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The article provides a general overview of the production methods and applications of carbon materials with a large specific surface area. The following materials were taken as objects for the study: SK-AG-3 granular activated carbon produced by OJSC «Sorbents of Kuzbass», Kemerovo, activated cellulose fiber produced by the Krasnoyarsk Chemical Fiber Plant after carbonation, graphitization, and gas-phase activation at 900 °C in carbon dioxide current, Busofit-T carbon fabric produced by OJSC «SvetlogorskKhimvolokno», thermally expanded fluorinated graphite produced by OJSC «Siberian Chemical Combine». The porous structure of these materials was investigated by low-temperature volumetric nitrogen adsorption at the ASAP 2020 unit. Nitrogen adsorption-desorption isotherms were recorded in a relative pressure range of p/p0 = 0.05÷1.0 at 77 K. The specific surface area was estimated by the BET method based on the adsorption isotherm at p/p0 = 0.05÷0.30. The specific surface area was 485, 1241, 1156 and 290.5 m2/g for activated carbon, activated carbon fibers, Busofit-T fabric and thermally expanded graphite, respectively. The volume of mesopores and their size distribution were calculated by the Barrett-Joyner-Нalenda (BJH) method in a pressure range of p/p0 = 0.35÷0.95. The volume of micropores and their size distribution were calculated by the Horvath-Kawazoe method using the nitrogen adsorption-desorption isotherm in a relative pressure range of p/p0 = 0.00÷0.01. These methods were also used to determine the average diameter of mesopores and micropores. A comparative analysis of the results obtained was carried out. A relationship between the internal structure of the investigated materials and the porous structure properties was traced. It was shown that activated carbon, fibers, and carbon fabrics are microporous materials, and thermally expanded graphite has a mesoporous structure.

The aim of this work was to characterize the char of agricultural waste cashew nuts shells (CNS) and activated carbons prepared from CNS by physical activation method for the treatment of water. The characteristics studied are functional groups (phenol, carboxyl, and carbonyl), elemental analysis, pH and ash content. CNS from the Republic of Côte d’Ivoire were pre-treated and carbonized at 800°C. With the aid of the char obtained, three activated carbons were prepared corresponding to the following activation temperatures: 400, 600 and 700°C. The activation time was set at 30 minutes. The activating gas used is water vapor. The results showed that: the char contains no phenol (0.00 mg eq/g) and carboxyl (0.00 mg eq/g), but a quantity of carbonyl (0.8 mg eq/g) which gives it basic properties. The char and the activated carbon obtained contain 79.7 - 82.40% C; 1.2 -1.66% N; 1.2 – 1.9% H and 1.10-5 to 3.3.10-2% of the following elements: Al, B, Fe, Si, Mg, Ca, Co, Cr, Mo, Ti, Mn, Cu, Cd , Ni, Pd, V; the pH is 10,5-11,01 and ash is 5.66 - 7.31%. The specific surface area and the total volume of meso- and micropores of char obtained are respectively 3.56 ± 0.18 m2/g and 0,0047 cm3/g. The specific surfaces of activated carbons as a function of the activation temperature (400, 600, 700 °C) and the total volume of meso- and micropores are respectively: 45.3 ± 1.3; 165.7 ± 4.6; 316.6 ± 11.0 m2/g and 0.035; 0.098; 0.183 cm3/g. The adsorption-desorption isotherm of the char obtained is type IV. The adsorption - desorption isotherms of the activated carbons are of type I (Langmuir isotherm)., Ce travail a pour but de caractériser le carbonisât des coques de noix d’anacarde (CNA) et les charbons actifs (CAs) qui en sont obtenus par activation physique pour une application dans le traitement de l’eau. Les caractéristiques analytiques mesurées sont la composition élémentaire, le pH, le taux de cendre et les groupes fonctionnels (phénol, carboxyle, carbonyle). La surface spécifique et le volume total de méso - et micropores ont été également mesurés comme caractéristiques essentielles des propriétés d’adsorption.Des CNA issues de la République de Côte d’Ivoire ont été prétraitées et carbonisées à 800°C. Puis à partir du carbonisât obtenu, trois CAs ont été préparés par activation thermique aux températures de 400, 600 et 700°C respectivement. Le temps d’activation a été fixé à 30 minutes. Le gaz activant utilisé est la vapeur d’eau. Les résultats ont montré que le carbonisât ne contient pas de phénol ni de groupement carboxyles. On trouve en revanche des groupes carbonyle (0,8 mg eq/g) qui confèrent au carbonisât des propriétés basiques. Le carbonisât et les CAs obtenus contiennent 79,7 - 82,4 % de C ; 1,20 -1,66 % de N ; 1,2 - 1,9 % de H et des traces (1.10-5 à 3,3.10-2 %) des éléments suivants : Al, B, Fe, Si, Mg, Ca, Co, Cr, Mo, Ti, Mn, Cu, Cd, Ni, Pd, V. Le pH est 10,5-11,01 et le taux de cendre est 5,66 - 7,31 %. L’activation thermique a permis d’augmenter la surface spécifique des échantillons de 3,56 ± 0,18 m2/g dans le carbonisât à 45,3 ± 1,3 ; 165,7 ± 4,6 et 317 ± 11 m2/g dans les charbons actifs obtenue à 400, 600, 700°C respectivement. Les volumes totaux de méso - et micropores ont également été augmentés dans des proportions similaires.

The specific surface and porous structure of viscose-based carbon fibers produced by the Krasnoyarsk Plant of Chemical Fibers are investigated by low-temperature nitrogen adsorption using an ASAP 2020 device. The dependence of their specific surface and character of the pore-size distribution on gas-phase activation modes in the carbon dioxide stream at a temperature of 900°C is shown. It is established that the adsorption surface of carbon fibers can rise from 0.3 to 1900 m2/g during the activation. It is revealed that the prolongation of the activation time leads to an increase in the specific fiber surface owing to the appearance of numerous new micropores and the development of the microporous structure.

The effect of a titanium coating on the sorption properties of carbon textile Busofit was studied. The BET specific surface area was about ·103 m2/g before and after metallization of the fiber. The micropore volume in samples accounted for most of the total pore volume.

The results of the study of morphological changes in the carbon fibers surface of "Kulon" based on PAN fiber and of carbon textile Busofit under irradiation with helium ions with energies of the order of hundreds of electron volts are presented. Scanning electron microscopy showed a significant ion-induced change in the morphology from the smooth fiber surface to a developed surface with the corrugations, nanowalls and whiskers of submicron height.

The surface properties of carbon fiber adsorbents prepared from different starting materials and by different procedures were investigated with the aim of optimizing their pore structure. The best results were obtained with carbonized fibers: at 900°C in flowing CO2 , their specific surface was increased from 0.5 to 2000 m2 /g.