical method, expressions for the dispersion and polarization corrections to the surface energy of the crystal faces IA of metals at the boundary with vacuum are obtained and their value are calculated. Both corrections are highly anisotropic. The dispersion correction increases the surface energies of the faces (from 3 to 23 %), the polarization correction reduces them by less than 1 %. Taking into account these interactions improves the agreement between the calculated surface energy and the experimental data of the melts.

In the present work, the surface layer of a coal substance is considered, the structure and characteristics of which are different from the bulk structure. This layer has two levels: d(I) equal to 151,5 nm and d(II) ≈ 10 · d equal to 1515 nm for anthracite. For pure metals d(I) is equal 1 — 6 nm, that is 2 orders of magnitude lesser than the surface layer of the coal substance. The thickness of this layer is of the order of 135 nm for the higher C96 fullerenes. All these features of a coal substance, which has a carbon base and is a polymer with a supramolecular structure, lead to the fact that it is the surface layer that determines the physical processes in it associated with the flow of gases and liquids, as well as with the phenomena of the explosion hazard.

A brief review of the physics of the surface layer of atomically smooth crystals is given. It already contains a fairly large number of practical applications in various fields of interdisciplinary areas. It has been shown that the thickness of the surface layer is determined by one fundamental parameter – the atomic volume of the crystal.

The technological parameters of deposition of high-entropy ionplasma coatings based on Kh18N10T alloyed steel by zirconium, copper and aluminum are studied. It has been established that with increasing evaporator arc current, the surface energy of the coating decreases, which is explained by a rapid increase in its thickness, leading to an increase in the dislocation density in the coating being formed. The optimal value of the arc current is 90–110 A. Coatings obtained at a nitrogen pressure of P=10–3 mm Hg. and the substrate temperature of 400 °C, have the most evenly distributed fine dense structure, the minimum content of the droplet phase, pores, influx, detachments, the highest values of surface energy and an increase in microhardness by 30 %.

Object. Until recently, due to the absence of many solid metal experimental values of the surface energy sSV and the temperature coeffi cient Ds D SV / T not possible to bring the computed values of interfacial energy sSL of the same temperature at which measurements were made of the contact angle, which naturally negatively infl uence in the results of calculations of interfacial energies. At the present time by their calculation them will be able to account the temperature factor for many solid-liquid metal systems. Purpose. The purpose of this paper is calculating interfacial energy between melting metal and another solid metal. The interfacial energy of iron, copper on the boundary with meltings stannum, plumbum is calculated. It is showed that if the wetting angles more than ninety degrees, it then the interfacial energy is more than surface energy of a solid body. In case, when boundary angle is smaller ninety degrees then the interfacial energy less than the surface energy of solid body. Method and Methodology. According to the literature, data know experimental values of contact angles formed by liquid tin, lead on the surfaces of solid iron, and copper their interfacial energy calculated. For calculations, we used the Young’s equation relating interfacial energy with the surface energies of the solid, the liquid and the cosine of the contact angle. Results. It is showed that if the take in to account the temperature at which it the makes a signifi cant is measured, contributes to the of a signifi cant contribution in the interfacial energy. Conclusions. In conclusion, it should be noted that our method of calculation can be also adapted to the investigations of other solid-melt system.

The article uses the thermodynamics of interfacial phenomena to justify the fact that Young’s equations can correctly describe the three-phase equilibrium with any type of interatomic bonds. Wetting, adhesion, dissolution, surface adsorption, and other surface phenomena are important characteristics, which largely determine the quality and durability of materials, and the development of a number of production techniques, including welding, soldering, baking of metallic and non-metallic powders, etc. Therefore, it is important to study them. Using experimental data regarding surface energies of liquids (melts) and contact angles available in the literature, we calculated the surface energies of many solid metals, oxides, carbides, and other inorganic and organic materials without taking into account the amount of the interfacial energy at the solid-liquid (melt) interface. Some researchers assumed that in case of an acute contact angle the interfacial energy is low. Therefore, they neglected it and assumed it to be zero. Others knew that this value could not be measured, that is why they measured and calculated the difference between the surface energy of a solid and the interfacial energy of a solid and a liquid (melt), which is equal to the product of the surface energy of this liquid by the cosine of the contact angle. It is obvious that these methods of determining the surface energy based on such oversimplified assumptions result in poor accuracy. Through the use of examples this paper shows how the surface energies of solids were previously calculated and how the shortcomings of previous calculations can be corrected

The thickness of the surface layer of an atomically pure metal, which turned out to be equal to 5-6 nm, was calculated in this work. It is shown that the thickness of the surface layer is determined by one parameter – the atomic volume of a chemical element. A simple relationship between the surface energy of a metal and its melting point is obtained. All the relationships obtained are in good agreement with the experimental data.

For a solution of the problem of crystallization of metals and alloys it is necessary to take for granted that the basic construction elements in forming crystals are nanocrystals of phases. Specific interphase surface energy of a crystallization center is directly proportional to its radius. Hydrogen exerts direct impact on process of crystallization of dendritic crystals of phases.

The aim of this work was to search the colloidal systems characterized by maximal effects of water interaction with a solid surface and micro-coagulation, as well development of control methods of thixotropic properties, by addition of solid and liquid hydrophobic compounds into the colloidal systems. Water state and its thermodynamic characteristics, namely the values of free interfacial energy for concentrated colloidal systems based on hydrated blends of hydrophobic compounds (polymethylsiloxane, PMS and methylated nanosilica AM1) and hydrophilic nanosilica A-300, were studied using low-temperature 1H NMR spectroscopy and electron microscopy. It was established that the free interfacial energy of water, determining the thixotropic properties of the concentrated suspensions under condition of great hydration, is firstly affected by the structure of inter-particulate space, especially by the nanocoagulation effects and influence of a surface on the formation of the hydrogen bonds network in the adsorption layer. For the blend with A-300 and AM1 (1:1 w/w), the free surface energy of interaction with water is nearly ten times greater than that for the initial silicas alone. However, the micro-coagulation effects are poorly visible in microscopic images because these oxides are composed of similar nanoparticles. Similar effects of enhancement of the free surface energy are observed for a blend with A-300 and PMS. For this blend, the microcoagulation effect is observed in microscopic images. It is maximal for the blend prepared without strong mechanical loading. PMS has a twice greater surface area than that of A-300. Therefore, water filling voids in PMS aggregates forms clusters of smaller sizes than that bound in A-300. However, hydrophilicity or hydrophobicity is not a predominant factor determining the free surface energy of bound water. If strongly hydrated treated powders of PMS (or AM1) and A-300 are placed into a hydrophobic medium with weakly polar CDCl3 that this solvent could diffuse into hydrophobic component and displace water from narrow interparticle voids toward larger ones. However, this effect is much weaker for a hydrophilic component with A-300. These effects appear in a strong dependence of the γS value on the type of the dispersion medium for PMS and a weak dependence for A-300. The stronger the decreasing effects of a hydrophobic liquid onto the γS value, the stronger is diminution of the thixotropic properties on the composites. The blends of hydrophobic and hydrophilic powders with the bulk density < 0.2 g/cm3 are most perspective thixotropic compositions since they demonstrate the maximal values of γS and a strong microcoagulation effect. [ABSTRACT FROM AUTHOR]

Influence of the surface relaxation on the surface energy of low-index faces of alkaline metals is considered. It is shown, that compression of interplane distances is observed on friable faces (111) in all cases, and either a stretching or absence of relaxation is observed on close-packed faces (110) for Li and K. Presence of a field strengthens the surface relaxation and changes the value of the surface energy.

Dependence of the surface energy of metal thin films on the monoaxies deformation of compression and stretching has been qualitatively described. Calculations made for films of tantalum and niobium by modified electron-statistical method. The influence of deformation on the electron density of the system and the Gibbs coordinate has been demonstrated. A weak nonlinear change of the surface energy with the monoaxies deformation has been determined.

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On the bases of thermodynamic model we have obtained the ratio for the bond energy of alloy crystals. The modified electron-statistical method has reproduced size and concentration dependences of the surface energy of thin films of the transitional metal alloys.

The mathematical analysis of influence of additives of the third component (Cr, Mn, Fe, Co, Ni, Ga, Zr, In, Sn) on quantities of energies of a segregation of impurities in volume and on boundaries of grains of alloy Cu-4,35 at. % Ti is made during aging on the cellular mechanism. Calculation of enthalpies of a segregation is spent with the account of energies of interatomic and elastic interaction of atoms of a different grade. Effects of experimental researches testify, in particular, to effective accelerating influence Ni on development of cellular decay in alloy Cu-4,35 ат. % Ti and essential inhibiting action of the given process by an additive Co. On the basis of modelling calculations of enthalpies of mixture in volume and on boundaries of grains it is erected that for the specified additives distinctions in quantities of an enthalpy of mixture in volume of grains appear considerable. The carried out analysis can be taken as a principle build-ups of model of a dynamic segregation and its influence on velocity of cellular decay in threefold metal systems.

On the bases of modified electron-statistical method, we have proposed the method of calculation of the work function’s anisotropy of metallic monocrystals. The work function and surface energy had been calculated for closepacked faces of allotropy phases of 4d - and 5d - metals with bcc structure. We had demonstrated that this method gives the results, which correlate with experimental data for polycrystals.

The attempt to derive the relation for the temperature of contact melting of small-dimensional phases (nanoparticles, nanofilms) has been made with account for the A.I. Rusanov size dependence of the surface tension of nanoparticles.

The methods of limiting wetting angle and surface energy have been employed to detect the hydrolytic resistance in ceramic restoration systems - silicate feldspar baked ceramics; silicate glass-ceramics; oxide ceramics infiltrated with lanthanum aluminosilicate glass; polycrystalline oxide structural ceramics, and natural teeth. It has been shown that the synthesized polycrystalline oxide structural ceramics has prominent hydrolytic resistance, which provides it with adhesion resistance against the microbial deposits from the oral liquid. Reduced bacterial contamination at the prosthetic bed tissues helps improve the general hygiene in the oral cavity also adding stability to remote clinical outcomes thus working a positive effect on the efficiency of the restoration treatments.

It is shown that extent of modifying of an alloy is proportional to overcooling at its hardening, viscosity of fusion and interphase superficial energy of crystals of the leading phase. The key technological parameters of modifying of an alloy are the speed of its hardening, viscosity of fusion and extent of refinement from surface-active elements. Their adsorption on crystals of the leading phase interferes with modifying of an alloy.

In this paper we present calculated isothermal-isomorphic dependencies of specific surface energy ( σ ), its isochoric derivative respecting to the temperature ( σ’ ), and surface pressure ( Psf ) versus size of nano-diamond of 12C and 13C at 100K and 4300K . It is shown that ratio σ(12C)/ σ(13C) decreases at reduction of the size along both isotherms, but σ’(12C)/ σ’(13C) - increases at reduction of the size as appreciably, as temperature is lower. The ratio (13C) increases with reduction of the size as appreciably, as temperature is higher.

Expressions for the dependencies of the specific surface energy σ and its isochoric derivative with respect to the temperature (∂σ/∂T)V versus of the relative volume V/V0 of the simple matter crystal are received. It is shown that isotherm σ(V/V0) has a maximum at (V/V0)max1 to negative region: σ(V/V0) fr=0. It must cause the fragmentation of the crystal at V/V0( V/V0)frL.

Predicting quantitative characteristics of polymer surfaces wetting is one of the urgent tasks, which is to be solved at designing the systems of adhesives, coatings, printing materials, etc. The hydrophilic-lipophilic balance concept, which, however, allows only a qualitative effectiveness assessment of wetting agents is often used to solve this problem. The modified Owens-Wendt method, the theoretical basis of which allows to determine the relationship between the components of the surface tension of liquid and wetting efficiency of polymer surface with the known energy distribution is used in this paper. A practical approach, allowing to define the parameters of the surface tension of surfactants solutions, using the reference data on the components of the surface tension of liquids is proposed. It was shown that the method allows to achieve the high measurement accuracy of the specified solutions parameters and quantitatively predict the angles values of polymer surfaces wetting by liquid with the accuracy ± 4°. It was determined that solutions of anionic and nonionic surfactants are characterized by extremely low values of the polar component of the surface tension. At the same time, the values of solvent dispersion component increase at introducing these modifiers. The results are of practical importance, and can be used to develop wetting agents for the systems of polymeric adhesives, printing materials and coatings for plastics. Developing the obtained theoretical patterns will allow to take into account the influence of bi- and three-component solvent systems in the model that provides a quantitative description of such processes as dispersing highly-hydrophobic pigments and creating strong adhesion contacts in polymeric systems. [ABSTRACT FROM AUTHOR]

At Maritime University of Szczecin there are carried out research works concerning utilization of biofuels on fishing vessels. There are a lot of information about relations between atomization and fuel combustion. Initial works also indicates correlation of surface tension with atomization. This article presents results of experimental investigation of droplets distribution after determination of fuel oil surface tension. Relation between atomization quality and surface tension are analyzed. Distillate fuel oil, rapeseed oil and 10% rapeseed mixture with distillate fuel oil were used as a fuel. [ABSTRACT FROM AUTHOR]