Carbon-Carbon Composite Materials Based on Low Modulus Fabrics

Scientific research and the search for new technologies to increase the level of mechanical and high-temperature properties are ongoing. The article discusses the technology of using carbon materials, pyrolysis and impregnation with phenol-formaldehyde resins. It is shown that the proposed technology makes it possible to achieve a sufficient level of mechanical properties when using low-modulus carbon fabrics after pyrolytic treatment as a prepreg at a temperature treatment no higher than 900 K. Pillowcase and resole phenol-formaldehyde resins were used to impregnate the prepreg. The proposed technology also allows the introduction of alloying additives into the system to improve the properties. An example of the introduction of nitrogen into a composite by adding urotropine to a phenol-formaldehyde resin, which was used to impregnate the composite, is considered.

Hybrid Sorbents for Removal of Arsenic

The paper analyzes data on the removal of arsenic by sorption methods using materials that have prospects for large-scale application in water treatment. These materials include transition metal oxides in the micro- and nano-dimensional form, including those in the composition of composite materials with inorganic matrices, or hybrid sorbents in the composition with polymer resins or natural biopolymers. Examples of the use of composite (hybrid) sorbents for the removal of arsenic from solutions with low concentrations (at the level of MPC) are given. The objective of this article was to sum the up-to-date information about the most important features of chitosan-containing and chitosan-carbon materials we developed in view their use in arsenic removal processes at low concentrations to concentrations that meet WHO requirements. The paper presents data on the sorption properties of Mo-containing activated carbon fibers and chitosan-carbon composite materials towards arsenic (V) when it is extracted from bidistilled and tap water under static and dynamic conditions. The factors of the different behavior of the sorbents depending on the form of a biopolymer deposited on the fiber and the stability of the sorbents during the sorption of arsenic are discussed.

Study of the phase transition ability of coal tar pitch and their coke products under the influence of temperature used to synthesise carbon composite materials

Using differential scanning calorimetry and thermogravimetric analysis showed the marking temperature of coal tar pitch is 107.8°C. The thermal decomposition of the pitch is divided into three main stages, corresponding to three phases α, β, γ, with a coke yield of 47% at 800°C. The change in the XRD diagram showed a clear transition from the amorphous state of carbon to the highly ordered crystalline structure of graphite after treatment at 2,200 and 2,700°С. The purity of the pitch sample and the structure of the CCC carbon-carbon composite material after heat treatment at 2,700°C were studied using scanning electron microscopy and energy-dispersive X-ray spectroscopy methods. The results showed that after heat treatment, the C content in the sample reached more than 99.5%, and the coke residues after graphitization were bound and connected to the carbon fabric into a mass of graphite material.

INFLUENCE OF THE PYROLYTIC COMPACTION PROCESS ON THE PHYSICAL AND MECHANICAL PROPERTIES OF HIGH-DENSITY CARBON-CARBON COMPOSITE MATERIALS BASED ON PITCH MATRICES

The efficiency of the pyrolytic carbon compaction process by decomposing methane in samples of a carbon-carbon composite randomly reinforced with discrete high-modulus (graphitized) carbon fibers with different densities is investigated. The analysis of the test results of samples for determining the compressive strength, determining the densities of samples after compaction with pyrocarbon and after compaction by impregnation and carbonization under pressure is carried out. Scanning electron microscopy (SEM) was used to study the structure of material samples with different initial density values.

Investigating process technologies for production of carbon composite material antennas for maritime radio communication systems

The paper is dedicated to studying manufacturing prospects of antenna devices from carbon composite materials and suggests technical solutions aimed at water transportation radio communication needs. Principal physical parameters of the carbon composite material used in manufacture and subsequent studies of antenna specimens were compared to those of metals. Peculiarities of manufacturing carbon composite antenna devices have been considered. Antenna specimens were experimentally studied for their electromagnetic characteristics, while their digital copies were studied in simulation. Similarities are pointed out between the main characteristics of composite antennae and their metal analogs. Efficiency of proposed technical solutions and antenna building technologies are demonstrated for application of carbon composite antennas in marine radio communication.

Flexible Carbon Based Nanoelectronics with Printing Approaches

This review construes diverse upcoming technologies and significant physical concerns in polymer-carbon composite materials nanoelectronics. There are numerous cases from mechanically flexible and portable thin-film transistors based on carbon materials, flexible and stretchable energy storage applications, flexible sensors applications to flexible solar cells. In various systems, the mechanical structure design is as essential as circuit structure designing. Recent studies in flexible carbon materials-based nanoelectronics suggest that in addition to the advancement, multidisciplinary approaches such as 3D printing, incorporating almost every area of the conventional research, in materials science, chemistry, physics, and engineering fields such as electrical, electronic and mechanical.