661.18:667.4 and O. S. AlchanovaThe kinetic characteristics of synthesis and hardening of the polymer cation-exchange matrix in a carbon fibre were investigated, the effect of the chemical nature of the fibre filler on the structure of the ionexchange matrices formed was noted, and the possibility of purposeful regulation of their structural characteristics was demonstrated. It was shown that the chemisorbents developed can be used in treatment of wastewaters to remove chloride and sulfate ions. Chemisorption blocks with combined Polikon CCFM (with anion-and cation-exchange polymer matrices) were recommended for more efficient treatment.The consumption of a significant amount of tap water by industry, its reaction with different substance sin the manufacturing cycle, and in the final analysis, pollution, makes it necessary to treat the water before discharging it. Investigators are focusing great attention on selection of the treatment method as a function of the requirements for the quality and degree of treatment of the water. Carbon fibres and composite chemisorbents made from them are considered the most effective materials capable of solving the most complex water treatment problems.Due to ordering of the structure of carbon fibres (CF) made from acrylonitrile copolymers, the unit of their volume contains a large amount of meso-and micropores positioned perpendicular to the axis of the fibre and accessible from the outer surface, which ensures their high kinetic activity with respect to sorbed substances in comparison to granulated carbon sorbents [1]. The high chemical resistance (to acids and bases) and thermal stability (up to 350°C in air) and the relatively high selective and sorption characteristics of CF make their use feasible as fillers for composite chemisorptions fibre materials (CCFM).Carbon fibres were used in the previous study to increase the performance properties of Polikon chemisorbents as the fibre base for synthesis and formation of a cation-active polymer matrix. The studies showed (Fig. 1) that the rate and degree of wettability with a hydrophilic impregnating composition have a smaller effect on the CF in comparison to PAN fibre, which is due to the hydrophoby of the graphitized structure.In view of the features of the structure and chemical nature of the fibre filler, the effect of CF on the kinetics of synthesis and hardening of the cation-exchange matrix was investigated by differential scanning calorimetry. Synthesis and formation of the polymer matrix in carbon fibres take place with a higher initial rate. The overall heat effect of the polycondensation reaction |ΔH| (Table 1) increased and the maximum was identified in the low-temperature region (45°C). Hardening takes place with an increase in the heat effect by 1710 J/g, which indicates the formation of a more thickly crosslinked spatial structure of the polymer matrix.Manufacturing methods and process parameters for manufacturing Polikon CCFM on CF were developed based on an analysis of the results of the studies, pilot-labora...

Scanning electron microscopy was used to determine the effect of the molding pressure in the hardening stage on the surface morphology of membranes and a decrease in the size and number of macropores was found. The electrochemical properties were determined, the surface and bulk resistance was quantitatively estimated, the causes of the increase in them was explained, and the elemental composition of hydrophilic and hydrophobic sections of the materials was investigated.New technologies and materials have totally transformed human activity -from industry to medicine and the home. However, together with the colossal advantages, new problems have also arisen and require the steady attention of world scientists. These problems unconditionally include environmental problems related to accumulation of large amounts of wastes and the acute shortage of drinking water. The importance of membrane technology, primarily as a technology capable of building a bridge across the precipice separating industry and the environment, has recently increased. Membrane technology in the Russian Federation currently has the status of critical and covers scores of critical technologies. The importance of membrane technology is difficult to overestimate, and there are areas where it has no competitors.One type of membrane widely used in industry is the polymer ion-exchange membrane; these membranes are multiphase systems that combine polar and nonpolar components. Polikon membranes were developed in the Department of Chemical Engineering at Engels Technological University. They are fabricated by polycondensation filling, where the phenol-sulfo cation-exchange matrix is synthesized and formed in the structure and on the surface of synthetic fibres (polyacrylonitrile, viscose, carbon, and their composites). We investigated the effect of the conditions of formation of the polymer ion-exchange matrix on the structure and functional properties of the membranes: the features of the pore structure, specific surface area of the nanopore structure of the ion exchanger phase, exchange capacity, and physical properties.Pilot-laboratory batches of Polikon 0, Polikon 1, Polikon 2, Polikon 3, Polikon 4, and Polikon 5 materials were fabricated with previously developed technology. The molding pressure in fabricating them was 10 -1 , 1, 5, 10, 12, 15, and 20 MPa, respectively, with a 15-min hardening time. The qualitative and quantitative composition of the composites was identified by spectroscopy in an INCA Energy analytical attachment on a scanning electron microscope.The experiment showed that the composition of the composites is represented on average by 61% carbon, 35% oxygen, and 4% sulfur. Two basic regions were examined in the analysis performed at different points with an investigated section size of d = 100 nm (Table 1): first, with a high carbon content (up to 70%) and low sulfur content (up to 0.5%); second, with a low carbon content (up to 57%) and high sulfur content (up to 11.5%). This is due to the presence of both hydrophilic sections w...

The effect of the chemical structure of the fiber-forming polymer of the reinforcing cloth on the properties of Polikon cation-exchange membranes prepared by polycondensation filling was analyzed. As a result, the sulfonated-phenol cation-exchanger matrix was synthesized and formed in the structure and on the surface of the cloth fibers at elevated temperatures.Extensive development of membrane technology in Russia and foreign countries has posed new problems for research at the crossroads of the physical chemistry of high-molecular-weight compounds, colloid chemistry, ion-exchange chemistry, and electrochemistry. The subjects of the present studies were synthetic polymeric membranes including ion exchangers. The application of these enables the more rational use of natural resources and the provision of ecologically pure food products and drinking water to the public.A promising method for preparing composite ion-exchange membranes is polycondensation filling. This results in the synthesis and formation of a polymeric ion-exchange matrix on the surface and in the structure of the fibers of reinforcing cloth or non-cloth material. Researchers at Engels Technology Institute paid special attention to the selection of effective materials for the reinforcement of membranes and a study of the effect of the processing parameters for preparing them on the structure and electron-transport properties that enabled materials with given properties to be subsequently prepared.A polymeric composite membrane contains within it from 10 to 30% (by mass) (depending on the brand) of fibrous filler that is added in order to reinforce mechanically the item. The most widely used reinforcing systems for industrial ion-exchange membranes are cloths and non-cloth materials of polyamide and thermoplastic polyester fibers. Studies carried out previously by Russian researchers showed that a reinforcing material in a membrane affected significantly both its physical-mechanical and electrochemical properties, structural characteristics, and mainly the formation of transport channels. For example, the maximum moisture content for MF-4SK membranes after reinforcement decreased by 33%. This reduced their transport characteristics. * Incorporation into a membrane of a non-conducting reinforcing cloth decreases significantly its electrical conductivity. Based on this, it can be concluded that the approach to preparing membranes where the reinforcing cloth is viewed exclusively from the viewpoint of mechanical strength and resistance to the medium for synthesizing the matrix and the aggressive media in which it is used without considering the possible contribution of structural, transport, physicochemical, and electrochemical properties requires thorough re-examination and rationalization.Reinforcing cloth satisfying the basic requirements imposed on membrane reinforcement systems and also having a positive effect on the membrane electrochemical properties was selected for preparing Polikon cation-exchange membranes. The main feature of the studied...

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