The use of carbon nanotubes to create materials that absorb electromagnetic radiation and electrodes of supercapacitors

Abstract

Carbon nanotubes are effective nanomodifiers – providing the formation of a variety of thermal and electrophysical properties in composite materials. The functional purpose of composite materials determines the type and concentration of carbon nanostructures. The use of carbon nanostructures in polymer composites intended for electromagnetic shielding and electrode materials of supercapacitors is a promising direction in modern materials science. The method of manufacturing a radio-absorbing composite material included impregnation of a polyurethane foam billet – an aqueous composite suspension consisting of water, an acrylic copolymer, and carbon nanotubes "Taunit-MD". Structural studies of carbon nanotube samples were performed using transmission and scanning electron microscopy. To do this, PAM and SAM studies were performed using a HitachiH-800 electron microscope with an accelerating voltage of up to 200 Kev. For research purposes, electrodes with an area of 2 cm2 were made from carbon materials. Active mass was prepared from a carbon material and a binder, polivinildenftorid. Show PEM and SAM micrographs for samples of carbon nanotubes with the commercial name "Taunit-M". In this case, carbon nanotubes are characterized by smaller thicknesses in the range of 10-20 nm with a preferred average size of 12-15 nm. The structure of the tubes is very defective. The thickness of the tubes varies in some areas (not exceeding hundreds of nm) by more than 2 times. Carbon nanotubes have an irregular shape-there are processes, bends. The analysis of the obtained results allows us to conclude that the characteristic of the reflected EMI signal demonstrated by the pyramidal RPM is close in its values to that of the free space. At the same time, in comparison with the free space, there is a slight weakening (3-4) dB of the reflection coefficient. Carbon nanotubes MD has characteristics that exceed the carbon fabric "busofit" in terms of specific mass capacity, but inferior to it in terms of specific surface capacity. In addition, this advantage completely disappears at high current densities, which may be the result of a closed macrostructure and requires further optimization of the electrode manufacturing technology