English English

Zaytsev N.K.

Doctor of Chemical Sciences (Advanced Doctor), Associate Professor, Moscow Technological University

NANOPERFORATION TECHNOLOGY AND FUNCTIONAL PROPERTIES OF COPPER STRUCTURED MATERIALS IN THE PROCESS OF GLUCOSE ANODIC OXIDATION

, , , ,
 60-69 p.
Abstract
The paper presents an original technology for the synthesis of nanostructured copper electrodes by the method of replicas from metallic aluminum nanomatrices on a pilot high-voltage galvanic installation. The technological scheme used makes it possible to carry out the process of continuous high-voltage microplasma perforation of a metal tape with the formation of nanopores of a given size in the range from 20 to 500 nm at a variable voltage. To study the received replicas, a series of indicator electrodes with a working surface made of replica material was created. Cold rolled copper foil was used as a reference material for the electrode. The visible area of the working surface of the manufactured electrodes was examined using a scanning electron microscope. By the method of cyclic voltammetry, the coefficient of increase in the specific surface area was determined by increasing the peak area corresponding to the reduction of the surface film of copper oxide formed on the surface of the copper electrode in an alkaline medium at positive potentials. For a smooth copper electrode, the surface area was 0.071 mm2. For a nanostructured electrode of the same size, the total surface area was calculated with respect to the ar-eas of current peaks corresponding to the reduction of the surface film of copper (II) oxide on the surface of a mas-sive copper electrode and a nano-porous copper electrode. It was found that the catalytic activity, estimated by the magnitude of the current associated with the oxidation of the model substrate – glucose, is approximately 10 times higher than the increase in activity due to the total surface of copper. The anomalous catalytic effect is discussed from the point of view of increasing the local electric field strength due to the high curvature of the surface of nan-ofibers and from the point of view of changing the conditions of diffusion of the substrate to the electrode surface due to nanostructuring.
PDF

APPLICATION OF A DYNAMIC FILTRATION UNIT WITH A MODIFIED TITANIUM FILTER FOR ELECTROLYTE PURIFICATION IN A HIGH-VOLTAGE GALVANIC SYSTEM

, , ,
 13-21 p.
Abstract
The development of functional nanodisperse materials based on porous template matrices is an urgent problem in the design of new devices in the processes of electrolysis of generation of "green" hydrogen, to increase energy saving of alternative energy sources, highly sensitive sensors for chemical technology, as new catalysts for afterburning automobile exhaust, in micro- and nanoelectronic devices. In this regard, the development of technology for the production of such materials, as well as studies of the relationship between the structure and catalytic properties of nanofilament matrix synthesis materials, seem relevant. A method of dynamic filtration of solutions using self-cleaning filters with continuous high-voltage processing of aluminum template matrices is proposed. Purification of aqueous solutions consists in the deposition of suspended aluminum salts on the working surface of titanium filters modified with an organofluorine component. The undoubted advantage of the proposed approach to the filtration process is the possibility of continuous removal of aluminum salt sediment from both the outer and inner surfaces of modified titanium filters due to a combination of cavitation created by built-in ultrasonic emitters and rotation of filter elements. The rotation of the filter elements allows you to direct the flow of liquid almost perpendicular to the flow passing through the filter. As a result, a tangential filtering mode is implemented, which prevents clogging of the filter. In addition, when the filter elements rotate, a partial transfer of torque to the liquid is carried out, due to which the liquid swirls around the filter elements. The swirling of the liquid causes a centrifugal effect of displacement of aluminum salts from the liquid layers adjacent to the filter elements, preventing clogging of the filter. The proposed filtration method for high-voltage electroplating of an aluminum matrix provides voltage and current density stabilization and the formation of ordered cylindrical nanoscale structures with a high aspect ratio.
PDF

DETERMINATION OF GLUCOSE IN AQUEOUS SOLUTIONS BY VOLTAMMETRY AT THE COPPER QUASIMICROELECTRODE

, , , , ,
 38-44 p.
Abstract
Development of new sensors for detecting substances in different environments is now of great interest. Voltammetry methods, used in this article, allow one to carry out analysis in the field with almost no sample preparation. This study was carried out to investigate possibilities of quantitative glucose determination on copper quazimicroelectrode in aqueous solutions, including human blood. Process of preparation of copper indicator quazimicroelectrode with effective area consisting of ensemble of copper wires is described in this article. Glucose determination technique in aqueous solutions and the results of testing this electrode in quantitative determination of glycose in human blood are reported. The comparison of the results of investigated copper sensor with reference sensor is carried out. Statistically processed results of glucose determination are described. Copper advantages as electrode material are discussed. Designed electrode can find application in medical analysis laboratories and port-able devices for glucose determination in the field.
PDF