Nickel-based composite electroplated coating

Electrolyte for deposition of a nickel-fluoroplastic composite coating was developed. The physicomechanical properties of this coating were studied.     

Kinetic analysis of photoelectrochemical hydrogen evolution over p-type silicon in acidic aqueous solutions of electrolytes

The kinetics of photoelectrochemical hydrogen evolution at p-Si single crystals in acidic aqueous solutions of electrolytes under pulse photoexcitation was studied. Despite a low stability of the silicon surface under the experimental conditions, a distinct interrelation between the characteristic time of interfacial charge transfer and stationary current was found. The determination of the characteristic transfer time does not need the detailed elaboration of generation-recombination processes in the semiconductor. The steady-state current density was shown to be determined both for the dark current and photocurrent by the surface charge density. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1724–1728, October, 2000.     

Synergistic effect in nickel-Teflon composite electrolytic coatings

The possible synergistic effect in the manifestation of the wear resistance and antifriction properties of nickel-Teflon composite electrolytic coatings was analyzed. The results of calculations of the diagnostic properties of the coatings in terms of the “concentration-wave” model are discussed in comparison with the corresponding experimental data.     

Hydrogen Evolution Efficiency at Illuminated Silicon

The change of kinetic characteristics of photoelectrochemical hydrogen evolution at p-type silicon in acid aqueous electrolyte solutions under prolonged continuous illumination is studied. It is shown that, during the transfer of full charge Q _t < 150 C/cm² through the silicon/electrolyte interface, the interrelation between the reciprocal time of the charge transfer into electrolyte and the steady-state current remains linear. In this case, a Tafel-like relation links the interfacial charge to the steady-state electrode current. Passing current through the electrode even further results, at Q _t > 350 C/cm², in breaking-down the direct relation between the current and the charge transfer time, despite the electrode's retaining high photosensitivity. The effect is probably caused by significant energy and structure distortions in the surface layer of silicon.     

Possibility of raising the deposition rate of nickel coatings from a chloride electrolyte

Conditions under which nickel coatings can be deposited from a chloride electrolyte at a high rate were studied. The mechanism of this process was suggested and experimentally confirmed. The mass-transfer rate of nickel-containing particles was determined by chronopotentiometry, with temperature raised from 20 to 50°C. The dependence of pH_s on the current density was determined. Physicochemical parameters of the coatings (microhardness, internal stresses, porosity, luster, and adhesion) were measured.     

Wear resistance of electrolytic nickel-boron alloy deposited from a chloride electrolyte

Dependence of the wear resistance of an electrolytic nickel-boron alloy deposited from a chloride electrolyte on the alloy composition, thermal treatment temperature, and specific load on friction surfaces was studied.     

Electrolyte for obtaining composition nickel coats

Stability of a chloride electrolyte for deposition of a composition nickel-polytetrafluorethylene electrolyte coating was studied, and the homogeneity of polytetrafluoroethylene distribution in the coat was determined.     

Possibility of saving silver in deposition of a multilayer copper-nickel-silver coating

Possibility of making thinner silver coatings on low-current sliding contacts in deposition of multilayer nickel-silver and copper-nickel-silver coatings from various electrolytes was studied.     

Properties of nickel-cobalt-diamond composite coating deposited from a chloride electrolyte

Effect of electrolysis modes and electrolyte composition on physicomechanical properties of nickel-cobalt-diamond composite electroplated coatings deposited from a chloride electrolyte with introduction of an ultradispersed diamond suspension was studied and the possibility of replacement of wear-resistant chromium coatings with these composite coatings was demonstrated.     

Spin Localization in Poly(3-Dodecylthiophen)/PCBM Composite

Charge carriers photoinduced in poly(3-dodecylthiophene)/([6,6]-phenyl-C₆₁-butanoic acid methyl ester) (P3DDT/PCBM) by photons with the energy of 1.88–2.75 eV were investigated by X-band light-induced electron paramagnetic resonance (LEPR). LEPR spectra were attributed to non-interacting polarons and methanofullerene anion radicals with different magnetic and relaxation parameters. A part of these charge carriers are trapped in a polymer matrix. Paramagnetic susceptibility and spin–spin relaxation of mobile charge carriers were shown to follow the activation law.