Numerical computer calculation of distribution of similar point charges at the dielectric surface

Results of numerical calculation of the distribution of similar point charges over a uniformly charged dielectric plane are presented for different surface charge densities and surface temperatures. It is shown that, in the case of the surface charge density ranging from 2 × 10⁻⁶ to 7 × 10⁻⁵ C/m² and temperatures ranging from 300 to 800 K, the Lindemann criterion is fulfilled for the average deviation of the point charge from the equilibrium position, and the collection of point charges at the dielectric surface can be regarded as a 2D Coulomb crystal.     

Study of protein coatings cross-linked via the free-radical mechanism on magnetic nanoparticles by the method of spectral and fluorescent probes

Magnetite nanoparticles have been obtained with stable coatings formed from bovine and human serum albumins. The coatings are fixed by free-radical cross-linking of the proteins with the use of their ability to form interchain covalent bonds under the action of free radicals, which are generated with participation of transition metals present on nanoparticle surface. The method of spectral and fluorescent probes has been employed for the first time to describe the properties of coatings with the use of various dyes. It has been shown that, when studying the adsorption and free-radical cross-linking of proteins on nanoparticles, it is reasonable to use polymethine and squarylium dyes for estimating the functional properties of the proteins forming the coatings. It has been found that as many as 50% of molecules forming an albumin coating crosslinked via the free-radical mechanism retain their capability of bonding to a fluorescent dye. It has been concluded that the proteins occurring in the structure of the coatings retain their functional properties.     

Spectral and kinetic investigation of interaction of 3,3′-diethyl-9-chlorothiacarbocyanine perchlorate with DNA

Interaction of the meso-substituted carbocyanine dye 3,3′-diethyl-9-chlorothiacarbocyanine (DCTC) perchlorate with DNA in phosphate buffer solutions (pH 7) was studied by spectral and kinetic methods. It was shown that the dye mainly exists in the cis-isomer form in water and aqueous-alcoholic solutions. The interaction with DNA leads to the formation of a trans-DCTC complex, which gradually (over a few tens of minutes) converts into the complex of the dye cis-isomer. It was revealed that the reactant concentration and ionic strength of solution have a considerable effect on the kinetic characteristics of trans-cis-reorganization of DCTC complexes, thus indicating a complex character of the process.     

Synthesis of transparent vertically aligned TiO2 nanotubes on a few-layer graphene (FLG) film

Novel transparent 1D-TiO(2)/few-layer graphene electrodes are realised by the anodic growth of vertically aligned TiO(2) nano-tubes on a few-layer graphene film coated on a glass substrate.     

Proton conductivity of borate glass of the Me<Subscript>2</Subscript>O-B<Subscript>2</Subscript>O<Subscript>3</Subscript> (Me = Na,Ag, Tl) system

The temperature-concentration dependences of glass conductivity in the Na₂O-B₂O₃, Ag₂O-B₂O₃, and Tl₂O-B₂O₃ systems are studied. The nature of charge carriers in glass of these systems is revealed experimentally and their dependence on the concentration is studied. Based on the methods of Hittorf, Tubandt, Hebb-Liang-Wagner, and also on the fulfillment of Faraday’s Laws, it is shown that in glass of the Na₂O-B₂O₃ system with [Na₂O] < 15 mol %, the protons take part in the transport of charge in addition to sodium ions. The unipolar sodium conduction is attained at [Na₂O] > 17 mol %. In glass of the Ag₂O-B₂O₃ system, the conduction is associated with the migration of both silver ions and protons. For Ag₂O concentrations from 15 to 22.5 mol %, the transport numbers of silver ions vary in a range from 0.45 to 0.53 and are virtually independent of the Ag₂O content. In glass of the Tl₂O-B₂O₃ system, the charge transfer is performed exclusively by protons. The contribution of the electronic component into the conductivity of glass in the systems studied does not exceed 0.01%. An interpretation of the temperature-concentration dependences of conductivity is put forward.     

Electrochemical Study of Glasses in the System Na2O-B2O3

The steady-state electrical conductivity and microhardness of glasses in the system Na₂O-B₂O₃ was studied. IR spectroscopy was applied to determine the content of impurity hydrogen in the glasses studied.     

Phase equilibria in the system fullerene C60-hexane-o-xylene-dimethylformamide

Phase diagrams in ternary liquid systems hexane o-xylene DMF were studied at 298.15 333.15 K. Critical points in these systems were determined. The fullerene C₆₀ distribution in the ternary liquid systems with constant and variable compositions of two organic phases was studied at variable fullerene concentration.