Porous anodic alumina layers were obtained by a simple two-step anodization of low purity aluminum (99.5 % Al, AA1050 alloy) in a 0.3 M oxalic acid electrolyte at 45 V and 20°C. The effect of anode surface area on structural features of nanoporous oxide and process of oxide formation was investigated. An ordered structure composed of nanostripes or nanopores was formed on the Al surface during electrochemical polishing in a mixture of perchloric acid and ethanol. This nanopattern is then replicated during the anodic oxide formation. It was found that the pore diameter, interpore distance, and porosity increase slightly with increasing surface area of the aluminum sample exposed to the anodizing electrolyte. On the other hand, a slight decrease in pore density and cell wall thickness was observed with increasing surface area of the sample. The detailed inspection of current density vs. time curves was also performed. The obtained results revealed that the higher surface area of the anode, the local current density minimum, was reached faster during first step of anodization and the increase in current density corresponding to the pore rearrangement process was observed earlier. Finally, a dense array of Pd nanowires (∼90 nm in diameter) was synthesized by simple electrodeposition of metal inside the channels of through-hole nanoporous anodic alumina templates with relatively large surface areas (4 cm 2).

The paper is dedicated to the development of effective composite coatings with the use of carbon fillers of different morphology, their research, and application in the broadband frequency range. Electromagnetic loss studies were performed according to international standards ASTM D4935, IEEE-STD-299, and the US Department of Defence standard MIL-STD 461F. The impact of hybrid carbon nanomaterial "graphene/nanotubes" on the electrophysical properties of the composite material has been analyzed. As a result, the research laboratory technologies of production of composite coating on water and non-water (alcohol) basis are developed based on the carbon fillers of various morphology and also magnetite. The shielding properties of most of the created composites are estimated in the frequency range from 50 MHz to 30 GHz. The state enterprise “All-Ukrainian center for standardization, metrology, certification, and consumers’ rights protection” (here and after “Ukrmetrteststandart”) conducted comparative tests of the developed coating (in the form of paint) with a protective coating # 842 MG Chemicals (Burlington, Ontario, Canada) based on silver microparticles. Developed water-based composites can be used for interior decoration, in the formation of electromagnetic screens, thin gradient coatings to protect people from electromagnetic radiation in the microwave range.

No abstract

Electrochemical properties and possibilities of manufacturing the anodes based on water-soluble binders such as carboxymethylcellulose (CMC) have been investigated in order to create prerequisites for development of “green” technologies for recyclability of LIBs components. In this work an advanced anode was designed. A kind of nanosized carbon coated Si composite was synthesized. The charge/discharge test reveals that the advanced anode shows a reversible capacity of 600 mAh/g. The improved performance was ascribed to the carbon shell of Si and CMC binder. The binder CMC buffers the expansion of the Si and the improved electric contact between the active material and copper current collector.

Розглянуті перспективні процеси та матеріали в таких пріоритетних напрямках прикладної електрохімії, як електрохімічні джерела струму, гальванотехніка, захист від корозії, електрохімічні сенсори, сучасні електрохімічні та споріднені технології. Стан досліджень в цих пріоритетних напрямах електрохімії в значній мірі визначає прогрес у загальному розвитку науки і техніки ХХІ століття та сприяє створенню принципово нових видів продукції та технологій. Монографія рекомендована для науковців, викладачів, аспірантів, студентів профільних закладів вищої освіти, інженерно-технічних працівників електрохімічних та споріднених виробництв.