Chemical Journal of Kazakhstan

PRODUCTION OF PROPPANTS BASED ON FERROALLOY PRODUCTION WASTE AND ASSESSMENT OF THEIR OPERATIONAL CHARACTERISTICS

Kairat Adyrbekovich Kadirbekov — 2025-12-04

The possibility of producing proppants from ferroalloy production waste (RFKh and VUFKh slags) using liquid glass and a polymer coating (PVA) was investigated.

It was found that VUFKh slag, rich in strength-forming phases (90.5%), is the most promising raw material. Proppants obtained from VUFKh slag achieved standard sphericity values, but do not meet the requirements of GOST 54571-2011 for crush resistance (20% excess of the standard) and solubility in HCl.

The technological feasibility of producing magnesium silicate proppants, suitable for use in medium-pressure reservoirs, has been substantiated, with the need for further optimization of the mixture composition and firing regime to achieve full compliance with GOST. The use of this waste is recognized as economically viable.

DEVELOPMENT OF RUTHENIUM-FREE ORGANOELEMENTAL DYES FOR HIGH-EFFICIENCY DYE-SENSITIZED SOLAR CELLS UTILIZING AZERBAIJANI CLAY MINERAL-TIO₂ COMPOSITE PHOTOANODES

Nurlan Najafzade — 2025-12-04

Introduction: To overcome the drawbacks caused by the high price and limited availability of conventional Ru(II)-based sensitizer, such as N-3 and N719, and to achieve the commercial possibility for dye-sensitized solar cells (DSSCs), the development of new sensitizers is of great significance. In this paper, we explore an energy-efficient and high-performance new architecture. Goals and objectives: The overall goal is to develop an innovative DSSC architecture by synergistically combining high-efficiency, ruthenium-free, organoelemental dyes with nanostructured composite photoanodes. The aim is to establish a route to low-cost, high-performance photovoltaics by making use of readily available, abundant clay minerals in Azerbaijan as key photoanode constituent. Methods: The approach adopted involves preparation of new composite photoanodes based on titanium dioxide (TiO₂) mixed with locally sourced clay minerals (bentonite and kaolinite). The preparation methods of the clay-TiO₂ composites and their photoanode film fabrication are described. The chapter combines a critical overview of the main active classes of metal-free dyes—porphyrins, phthalocyanines, and indolines—to couple with these novel anodes. Results and Discussion: The combination of Azerbaijani clay minerals to the TiO₂ photoanode will bring in significant benefits to the device performance through different synergistic actions. These factors are (1) the higher specific surface area favoring an enhanced dye loading and light harvesting efficiency, (2) the incorporation of light-scattering centers resulting in a prolonged optical path length across the photoanode; and (3) significantly, the prevention of charge recombination at the photoanode/electrolyte interface by surface passivation. Based on physicochemical studies, it is argued that these effects will contribute to a marked enhancement in the crucial photovoltaic (J_sc/V_oc) parameters, resulting in an overall improvement in the PCE of the device. Conclusions: The combination of advanced organic dyes and novel clay-composite photoanodes proposed in this study is a very attractive practical method to develop cost-effective, environmentally friendly photovoltaic technology. The work has demonstrated a promising theoretical and practical approach for experimenting and optimizing a next-generation high-performance sustainable DSSC, with local natural resources to meet a global energy challenge.

N-BENZYLBISPIDINE WITH METHOXYPHENETHYL AND IMIDAZOLEPROPYL PHARMACOPHORES: ASSESSMENT OF MYELOSTIMULATING AND GROWTH-STIMULATING ACTIVITY OF NOVEL DERIVATIVES β-CD COMPLEXES

Altynay Kaldybayeva — 2025-12-04

Introduction. The search for new biologically active compounds remains one of the key goals in medicinal chemistry. The goal of the present study to synthesize two groups of compounds: derivatives of methoxyphenethylamine and imidazolpropylamine with a mandatory N-benzylbispidine backbone and evaluate their potential as plant growth regulators and myelostimulators. Results and Discussion: New series of 3,7-diazabicyclo[3.3.1]nonan-9-ones were synthesized using traditional methods. The structure of the obtained compounds was confirmed using nuclear magnetic resonance (NMR) spectroscopy, infrared spectroscopy, and elemental analysis. Conclusion. New bicyclic systems have been synthesized in order to identify compounds with high biological potential. The myelostimulating activity of the obtained compounds 5βCD, 6βCD was evaluated in laboratory white female rats and growth-stimulating activity in wheat and soy seeds. The results of the study of myelostimulating activity showed that an imidazole derivative, namely the complex 6βCD, at a dose of 5 mg/kg in a volume of 0.5 ml, exhibits moderate activity against leukocytopoiesis, erythrocytopoiesis and thrombocytopoiesis. The results of the study of growth-stimulating activity showed that the complex (5βCD, HZR-112) stimulates plant growth on soybean seed seedlings. However, the complex (6βCD, HZR-109) does not stimulate the growth of wheat and soybeans, but is an inhibitor. It turned out that the combination of the bispidin fragment with methoxyphenethyl or imidazolepropyl is very promising for the search for new biologically active substrates of various types of action.

ISOLATION OF RICE HUSK OIL AND PREPARATION OF FATTY ACID MONOGLYCERIDES

Nurbol Appazov — 2025-12-04

Rice husk, a widespread by-product of agro-industrial production, contains residual vegetable oils rich in unsaturated fatty acids. In this study, an eco-friendly and efficient strategy is presented for converting rice husk biomass into monoglycerides — compounds of significant industrial relevance. The process began with extraction of the raw material in a semi-automatic Soxhlet apparatus (ASV-6M) using ethyl acetate, which demonstrated the highest efficiency among six tested solvents, providing an oil yield of up to 2.82%. The obtained oil was subjected to catalytic glycerolysis under moderate pressure and temperature conditions (220 °C, 4 h) in the presence of potassium hydroxide, resulting in approximately 68.87% monoglyceride formation. Product purification was carried out by a two-step method: crystallization in an acetone–water system followed by column chromatography on silica gel, which enabled isolation of monoglycerides with a purity of up to 93%. Structural and compositional analyses were performed using gas chromatography–mass spectrometry (GC–MS) and infrared (IR) spectroscopy, which confirmed the presence of key esters — monoglycerides of palmitic and oleic acids. Mass spectrometry data confirmed molecular weights consistent with the structures of the monoglycerides, while the IR spectra revealed characteristic absorption bands corresponding to ester and hydroxyl functional groups.

BIOREMEDIATION OF HERBICIDE-CONTAMINATED SOILS

Elbey Rasim Babayev — 2025-12-04

Contamination of soils, groundwater, and surface water with herbicides poses significant cleanup challenges. Currently, the most common approach is containment, which involves expensive disposal of heavily contaminated soils to landfills. Bioremediation methods for in-situ treatment are needed as alternative and/or complementary approaches for cost-effective, waste-free cleanup. Microbes can be used to remediate herbicide-contaminated soil through a process called bioremediation, in which microorganisms degrade or convert contaminants into less harmful ones. This process can occur naturally or be enhanced by adding certain microorganisms or nutrients to the soil. Microorganisms such as bacteria and fungi have enzymes that can break down herbicides into less toxic compounds. They often use these herbicides as a food source. Remediation can be done in situ or by removing the soil for treatment (ex situ). Microbial remediation is influenced by the following factors: microbial activity (the type and number of microorganisms present and their ability to degrade a particular herbicide); environmental conditions (factors such as temperature, humidity, pH, and nutrient availability can affect the growth and activity of microorganisms); herbicide properties (the chemical structure and concentration of the herbicide can affect its biodegradability); soil properties (soil type, organic matter content, and aeration can affect microbial activity and the bioavailability of the herbicide).

CLINICAL EFFICACY OF DOSAGE FORMS IN PATIENTS WITH TUBERCULOSIS AND DIABETES: A COMPARATIVE REVIEW

Assem Uzakova — 2025-12-04

Abstract. Introduction. Tuberculosis (TB) and diabetes mellitus (DM) are increasingly recognized as a clinically and epidemiologically significant comorbidity that complicates treatment strategies and worsens clinical outcomes. DM increases the risk of developing active TB and negatively affects treatment response and prognosis. The purpose of this work is to provide a comparative analysis of the clinical efficacy and bioavailability of different antituberculosis dosage forms – tablets, syrups, and injections – used in patients with TB and DM comorbidity. Results and discussion. The literature review demonstrated that the pharmacokinetic properties of each dosage form and patient adherence significantly influence treatment effectiveness. Tablet forms are widely used and convenient, but their bioavailability may be reduced in patients with gastrointestinal complications associated with DM. Syrup formulations are suitable for patients with swallowing difficulties and for children, offering good bioavailability, though their storage stability is lower. Injectable forms provide a rapid therapeutic effect but are less practical for long-term treatment because of the need for medical supervision and potential discomfort. Recent international guidelines emphasize short, fully oral treatment regimens and patient-centered approaches. However, there remains a lack of targeted pharmacokinetic studies focusing on TB–DM populations. Conclusion. Different dosage forms used in TB treatment demonstrate distinct pharmacokinetic profiles and clinical effectiveness, which must be considered in the management of TB–DM comorbidity. Current international recommendations prioritize short oral regimens, but further research is needed to optimize drug formulations and improve treatment outcomes in this vulnerable patient population.

INTERPOLYMER SYSTEMS OF POLY(METHACRYLIC ACID): POLY(4-VINYLPYRIDINE) FOR THE SELECTIVE SORPTION AND DESORPTION OF RHENIUM IONS

Arman Baishibekov — 2025-12-04

Introduction. Rhenium is a rare transition metal used in alloys and catalysis. Industrial recovery comes mainly from sulfuric acid effluents formed during copper and molybdenum processing. Sorption is the main method, but the choice of effective sorbents remains an issue. Aims. Interpolymer systems (IPS) of poly(methacrylic acid) (PMAA) and poly(4-vinylpyridine) (P4VP) were prepared and tested. IPS samples with different PMAA:P4VP ratios were prepared and tested. Sorption capacity, desorption behavior, and structural as well as thermal characteristics were investigated. Results and Discussion. The sorption efficiency varies with polymer composition. The 2:4 PMAA:P4VP ratio gave the highest uptake. Desorption in 2% nitric acid was moderate, with a maximum of about 75.6%. FTIR spectra showed shifts in carboxyl and pyridyl bands, confirming the role of functional groups. TGA/DSC data indicated stabilization of the polymer network after rhenium binding. Conclusion. The PMAA:P4VP system at a 2:4 ratio combined high sorption, moderate desorption, and improved structural stability. This system may be applied for rhenium recovery from metallurgical wastewater.

SUSTAINABLE DYNAMIC POLYMER NETWORKS FOR PACKAGING: DEVELOPMENT AND PROSPECTS OF BIO-BASED VITRIMERS

Ainash Kairatovna Baidullayeva — 2025-12-04

Abstract. Introduction. The development of biodegradable and recyclable polymer materials is a key priority in the context of the global environmental crisis and the growing accumulation of plastic waste. In recent years, a new class of materials-vitrimers-have been attracting significant interest due to their unique combination of thermoset-like mechanical strength and reprocess ability enabled by dynamic covalent bonding. Objective of the study. This review article presents current approaches to the synthesis and application of bio-based vitrimers, primarily derived from epoxidized vegetable oils (EVO). Results and Discussion. Chemical strategies for creating polymer networks are studied in detail, including transesterification mechanisms, catalyst selection, and crosslink density control. The potential for structural modification using natural additives such as cellulose and lignin is discussed with the aim of enhancing mechanical, barrier, and antioxidant properties. Particular attention is given to the functional performance of these materials, including thermal resistance, moisture stability, mechanical robustness, self-healing capacity, and biodegradability. Recent research highlights the potential of bio-based vitrimers for practical implementation as packaging materials for various applications, including food, pharmaceutical, and active packaging systems with biofunctional barrier properties. Conclusions. Special emphasis is placed on the scalability of synthesis processes, durability under real-world conditions, and environmental safety.

DEVELOPMENT OF A METHOD FOR OBTAINING SODIUM ALUMINOSILICATE FROM RICE HUSK AND INVESTIGATION OF ITS SORPTION PROPERTIES

Nurbol Orynbasaruly Appazov — 2025-12-04

This study focuses on increasing the value of large-scale agricultural waste – rice husk – considered a silicon-rich renewable resource for the production of functional materials. Special attention is given to the synthesis of sodium aluminosilicate, which serves as an efficient sorbent for the purification of natural and industrial wastewater from heavy metal ions and organic pollutants. The proposed method begins with the preparation of sodium silicate by microwave treatment of a mixture containing 10 g of ground, washed, and air-dried rice husk and 130 mL of 1 M NaOH solution. The obtained sodium silicate solution is then mixed with 50 mL of saturated aluminum sulfate solution under continuous stirring. As a result, sodium aluminosilicate is formed and precipitates out of the solution. Filtration, washing, and thermal treatment of the precipitate at various temperatures yield sorbents with high specific surface area and a well-developed porous structure. This approach not only ensures the efficient utilization of difficult-to-recycle agricultural waste but is also environmentally friendly and resource-efficient. The synthesized aluminosilicates demonstrate excellent sorption capacity, making them promising for use in water treatment systems, industrial emission control, and the development of selective adsorbents.

STABILIZATION OF ASPHALTENE DEPOSITION USING NEW DEEP EUTECTIC SOLVENTS

Kanat Amirkulovich Sadykov — 2025-12-04

Introduction. Currently, one of the most common problems in the field of oil production, processing, and transportation is the aggregation and precipitation of asphaltenes. Asphaltene deposits clog pipelines, pumps, separators, and other technological equipment, significantly reducing the efficiency of oil extraction. This situation leads to technical disruptions, decreased product quality, additional financial costs, and increased environmental risks. The purpose of the work: is to apply deep eutectic solvents as inhibitors of asphaltene precipitation in oil for stabilization purposes. Results and discussions: A deep eutectic solvent was synthesized, asphaltenes were extracted from oil from the Karazhanbas oil field, and a model oil was prepared. The effectiveness of using new green inhibitors for asphaltene precipitation in model oil was studied using UV spectroscopy. Conclusion: The research results showed that the synthesized deep eutectic solvent based on betaine performed well as an inhibitor and can be applied in the oil industry for enhancing oil recovery stabilization.

DEVELOPMENT AND CHARACTERIZATION OF CHITOSAN AND 4-CHLOROBENZALDEHYDE-BASED SCHIFF BASES AND ASSESSMENT OF THE ANTIMICROBIAL PERFORMANCE OF DERIVED HYDROGELS

Danelya Nurlanovna Makhayeva — 2025-12-04

Introduction. Microbial resistance to antibiotics is a major global health challenge, as the growing number of multidrug-resistant pathogens limits treatment options and increases morbidity and mortality. This situation necessitates the development of eco-friendly and effective alternatives, including novel antibacterial agents. Schiff bases—organic compounds with an imine group (>C=N–)—are promising due to their simple synthesis, structural diversity, and broad biological activities, including antimicrobial effects. Of particular interest are Schiff bases derived from chitosan, a natural polymer known for its biocompatibility, non-toxicity, and high potential for chemical modification, which can improve its physicochemical and biological properties for applications in medicine and biotechnology. This study aimed to synthesise Schiff bases based on chitosan and 4-chlorobenzaldehyde and to evaluate their structural and functional properties. The compounds were characterised by IR and NMR spectroscopy, and their properties were studied using thermal analysis, rheological measurements, and assessment of adhesive behaviour. Results and Discussion. The formation of Schiff bases was confirmed by IR and NMR spectroscopy. Thermal analysis showed increased glass transition temperature and thermal stability of the samples. Hydrogels prepared from methylcellulose and modified chitosan exhibited thixotropic behaviour and significant antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans. Conclusion. Modified chitosan demonstrated improved properties and strong antimicrobial activity, indicating its potential as a basis for creating new antimicrobial materials for use in medicine, cosmetology, and the food industry.

REGIOSELECTIVE HYDROALKOXYCARBONYLATION OF 1.3-BUTADIENE, 1.5-HEXADIENE, AND 1.7-OCTADIENE USING PALLADIUM-PHOSPHINE CATALYTIC SYSTEMS

Abzal Meirembekuly Azimbay — 2025-12-04

Hydroalkoxycarbonylation of dienes offers a straightforward and atom-economic route to valuable esters derived from simple unsaturated feedstocks and carbon monoxide. In this work, we investigated the regioselective hydroalkoxycarbonylation of three representative substrates: 1.3-butadiene, 1.5-hexadiene, and 1.7-octadiene, using palladium-phosphine catalysts in ethanol at 120°C under 2.5 MPa CO. Two catalysts, [PdCl₂(PPh₃)₂] and [Pd(PPh₃)₄], were tested in combination with additional PPh₃ and p-toluenesulfonic acid. Across all three dienes, the reactions consistently favored formation of the linear ester, with yields increasing as the diene chain length grew and conjugation decreased: from 2.31% for ethyl 4-pentenoate (from 1,3-butadiene) up to 32.08% for ethyl 8-nonenoate (from 1,7-octadiene). The superior performance of Pd(PPh₃)₄ compared with PdCl₂(PPh₃)₂highlights the importance of electron-rich Pd(0) species in stabilizing acyl intermediates and sustaining catalytic turnover. These findings not only clarify how catalyst structure and substrate features influence reactivity in diene hydroalkoxycarbonylation but also provide practical guidance for tailoring conditions to enhance linear selectivity. Such insights expand the synthetic potential of this methodology for producing C₅-C₁₀ esters relevant to polymer, plasticizer, fragrance, and fine-chemical applications.

SYNTHESIS AND CHARACTERIZATION OF THERMORESPONSIVE COMPOSITE PATCHES BASED ON GELLAN GUM, CHITOSAN, AGAR, AND POLY(2-OXAZOLINE) DERIVATIVES

Gulzeinep Urisbayevna Begimova — 2025-12-04

Biodegradable polymer composites were developed using gellan gum, agar–agar, and chitosan as natural matrices, with poly(2-ethyl-2-oxazoline) (PEOZ, 0.15 g) added as a functional modifier. Four film types (GG–Ch, GG–Ch–Ox, A–Ch, A–Ch–Ox) were evaluated for structural and physicochemical performance. The films showed thicknesses of 0.1648–0.3455 mm and masses of 3.70–5.68 g. Incorporation of PEOZ significantly improved folding endurance, increasing it from 68 to 90 cycles in gellan–chitosan and from 42 to 76 cycles in agar–chitosan composites. Swelling and sol–gel analyses revealed higher crosslinking density and lower soluble fraction in modified samples. FTIR spectra confirmed hydrogen bonding and electrostatic interactions, while SEM-EDS of GG–Ch–Ox demonstrated a homogeneous surface with Na⁺/Cl⁻ distribution, indicating efficient ionic crosslinking. The modified systems exhibit improved mechanical stability, water retention, and morphological uniformity, making them promising candidates for biomedical uses such as wound dressings and transdermal patches.