O. Yu. Gorobets

Liquid-liquid phase separation occurring under the influence of inhomogeneous magnetic field in the process of the metal deposition and etching of the magnetized ferromagnetic ball

Liquid-liquid separation near a steel ball surface during etching and deposition processes in crossing gravity and magnetic field was investigated here both experimentally and theoretically. The influence of the Earth gravitation on the shape of the interface between the two quasi-stationary liquid phases in an electrolyte with different magnetic susceptibilities was experimentally observed. The shape of the interface is described theoretically based on the equation of the balance of osmotic, magnetic, and hydrostatic pressures in the Earth’s gravity. The impact of Earth’s gravity on the shape of the interface in electrolyte is described theoretically for the first time.

Magnetophoretic potential at the movement of cluster products of electrochemical reactions in an inhomogeneous magnetic field

An electric field arises from the influence of a nonuniform static magnetic field on charged colloid particles with magnetic susceptibility different from that of the surrounding liquid. It arises, for example, under the influence of a nonuniform static magnetic field in clusters of electrochemical reaction products created during metal etching, deposition, and corrosion processes without an external electric current passing through an electrolyte near a magnetized electrode surface. The corresponding potential consists of a Nernst potential of inhomogeneous distribution of concentration of colloid particles and a magnetophoretic potential (MPP). This potential has been calculated using a thermodynamic approach based on the equations of thermodynamics of nonequilibrium systems and the Onsager relations for a mass flow of correlated magnetic clusters under a gradient magnetic force in the electrolyte. The conditions under which the MPP contribution to the total electric potential may be significant are discussed with a reference to the example of a corroding spherical ferromagnetic steel electrode.

Effect of a magnetic field on the etching of steel in nitric acid solutions

The effect of a static magnetic field on the chemical etching of steel in nitric acid solutions was studied. It was demonstrated that the field substantially promotes the process of etching because of the magnetohydrodynamic intensification of mass transfer, the limiting stage of steel dissolution in nitric acid solutions.

Magnetic dipole interaction of endogenous magnetic nanoparticles with magnetoliposomes for targeted drug delivery

Dynamics of magnetoliposomes binding to the tumor cells and the efficiency of their recognition for targeted drug delivery is largely determined by physical interaction. In this paper we assess the strength of magnetic dipole interaction that occurs between endogenous magnetic nanoparticles in tumor cells and exogenous magnetic nanoparticles as a component of magnetoliposomes, and compare it with the forces of specific binding of the antigen-antibody complex. To assess the strength of magnetic dipole interaction the model of chains of identical particles was used, and an order of magnitude, 10−9 N, was obtained. Thus, the indicated force has an order of magnitude close to the forces of specific binding, and even more. The force of magnetic dipole interaction between a magnetically marked dosage form and tumor cells is virtually the additional specific binding force — “passive targeting” for targeted drug delivery in consequence of the fact that tumor cells tend to contain the number of biogenic nanoparticles of magnetite (Fe3O4) by an order of magnitude greater than normal.

Influence of magnetostatic fields of a ferromagnetic substrate on the electrodeposition of nickel dendrites

The influence of the magnetic state of a ferromagnetic wire substrate on the morphology of deposited nickel obtained by electrolysis has been studied. It has been demonstrated using statistical analysis that in the course of nickel electrodeposition without external magnetic field the dimensional characteristics of the arising dendritic structures are affected significantly by the residual magnetization of the substrate. When in the course of Ni electrodeposition even a weak dc magnetic field is applied perpendicularly to the wire axis, nearly identical structures are formed; that is, the system “forgets” its previous magnetic state. The magnetic properties of the substrate were visualized using powder patterns.

Oscillating Dependence of the Etched Steel Mass on the External Magnetic Field

The self-oscillating process of steel etching in a weak electrolyte solution (nitric acid) was studied as a function of the external magnetic field. The dominant feature of the process is its enhancement for most values of the external magnetic field from a chosen range. It was shown that the dependence of the etched steel mass on the magnetic field is oscillating and the corroded surface in the magnetic field is two-component.

Stationary flows of liquid in the vicinity of the small ferromagnetic particles in permanent homogeneous magnetic fields

The phenomenon of stationary flow origin is investigated in solutions of electrolytes near small ferromagnetic particles, having various shapes, under influence of an external permanent homogeneous magnetic field. Dependence of velocity of the flows on the size of needle and ball shaped ferromagnetic particles is represented in the paper.

Singular optics of spin waves in a two-sublattice antiferromagnet with uniaxial magnetic anisotropy

Based on exact 3D solutions of the Landau-Lifshitz equations in a two-sublattice antiferromagnet with uniaxial magnetic anisotropy, the existence of nonlinear spin waves with singular points on the wavefront is predicted. These waves are spin-wave analogs of optical singularities.

Liquid-liquid phase separation and cluster formation at deposition of metals under inhomogeneous magnetic field

The formation and dynamic of expansion and deformation of the liquid-liquid interface of an electrolyte at deposition of metals at the surface of the magnetized steel ball is considered in this paper. The electrochemical processes were investigated in an external magnetic field directed at an arbitrary angle to the force of gravity. These processes are accompanied by the formation of effectively paramagnetic clusters of electrochemical products – magnions. Tyndall effect was used for detection of the presence of magnions near the magnetized steel electrode in a solution. The shape of the interface separating the regions with different concentration of magnions, i.e. different magnetic susceptibilities, was described theoretically based on the equation of hydrostatic equilibrium which takes into account magnetic, hydrostatic and osmotic pressures.

Intensification of biosorption of copper ions from solution by the yeast Saccharomyces cerevisiae in magnetic field

We studied the possibility of intensification of biosorption of copper ions by the yeast Saccharomyces cerevisiae 1968 from a copper sulfate solution by immersing a metal 80-rod headpiece into the solution and applying an external magnetic field. The field was parallel or perpendicular to the axes of headpiece rods. It was shown that intensification of extraction of copper ions at various geometries of the system differed insignificantly and that copper ions were extracted from the solution via biosoprtion and cementation at the metal headpiece.