PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY最新文献

{"title":"Synthesis and biological testing for pesticidal activity of 8-azasteroids","authors":"A. N. Pyrko","doi":"10.21285/2227-2925-2022-12-1-8-14","DOIUrl":"https://doi.org/10.21285/2227-2925-2022-12-1-8-14","url":null,"abstract":"The aim of the present study is the synthesis and testing for pesticidal activities of 2,3-dimethoxy16,16-dimethyl-D-homo-8-azagona-1,3,5(10),13-tetraene-12,17а-one and 2,3-dimethoxy-16,16-dimethyl-dhomo-8-azagona-1,3,5(10),13-tetraene-12-imino-17а-one hydrochloride which could become the basis the basis of plant protection products. The first compound was obtained by condensation of 6,7-dimethoxy-2,3- dihydroisoquinoline with 2-acetyl-5,5-dimethylcyclohexane-1,3-dione. The second substance was synthesized by interaction of the first with ammonium chloride. 2-Acetyl-5,5-dimethylcyclohexane-1,3-dione was prepared by heating dimedone with acetic acid in polyphosphoric acid. 6,7-Dimethoxy-2,3-dihydroisoquinoline was synthesized in two steps. Boiling 2-(3,5-dimethoxyphenyl)ethylamine in formic acid gave the corresponding amide, which was cyclized in the presence of phosphorus oxychloride. The structure of the obtained compounds is confirmed by the data of IR, 1H NMR, UV spectra and elemental analysis. In the IR absorption spectra of 2,3-dimethoxy-16,16-dimethyl-D-homo-8-azagona-1,3,5(10),13-tetraene-12,17a-dione and 2,3-dimethoxy-16,16-dimethyl-D-homo-8-azagona-1,3,5(10),13-tetraen-12-imino-17a-one hydrochloride, enaminodiketone bands are present (1535, 1580, 1615, 1625, 1670 cm-1 ) and enimine ketone (1595, 1650, 3260 cm-1 ) groups, respectively. Their UV absorption spectra recorded in ethanol contain two absorption bands (265.303 and 268.317 nm) corresponding to ππ* transitions of the same molecular fragments. The mass spectra of the two obtained tetracycles contain peaks of molecular ions. 1H NMR spectra correspond to the structures of all obtained compounds The synthesized compounds were tested for certain types of insecticide (against Toxoptera graminum, Musca domestica, Meloidogyne incognita, Heliothis virescens, Diabrotica undecimpunctata howardi, Caenorhabditis elegans), fungicidal (against Drechslera, Erysiphe, Puccinia, Peronospora) and herbicidal (against Amaranthus retroflexus, Brassica rapa, Abutilon theophrasti, Alopecurus myosuroides, Avena fatua, Echinochloa crus galli) activities. Both synthesized compounds showed herbicidal activity against Amaranthus retroflexus, Brassica rapa, Abutilon theophrasti and insecticidal activity against Toxoptera graminum. Hydrochloride 2,3-dimethoxy-16,16-dimethyl-D-homo-8-azagon-1,3,5(10),13- tetraene-12-imino-17a-one showed insecticidal activity against Musca domestica and fungicidal activity against Drechslera.","PeriodicalId":20601,"journal":{"name":"PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90079316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A technology for producing electrode materials for lithium-ion batteries from Kazakhstan spodumene raw materials","authors":"A. Zhanabayeva, G. Bishimbayeva, D. Zhumabayeva, A. Nalibayeva, Y. N. Abdikalykov","doi":"10.21285/2227-2925-2022-12-1-141-152","DOIUrl":"https://doi.org/10.21285/2227-2925-2022-12-1-141-152","url":null,"abstract":"This study aims to develop a technology for producing innovative electrode materials for modern lithium batteries. An efficient technology for post-purifying of technical lithium carbonate to reach the level of battery quality (99.95%) was developed. This technology involves causticiziation of technical lithium carbonate, ultrafiltration and ion-exchange sorption of a lithium hydroxide solution, followed by precipitation of lithium carbonate with ammonium carbonate. Cation-exchange resins of the brands Purolite S930Plus, Purolite S940 and Purolite S950 were studied for sorption purification of lithium-containing solutions from calcium and magnesium impurities. Purolite S940 and Purolite S950 can be recommended as the most effective cation exchangers. The kinetic parameters of calcium and magnesium sorption were determined using a Purolite S940 cation exchanger. The bicarbonation mode was set at room temperature and a pressure of 0.3 atm. The synthesized samples of lithium-iron-phosphate studied by the sol-gel method. The structures of the obtained electrode materials corresponding to the standard profile of lithium-iron-phosphate were investigated by X-ray diffraction. The synthesized electrode materials in the structure of lithium half- and button cells confirmed their good electrochemical properties, stable operation of batteries and a high intercalation reversibility of lithium ions in the samples within the potential range of 2.5–4.3 V. The main research results are innovative cathode and anode materials of a new generation for modern lithium-ion batteries with significantly increased capacity and stability of operation, obtained from lithium precursors – battery grade lithium carbonate based on domestic mineral and technogenic raw materials.","PeriodicalId":20601,"journal":{"name":"PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76210950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impurity-impurity interaction during the growth of UMG-Si-based mc-Si","authors":"R. V. Presnyakov, S. M. Peshcherova, A. G. Chueshova, V. Bychinskii, A. Nepomnyashchikh","doi":"10.21285/2227-2925-2022-12-1-15-29","DOIUrl":"https://doi.org/10.21285/2227-2925-2022-12-1-15-29","url":null,"abstract":"This article investigates the relationship between the chemical composition and electrophysical properties of p- and n-type multicrystalline silicon ingots based on metallurgical silicon with a purity of 99.99 at.%. In particular, the role of impurity-impurity interactions in the production of multisilicon by the Bridgman vertical method is evaluated in order to identify approaches to controlling this process effectively. The phase equilibrium calculations in the “silicon–all impurities” and “silicon-impurity-oxygen” systems were carried out based on the Gibbs energy minimization in the Selector software package. The study investigates the rank correlations of the concentrations of various impurities with each other, as well as with the specified electrical resistivity (SER) and the lifetime of nonequilibrium charge carriers (NCC) in the direction of crystal growth. Pair correlations of the element distribution profiles were considered based on the role of the main factor represented by the ratio of individual impurity solubilities in solid or liquid silicon (k0), as well as from the standpoint of direct interaction between two elements. It was found that the k0 value for two individual impurities in silicon does not automatically lead to the pair correlation of their distribution profiles in the ingot. A significant effect on the distribution profiles of impurities in multisilicon with k0→0 has the factor of binding some part of the impurity into such a form that this impurity can be incorporated easily into a growing crystal. Binding may be induced by the interaction of the impurity in the melt with the oxygen background, its segregation at the grain boundaries, and its capture by the crystallization front in the composition of the liquid inclusion. Significant correlations of impurity distribution profiles in the ingot were demonstrated by the pairs whose elements interact without the formation of chemical compounds in the 25–1413 °C temperature range. The conducted phase equilibrium calculations for the “silicon–all impurities” system revealed the possibility of forming the VB2, TiB2, ZrB2, and MgTiO4 solid phases in the melt.","PeriodicalId":20601,"journal":{"name":"PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90889097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermochemical liquefaction of wheat straw in sub- and supercritical tetralin","authors":"S. N. Evstaf‘ev, E. S. Fomina, N. P. Tiguntceva","doi":"10.21285/2227-2925-2022-12-1-160-166","DOIUrl":"https://doi.org/10.21285/2227-2925-2022-12-1-160-166","url":null,"abstract":"The present work investigates the thermochemical conversion of wheat straw biomass in a suband supercritical tetralin medium. The experiment was carried out in a batch reactor at 285, 330, 380, 420 and 460 °C for 10 minutes. The process of straw liquefaction in subcritical tetralin was characterised by relatively high efficiency. At 420 °C, the biomass conversion rate amounted to 98.2% a.d.m. The maximum yield of liquid products during liquefaction (81.6% a.d.m.) was obtained at 380 °C. The liquid products were fractionated by successive extraction with hexane, water and ethanol. According to GC-MS data, the liquefaction products soluble in hexane comprised a mixture of low-molecular weight degradation products of straw components and tetralin derivatives, including methyl esters of fatty acids, aromatic compounds, alkanes and minor alcohols and ketones. When the process temperature increased, the content of esters diminished, followed by an increment in the proportion of aromatic compounds up to 50% rel. No esters and phenolic compounds were present in the liquefaction products soluble in hexane obtained at 460 °C. Dehydrogenation, alkylation and isomerisation of tetralin with the formation of naphthalene, 1,4-dihydronaphthalene and alkyl derivatives of tetralin, naphthalene and indane occurred under the given conditions. The conducted comparative analysis of infrared spectra for straw and solid products of liquefaction suggested that, at temperatures of up to 330 °C, the process of polysaccharide fragmentation is more pronounced in the straw biomass, while, at higher temperatures, the process of lignin fragmentation prevails. As a result, the IR-spectrum of the solid product obtained at 380 °C revealed weakly pronounced absorption bands of alkylaromatic structural fragments. At the same time, only the absorption bands of mineral components in straw ash and adsorbed water were observed in the IR-spectrum of the solid product obtained at 420 °C.","PeriodicalId":20601,"journal":{"name":"PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73961043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis of a graft copolymer of polybutyl acrylate on fish collagen substratum using the RbTe1.5W0.5O6 complex oxide photocatalyst","authors":"L. Semenycheva, M. A. Uromicheva, V. Chasova, D. Fukina, A. Koryagin, N. Valetova, E. V. Suleimanov","doi":"10.21285/2227-2925-2022-12-1-97-108","DOIUrl":"https://doi.org/10.21285/2227-2925-2022-12-1-97-108","url":null,"abstract":"In order to obtain a graft copolymer of polybutyl acrylate (PBA) on the substratum of emulsified fish collagen, RbTe1.5W0.5O6 complex oxide was used as a photocatalyst under visible light irradiation (λ = 400–700 nm). The emulsion was prepared by mixing the monomer and the aqueous collagen solution in a ratio of 1:2. Next, the catalyst was introduced into the resulting mixture, followed by stirring and ultrasound treatment. Before the reaction, the emulsion was bubbled with argon for 15 min. The reaction was carried out in an argon flow with continuous stirring. The radiation source was a 30 W visible light LED lamp placed at a distance of no more than 10 cm from the reaction mixture. At the end of the reaction, the emulsified organic phase was extracted with toluene, followed by phase isolation. In order to isolate the catalyst, the aqueous part of the solution was centrifuged for 30 min. Subsequently, the powder was repeatedly washed in distilled water at a temperature of 50 °C. The washed catalyst was dried, and the surface of the oxide after emulsion polymerization was examined using a scanning electron microscope. For the PBA–collagen graft copolymer emulsion isolated from the aqueous phase, molecular weight characteristics confirming the formation of a graft copolymer were obtained. It was established that the nitrogen content of amino acid residues in the PBA–collagen graft copolymer is significantly lower than in collagen, which indicates the formation of a graft copolymer. An analysis of films and sponges of PBA–collagen graft copolymer samples by scanning electron microscopy (SEM) showed a new structural-relief organization compared to collagen. A SEM analysis of the RbTe1.5W0.5O6 powder surface after the synthesis of the PBA–collagen graft copolymer detected fragments of polymer macromolecules on its surface. This can be explained by the fact that the catalyst used not only is a source of hydroxyl radicals, but сan also participate in the formation of a polymer on the powder surface due to the abstraction of a hydrogen atom from hydroxyl groups on its surface under the action of a hydroxyl radical.","PeriodicalId":20601,"journal":{"name":"PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72911280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Self-aggregating properties of inulin in a dilute solution","authors":"A. Nasriddinov, A. Ashurov, S. Kholov, I. B. Ismoilov, S. Usmanova, Z. K. Mukhidinov","doi":"10.21285/2227-2925-2022-12-1-38-49","DOIUrl":"https://doi.org/10.21285/2227-2925-2022-12-1-38-49","url":null,"abstract":"The creation of functional food products based on inulin-containing vegetable raw materials can provide the population with functional diabetic nutrition. In this regard, investigation of the technological parameters of obtaining inulin from Jerusalem artichoke tubers (Helianthus tuberosus L.) and determination of its quantitative characteristics seem highly relevant. This study aims to determine the qualitative characteristics of inulin obtained from Jerusalem artichoke tubers by both flash extraction and conventional methods. Jerusalem artichoke inulin samples were obtained by the flash extraction method at a high temperature of 105 °C during both shorter and longer periods of time and by the conventional method at a temperature of 75 °C in a neutral medium. The hydrodynamic properties and molecular weight of the samples demonstrated the self-aggregating properties of this biopolymer. Inulin obtained by the flash extraction method consists of two fractions: low-molecular weight inulin and high-molecular weight aggregate represented by a polysaccharide complex. These aggregates can be formed both by inter- and intramolecular interactions of various inulin fractions in the solution. As expected, their isolation using conventional methods appeared impossible: the method of concentration yielded a number of subfractions on the UV membrane and a large amount of aggregated water-insoluble microgel. At the same time, inulin obtained by the conventional method consists of one fraction, although having a high degree of polydispersity. In order to obtain high-quality inulin intended for nutritional and prophylactic purposes, it is preferable to use the flash extraction method over short periods of time.","PeriodicalId":20601,"journal":{"name":"PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75942185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Energy profile of formal 1,2-dyotropic rearrangement of diarylethenes","authors":"E. K. Kouame, A. G. Lvov","doi":"10.21285/2227-2925-2022-12-1-153-159","DOIUrl":"https://doi.org/10.21285/2227-2925-2022-12-1-153-159","url":null,"abstract":"Diarylethenes with thiophene substituents belong to photoswitchable compounds (photoswitches or photochromes). Upon UV irradiation, their colorless open-ring isomers (DAE-o) convert to the colored closed-ring isomers (DAE-c), while the back reaction is induced only by visible light irradiation. A multiple photoswitching of diarylethenes usually results in irreversible photorearrangement of DAE-c to the so-called annulated isomers DAE-a, that are stable thermally and photochemically. In the present communication, structures of a series of diarylethenes as well as their isomers were optimized on the B3LYP/6-31G(d) level of theory. It was disclosed for the first time, that DAE-a destabilized relatively DAE-c by 1.71–14.00 kcal/mol. These results are important for design of photocontrollable molecules and materials, operated in the oneway (permanent manner).","PeriodicalId":20601,"journal":{"name":"PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90652577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Feasibility study of using biodiesel fuels as a blendstock of commercial diesel fuels","authors":"N. Belozertseva, O. M. Torchakova, I. Bogdanov, M. Kirgina","doi":"10.21285/2227-2925-2022-12-1-130-140","DOIUrl":"https://doi.org/10.21285/2227-2925-2022-12-1-130-140","url":null,"abstract":"Reducing emissions associated with the combustion of hydrocarbon fuels and increasing the consumption of biofuels represents an urgent economic and environmental task. Biodiesel is an alternative to petroleum diesel fuel and is widely used as a commercial fuel blendstock. In this regard, it is important to study the feasibility of using biodiesel obtained from various raw materials as a blendstock of commercial diesel fuels, as well as to identify optimal ratios of biodiesel fuel/petroleum diesel fuel. The addition of even small amounts of biodiesel has a positive effect on the environmental properties of the fuel. In the present study, we synthesize biodiesel fuel from sunflower, corn, and rapeseed oils by the reaction of interesterification using ethyl alcohol as an interesterifying agent and sodium hydroxide as a catalyst. The composition and properties of the synthesized biodiesel fuels were determined. Blends of biodiesel/petroleum diesel fuel with 5, 10, 15, 20 vol.% biodiesel blend content were prepared followed by determination of their composition and properties. It was found that the addition of biodiesel fuel increases the density, viscosity, and self-ignition of the resulting fuel, at the same time as decreasing the sulfur content and making the fractional composition heavier. This effect is directly proportional to the concentration of biodiesel in the blend. The effect of reducing the limiting filterability temperature of the blend fuel by the addition of biodiesel was revealed, with its maximum achieved at different concentrations of biodiesel synthesized from sunflower, corn, and rapeseed oils. For the production of a summer commercial diesel fuel, we recommend blends of 10vol.% biodiesel fuel, derived from any of the vegetable oils under study, and 90vol.% petroleum diesel fuel.","PeriodicalId":20601,"journal":{"name":"PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82571813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the proteolytic activity of new cryoresistant lactobacillus strains","authors":"S. Kitaevskaya, V. Ponomarev, O. Reshetnik","doi":"10.21285/2227-2925-2022-12-1-76-86","DOIUrl":"https://doi.org/10.21285/2227-2925-2022-12-1-76-86","url":null,"abstract":"The search for new functionally active strains of lactic acid bacteria, together with the development of domestic competitive starter cultures on their basis, are important directions of contemporary food biotechnology. Proteolytic activity represents one of the criteria for selecting lactic acid bacteria strains for their subsequent use in food production and largely determines the quality characteristics of the finished product. The present study aims to evaluate the proteolytic activity of 15 new cryoresistant strains of Lactobacillus genus lactic acid bacteria having a number of functional and technological properties. According to the results obtained, all strains demonstrated higher proteolytic activity in alkaline media and those close to neutral (pH = 6.5). In slightly acidic media, the strains under study showed minimal values of proteolytic activity, except for L. fermentum 12 and L. plantarum 21 strains. Strains L. casei 32, L. casei 36, L. fermentum 10, and L. acidophilum 9 (48.9–52.3 µg tyrosine/mL·min) showed the maximum proteolytic activity. The minimal proteolytic activity was characteristic of L. fermentum 12, L. fermentum 24, and L. plantarum 1 (27.7–28.9 µg tyrosine/mL·min). The studied paramenter depends on the conditions of proteolysis (substrate, medium pH) and represents an individual strain characteristic independent of the lactobacillus species membership. According to the results obtained, L. casei 32, L. casei 36, and L. fermentum 10 cryoresistant strains, manifesting high proteolytic activity and effectively affecting various protein substrates (casein, albumin, haemoglobin) in a wide range of medium pH values, can be recommended for inclusion in the composition of starter cultures for the production of fermented food products.","PeriodicalId":20601,"journal":{"name":"PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84801960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sorption of silver (I) ions from aqueous solutions using the synthetic sorbent","authors":"N. Afandiyeva, A. Maharramov, F. M. Chyragov","doi":"10.21285/2227-2925-2022-12-1-30-37","DOIUrl":"https://doi.org/10.21285/2227-2925-2022-12-1-30-37","url":null,"abstract":"We study the sorption of silver ions from aqueous solutions by a synthetic chelating sorbent. In the presence of formaldehyde, a polymeric sorbent based on a copolymer of styrene with maleic anhydride, modified with N,N’-diphenylguanidine, was synthesized and further used for extracting Ag(I) ions. The composition and structure of the synthesized polymeric chelating sorbent were studied using IR and UV spectroscopy methods. A simple, inexpensive, and efficient method for extracting Ag(I) ions from aqueous solutions was used. The effect of various parameters on the sorption process was studied, including the acidity of the medium (pH), the initial concentration of the metal ion, the time required to establish complete sorption equilibrium, and ionic strength. The optimum pH value for the extraction of Ag(I) was found to be 6. The process is characterized by a high adsorption capacity reaching 547.2 mg/g. The research results showed that the time required to establish a complete sorption equilibrium for the sorbent modified with N,N’- diphenylguanidine is 60 min. Ag(I) adsorption increases up to the value of ionic strength of μ = 1, after which its intensity decreases. At the final stage, the process of desorption of absorbed silver ions was carried out. During desorption, the best eluting agent for the extraction of Ag(I) was determined to be 0.5 M HNO3. The sorbent can be re-used after regeneration. The copolymer of styrene and maleic anhydride modified with N,N’-diphenylguanidine has a high sorption capacity and, therefore, can be used as a potential adsorbent for the extraction of silver (I) from aqueous solutions.","PeriodicalId":20601,"journal":{"name":"PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81541439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}