Alexander N. Minaev

Charge transfer at the antiscale composite layer-electrolyte interface

Properties of composite coatings based on oxide layers formed on a titanium surface using the plasmic electrolytic oxidation method and processed using Forum® superdispersed polytetrafluorinethylene were investigated. A combination of electrochemical impedance spectroscopy, differential thermal analysis, and thermal gravimetry methods allowed one to establish the change of the surface state as a result of heating that determines the charge transfer mechanism at the heterostructure-electrolyte phase interface and the difference in the thermodynamic stability of the temperature fractions of the employed polymer.

Composite coatings formed by plasma electrolytic oxidation

The prospects of using organic and inorganic nanosized materials are shown in the process of the formation of surface multifunctional composite protective layers obtained using plasma electrolytic oxidation on metals and alloys.

Composite polymer-containing protective layers on titanium

The influence of treating the coatings obtained by plasma electrolytic oxidation (PEO) and various fractions of polytetrafluoroethylene on the state of the surface of formed composite layers has been studied by electrochemical impedance spectroscopy, differential thermal analysis, and thermogravimetry. Differences in the resistance to charge transfer at the oxide heterostructure/electrolyte interface for various composite layers have been found. The obtained data significantly enlarge and complement the possibilities of directly forming protective coatings, including antiscale ones, on the surface of titanium alloys operating in aggressive media at high temperatures.

Effect of conditions of treatment with superdispersed polytetrafluoroethylene on properties of composite coatings

A purposeful selection of the number of layers and the treatment temperature depending on the used fraction of superdisperced polytetrafluoroethylene (SPTFE, the Forum trademark) provides a maximum penetration of the polymer into pores and the formation of a uniform and continuous film on the surface. This information is of crucial importance for obtaining composite, including multifunctional, protective (antiscale and anticorrosion) layers on titanium products that operate under different temperature conditions in aggressive chloride-containing environments.

Morphological Features and Electrochemical Properties of the Hydrophobized Sealed PEO-Coatings on Al Alloy

The developed methods of formation and results of the study of the hydrophobic layers on aluminum alloy, previously subjected to plasma electrolytic oxidation (PEO), boiling in bidistilled water, and additional treatment (either in ethanol solution or under UV-radiation in the presence of ozone plasma) with subsequent deposition of the hydrophobic agent (methoxy-{3-[(2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluoroctyl) oxy] propyl}-silane solution in decane) have been described. It was found, that the formed composite layers possess hydrophobicity (contact angle higher 155o) and high anticorrosion properties (the impedance modulus (|Z|f = 0.01 Hz) ranges from 1.5·108 to 1.7·108 Оhm·cm2 depending on treatment procedure).

Composite layers as means of lowering the intensity of scale deposition on elements of power units of ships

The influence exerted by composite layers formed by microarc oxidation with subsequent treatment with polymers (ultradispersed polytetrafluoroethylene and polytrifluorochloroethylene) on the intensity of salt deposition was studied.

Facile synthesis of nanostructured transition metal oxides as electrodes for Li-ion batteries

At all times, energy storage is one of the greatest scientific challenge. Recently, Li-ion batteries are under special attention due to high working voltage, long cycle life, low self-discharge, reliability, no-memory effect. However, commercial LIBs usage in medium- and large-scale energy storage are limited by the capacity of lithiated metal oxide cathode and unsafety of graphite anode at high-rate charge. In this way, new electrode materials with higher electrochemical performance should be designed to satisfy a requirement in both energy and power. As it known, nanostructured transition metal oxides are promising electrode materials because of their elevated specific capacity and high potential vs. Li/Li+. In this work, the perspective of an original facile technique of pulsed high-voltage plasma discharge in synthesis of nanostructured transition metal oxides as electrodes for lithium-ion batteries has been demonstrated.