Physico-chemical properties and research of acids contained in oils of Uzbekistan

A method for the selective, simple and accelerated extraction-photometric determination of silver has been developed, based on the selective extraction of silver(I) from a strongly acidic medium in the presence of iodide ions and dimethylformamide and its complexation with dinaphthizone directly in the organic phase.The apparent molar extinction coefficient of the dinaphthizone complex of silver (I) at a maximum light absorption of 505 nm is 4.75·104. The calibration graph is linear in the range of 0.5-50 μg of silver (I) in 10 ml of extract. The determination of silver is not interfered with by large amounts of foreign ions in quantities up to 100,000 times within 2-5%. The extraction-photometric method developed for the determination of silver is recommended for analyzing silver content in diverse materials, including ores, rocks, industrial wastes, and other substances characterized by complex chemical compositions. Notably, this method is particularly advantageous as it eliminates the need for separating accompanying elements, streamlining the analytical process. By employing this extraction-photometric technique, analysts can achieve accurate and reliable results in the determination of silver content even in samples with intricate chemical matrices. This method enhances efficiency and expedites the analysis of materials that may contain a variety of elements besides silver.

Section: Methodsmentioning

confidence: 99%

Selective extraction of silver(I) and photometric determination di-(2-naphthyl)-thiocarbazone (dinaftizone) in the organic phase

Abdullaeva,

Giyasov,

Muratkulov

et al. 2024

“…In the second and subsequent saturation cycles, before the appearance of ions of the working solution in the filtrate (determined after the first cycle), the filtrate was collected in 100 and 250 cm 3 , respectively, the concentrations of the working solution. After the ions of the working solution appeared in the proportion of the filtrate, the total volume of the filtrate was calculated [16][17][18][19][20]. To determine the full dynamic exchange capacity, the solution was continued to flow until the concentration of the filtrate became equal to the concentration of the working solution.…”

Section: Methodsmentioning

confidence: 99%

Research new type of cation-exchange resin for waste water treatment

Pulatov,

Nazirova,

Sharipova

et al. 2024

This article presents the studies obtaining and research new polycondensation type phosphoric cation-exchange resin. The conditions for the phosphorylation of this polymer were selected from the experiments accumulated in relation to the phosphorylation reactions of low- and high-molecular compounds. The resulting polymer had an exchange capacity for a 0.1 N NaOH solution – 5,5-5,6 mEq/g and contained 16,5% phosphorus. Based on the studies carried out, the optimal conditions for the synthesis of the styrene-furfural polymer are assumed to be: the reaction temperature is 90°C, the concentration of the ZnCl2 catalyst is 0.07 mol per mole of furfural, and the molar ratio of styrene to furfural is 1:1. There was studied an interaction of the cation exchanger in Na- and H-forms with solutions of salts of copper sulfate, nickel, cobalt, sodium chloride, calcium and uranyl nitrate. In order to elucidate the mechanism of sorption of the cations of these metals, were taken the IR-spectra of the cation exchanger in the H- and Na- form, saturated with copper ions. The less dissociated phosphoric acid groups, the stronger hydrogen bond forms phosphoryl oxygen with OH-groups. Therefore, it can be expected that as the cation exchanger is saturated with sodium, the maximum of the band corresponding to the phosphorus-oxygen bond vibrations will slightly shift to longer wavelengths as a result of the destruction of the weaker hydrogen bond.

“…Since 1995, the production of these products has increased several times. However, 10% of the demand for pulp and paper products in Uzbekistan is satisfied [1][2][3]. Increasing the production of pulp and paper products is one of the most pressing problems of our time.…”

Section: Introductionmentioning

confidence: 99%

Composite papers based on natural polymers

Egamberdiev,

Khaydullaev,

Abdurazakova

et al. 2024

In this study, cellulose was extracted from Heliánthus tuberósus (Jerusalem artichoke) stems, and its quality indicators were thoroughly investigated. The isolation process involved the removal of impurities and non-cellulosic components, resulting in a purified cellulose sample suitable for further analysis and application.To explore the potential of Heliánthus tuberósus cellulose, composite paper was produced by incorporating basalt fiber into the cellulose matrix. The resulting paper was subjected to comprehensive testing to evaluate its mechanical properties, with a particular focus on tensile strength and tensile length.The tensile strength of the composite paper was determined using standardized testing methods, providing quantitative data on the material's ability to withstand applied forces without breaking or deforming. Tensile length, on the other hand, refers to the maximum elongation the paper can undergo before rupture occurs. These properties were assessed to gauge the overall performance and suitability of the composite paper for various applications.The obtained results were presented in a clear and concise manner, utilizing tables and graphs to facilitate data interpretation and comparison. Tables allowed for the tabulation of the measured tensile strength and tensile length values, providing a comprehensive overview of the material's mechanical characteristics. Graphs were employed to visualize trends, patterns, and potential correlations between different variables, aiding in a deeper understanding of the composite paper's behavior under various loading conditions.