The paper presents the research results on the colorimetric behavior of impregnated fibrous chemisorbents (IFCS-I) of acid gases with visual identification of the dynamic absorption capacity “response” moment during the absorption of sulfur dioxide. Chemisorbents were obtained by impregnation of fibrous carriers by N-containing organic bases aqueous solutions with adding acid-base indicators (Ind). IFCS-I based on hexamethylenetetramine (IFCS-HMTA-I) and polyethylenepolyamine (IFCS-PEPA-I), as well as IFCS-MEA-EDTA-I based on monoethanolamine (MEA) and the disodium salt of ethylenediaminetetraacetic acid (EDTA) were used. The change specificity of colorimetric functions of indicator impregnated fibrous chemisorbents during their absorption of SO2 is revealed. IFCS-I original samples color significantly depends not only on the structure of Ind, but also the nature of amines (MEA, HMTA and PEPA), which are part of them. The color of the “response” samples of IFCS-MEA-EDTA-I, IFCS-PEPA-I and IFCS-HMTA-I, differ from the same properties of Bronsted acids aqueous solutions. The color change of azo-indicators occurs due to redox reactions with sulfite compounds. PEPA molecules and their ammonium cations in the composition of IFCS-I stabilize azo-indicators to these redox transformations.

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The samples of the solid component of welding aerosols (SCWAs) formed in the electric arc plasma in the process of steel welding by electrodes of Ukrainian manufacture (ANO-4, ANO-21, UONI 13/55, and TsL-11,) differed in their chemical composition. The samples were characterized by X-ray phase analysis, IR spectroscopy, and water vapor ad/desorption. The results obtained allow suggesting the influence of a phase composition on the structuraladsorption properties of SCWAs.

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This paper summarizes the data on the development of import-substituting impregnated This paper summarizes the data on the development of import-substituting impregnated fibrous chemisorbents (IFCS) intended for equipping gas cleaning equipment and personal respiratory protection equipment against gaseous toxicants of various chemical nature. To obtain IFCS of the basic gases (ammonia, organic amines), aqueous solutions of polybasic acids (citric, tartaric and hydroxyethylenediphosphonic) are used as impregnating reagents. IFCS absorb toxicants due to neutralization reactions. The absorption of ammonia and amines of IFCS obtained by impregnation of fibrous carriers (FC) with aqueous solutions of 3d-metals (Ni2+, Co2+ and Cu2+) salts occurs due to complex formation reactions. To obtain IFCS of acidic gases, aqueous solutions of sodium carbonate and urotropine (HMTA) containing structuring additives were used. Impregnating aqueous solutions based on monoethanolamine (MEA) and polyethylenepolyamine (PEPA) have also been developed using their non-volatile derivatives with a higher molar mass. A significant improvement of the IFCS protective characteristics was achieved by introducing of various modifying additives – promoters into the composition of these solutions. Single-layer IFCS -ampholytes (IFCS-A) for respiratory purposes have been developed, which depending on the circumstances are able to absorb both acidic and basic gases (vapours), for example SO2 and NH3. Impregnation solutions include complex compounds of 3d-metals (Ni2+, Co2+ and Cu2+) with MEA, ethylenediamine, HMTA and PEPA at various molar ratios of components or buffer mixtures based on polybasic acids and organic bases (MEA and PEPA) of medium strength salts. Chemisorbents for acidic and/or basic gases (IFCS-I, IFCS-AI) have been developed, the moment of “response” of the dynamic absorption capacity of which can be visually determined by the change in color of the gas mask elements during the “breakthrough” of the sorbate, obtained by impregnating of FC with solutions containing acid-base indicators.

⎯The reaction products formed in the SO 2-L-H 2 O-O 2 systems (L is n-propylamine, n-butylamine, tert-butylamine, n-heptylamine, n-octylamine, aniline) were isolated and identified as "onium" salts [n-C 3 H 7 NH 3 ] 2 SO 4 , [n-C 4 H 9 NH 3 ] 2 SO 4 , [t-C 4 H 9 NH 3 ] 2 SO 4 , [n-C 7 H 15 NH 3 ] 3 SO 4 (HSO 4), [n-C 8 H 17 NH 3 ] 3 SO 4 (HSO 4), and [C 6 H 5 NH 3 ] 2 SO 4. The products were characterized by elemental analysis, IR and Raman spectroscopy, mass spectrometry, and thermogravimetry.

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The review is devoted to non-woven sorption-filtering materials (NSFM) widely used equipment for gas cleaning from toxic gaseous and vaporous substances. The use of ion-exchange fibrous materials (IFM) as NSFM and the peculiarities of their preparation and structure have been analyzed. A lot of attention is paid to the mechanisms of chemisorption processes using IFM and to the role of water in their successful implementation. Individual options and some regularities of fibrous anionites, cationites, and polyampholytes interaction due to exchange reactions, neutralization, reduction-oxidation, complexation and precipitation with gaseous and vaporous substances are considered on specific examples.