ВведениеУглеродные волокна (УВ) являются одними из наиболее важных и интересных материалов, которые применяются в различных отраслях промышленности, что обусловлено уникальным комплексом физико-химических характеристик, которыми они обладают.Высокая сорбционная способность и химичес-кая стойкость УВ позволяют использовать их при УДК 661.66 : 616.477 DOI dx.doi.org/10.17073/1997УДК 661.66 : 616.477 DOI dx.doi.org/10.17073/ -308X-2015 Влияние режимов активации на удельную поверхность и развитие микропористой структуры углеродных волокон на основе вискозы Методом низкотемпературной адсорбции азота на приборе ASAP 2020 проведены исследования удельной поверхности и по-ристой структуры углеродных волокон на основе вискозы производства Красноярского завода химических волокон. Показана зависимость величины их удельной поверхности и характера распределения пор по размерам от режимов газофазной акти-вации в токе диоксида углерода при температуре 900 °С. Установлено, что при активации адсорбционная поверхность угле-родных волокон может вырасти от 0,3 до 1900 м 2 /г. Выявлено, что увеличение времени активации ведет к повышению удель-ной поверхности волокон за счет появления большого количества новых микропор и развития микропористой структуры.Ключевые слова: углеродные волокна, активация, удельная поверхность, сорбционная емкость, пористая структура, мик-ропоры. Gorina V.A., Cheblakova E.G.Influence of activation modes on the specific surface and development of a microporous structure of viscose-based carbon fibers Specific surface and porous structure of carbon fibers based on viscose produced by the Krasnoyarsk Plant of Chemical Fibers are investigated by low-temperature nitrogen absorption using an ASAP 2020 device. The dependence of their specific surface and character of the pore-size distribution on the modes of gas-phase activation in the carbon dioxide stream at 900°C is shown. It is established that the adsorption surface of carbon fibers can grow from 0,3 to 1900 m 2 /g in the course of activation. It is revealed that an increase in the activation time leads to an increase in the specific surface of fibers due to the appearance of numerous new micropores and development of the microporous structure.Keywords: carbon fibers, activation, specific surface, sorption capacity, porous structure, micropores.
The article proposes using the agricultural waste of Cashew Nuts Shells (CNS) from the Republic of Côte d’Ivoire to produce activated carbon used in water treatment by physical activation. Washed and crushed CNS was carbonized at 800 °С. The obtained crushed and charred CNS was physically activated with water vapor within the temperature range of 400 to 700 °С. Specific surfaces (SBET) and porous structures of obtained activated carbon samples were investigated by low-temperature nitrogen absorption using X-ray diffraction (phase) analysis. The results showed that an increase in the activation temperature with a fixed activation time leads to larger material specific surface, microporous structure development and higher total volume of mesoand micro pores of activated carbons obtained. The X-ray phase analysis results demonstrated that the degree of graphitization, interlayer spacing and crystallite size change insignificantly. It was shown that CNS can be used for activated carbon production that is not inferior by its sorption properties to analogues currently used for water purification.
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 mésoet 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, 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 m 2 /g dans le carbonisât à 45,3 ± 1,3 ; 165,7 ± 4,6 et 317 ± 11 m 2 /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. MOTS-CLÉS : coque de noix d'anacarde, carbonisât, charbon actif, activation physique, groupe fonctionnel, analyse élémentaire, adsorption, surface spécifique, isotherme, République de Côte d'Ivoire ABSTRACTThe 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][6][7][8][9][10][11]. The specific surface area and the total volume of meso-and micropores of char obtained are respectively 3.56 ± 0.18 m 2 /g and 0,0047 cm 3 /g. The specific surfaces of...
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.
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