Russian Journal of Applied Chemistry最新文献

Dibutoxyethyl and diphenoxyethyl esters of dicarboxylic acids were synthesized with a yield of more than 85%. Using the Hansen method and the critical dissolution temperature, it was established that phenoxy derivatives possess better thermodynamic compatibility with PVC; however, the kinetic factor shows an inverse relationship. DMA analysis demonstrated the homogeneity of all compositions, while butoxy derivatives more effectively reduce the glass transition temperature (down to –37.1°C) and expand the high-elasticity range. The substitution factor for butoxy esters (0.84–0.91) confirms their higher efficiency compared to DOP, whereas phenoxy esters are inferior. The ester structure is the key factor determining the plasticizing properties.

The hydrogenolysis of glycerol was investigated in a fixed-bed catalyst reactor over bifunctional catalysts containing 15 wt % copper supported on SAPO-11, Al-HMS (20), BEA-38, and Al-SBA-15(20); the industrial copper chromite catalyst CuCr₂O₄ was used as a reference sample. The physicochemical properties of the catalysts (acidity, textural characteristics, and metallic copper dispersion) as well as their catalytic performance in the temperature range of 180–260°C at pressures up to 6 MPa were compared. It was shown that the distribution of hydrogenolysis products depends on the type of aluminosilicate used and the ratio of acid to metal sites. The 15% Cu/SAPO-11 catalyst in the range of 220–240°C provided preferential formation of 1,2-propanediol, whereas systems with a larger number of acid sites (15% Cu/BEA-38 and 15% Cu/Al-HMS (20)) at elevated temperature promoted sequential hydrogenolysis to propyl alcohols. An increase in pressure above 4 MPa and in the hydrogen/feed ratio above 500–1000 Nm³/m³ did not lead to a substantial improvement in the performance. Differential IR spectroscopy data for the surface of the spent catalysts indicated the absence of carbonaceous deposits. Organic compounds present on the surface were represented by aliphatic and aromatic oxygenates (predominantly ethers and acetals); their presence were not the cause of catalyst deactivation, which was instead due to agglomeration of copper particles.

An efficient and environmentally friendly method was developed for the synthesis of novel 1,8-naphthyridine derivatives through a one-pot multicomponent reaction under ultrasonic irradiation. The reaction of quinoline-2-amine, malononitrile, and various substituted aldehydes was carried out in water using morpholine as a catalyst, affording the desired 1,8-naphthyridine-3-carbonitrile derivatives in high yields within a short reaction time. The ultrasound-assisted protocol significantly improved reaction efficiency compared with conventional methods by reducing reaction time and increasing product yield under mild conditions. The synthesized compounds were characterized by FT-IR, ¹H NMR, ¹³C NMR, and mass spectrometry, confirming their molecular structures. The antioxidant potential of the synthesized derivatives was evaluated using the DPPH free radical scavenging assay. Among the series, compounds 4g and 4j exhibited the most promising antioxidant activity with lower IC₅₀ values, indicating strong radical-scavenging ability. Furthermore, in-silico ADME and drug-likeness analyses using the SwissADME platform revealed that most compounds possess favorable physicochemical properties, good gastrointestinal absorption, and compliance with drug-likeness rules. Overall, this study presents a rapid and green synthetic strategy for generating biologically relevant 1,8-naphthyridine derivatives with promising antioxidant properties. The developed methodology supports Sustainable Development Goals (SDG 3: Good Health and Well-being and SDG 12: Responsible Consumption and Production) by promoting environmentally responsible chemical synthesis and potential therapeutic discovery.

In this work the response surface methodology has been used firstly for the specific surface area comprehensive investigation of the sulfated ZrO₂∙nH₂O materials synthesized by microwave heating. The following treatment conditions are varied: the promoter content according to the sulfur (1, 4.5, and 8 wt %), the heating temperature (250, 285 and 320°C) and the holding time (0, 5, and 10 min). There are two optimum areas: at the promoter content is 1 and 8 wt % according to sulfur, the low treatment temperature (250°C) and no additional holding time in the microwave oven (only heating to the set temperature). The catalytic systems prepared with a high specific surface area and strong acidic sites could be efficient used in catalytic processes.

The wastewater generated by pharmaceutical industries contains substantial amounts of antibiotics, which poses a significant environmental challenge. Therefore, it is essential to remove these contaminants from water effectively. In this study, a novel hydrogel-based adsorbent nanocomposite was introduced for removing antibiotics. Firstly a simple and environmentally friendly method for preparing Fe₃O₄@β-CD nanoparticles using an aqueous extract of Marrubium vulgare leaves was performed. Then, these nanoparticles were incorporated into hydrogels composed of chitosan and acrylic acid, resulting in the formation of a chitosan/acrylic acid/Fe₃O₄@β-CD nanocomposite hydrogel. The structure of the synthesized Fe₃O₄ NPs and nanocomposite hydrogel has been characterized using FE-SEM, EDS, XRD, BET, VSM, and FTIR spectroscopy. In the following, the effectiveness of this nanocomposite as a novel magnetic nano-biosorbent was evaluated. The FESEM image of the nanocomposite hydrogel’s morphology revealed a porous structure with pore sizes of approximately 20 µm, and Fe₃O₄@β-CD particles, averaging 35 nm in size, are uniformly dispersed within it. Further, the specific surface area value of synthetic nanocomposite hydrogel is 89.5 m² g^–1. Also, the results indicated that this nanocomposite achieved a tetracycline removal efficiency of over 80% after 120 min and demonstrated an antibacterial ability of more than 80% against some bacterial strains.

Carbon dots (C-dots) are promising nanomaterials with unique optical properties, including high photoluminescence, stability, and low toxicity compared to traditional luminophores. They can be used as luminophores in light-emitting diodes or as active layers in electroluminescent devices and have a long service life. However, their practical application is limited by their tendency to aggregate and concentration quenching in aqueous media. In this work, a method is proposed for stabilizing C-dots by incorporating them into polymer matrices—polyvinylpyrrolidone (PVP) and polyvinyl alcohol (PVA), which makes it possible to obtain transparent, mechanically strong, and highly efficient luminescent composite materials. C-dots were synthesized by the hydrothermal method from o-phenylenediamine, which ensured a high quantum yield (25%) and luminescence in the blue region of the visible spectrum. It was established that the optimal concentration of C-dots in water is 0.02 wt %, but their introduction into polymer matrices made it possible to significantly increase the content of nanoparticles without loss of luminescent properties. The highest luminescence intensity was observed at a concentration of 1.6 wt % C-dots in both polymer matrices. Using fluorescence microscopy, the uniform distribution of carbon dots in the polymers was confirmed, and on the basis of spectrophotometric analysis it was shown that the composite films possess high transparency throughout the entire visible range. At the same time, the films demonstrated good photostability: after 6 h of UV irradiation, the decrease in intensity was 27% for PVA-based composites and 30% for PVP-based ones. The obtained results demonstrate that the resulting polymer composite materials based on C-dots possess promising characteristics for application as light-converting coatings and components of various optoelectronic devices for display and information transmission, including light-emitting diodes, organic displays, light converters, and others.

Dye-sensitized solar cells (DSSCs) have garnered significant attention as a cost-effective and environment friendly alternative to traditional silicon-based photovoltaic systems. This study explores the use of carbon aerogel as a counter electrode material to improve DSSC performance. Carbon aerogels derived from waste newspaper have remarkable characteristics such as high porosity, large surface area, and excellent electrical conductivity, making them a viable and effective alternative to platinum. The use of a natural cocktail dye derived from mulberry, moss, and Cassia fistula flowers broadens the light absorption spectrum, while a polymer electrolyte composed of CMC and MWCNT provides stability and increased ionic transport. The carbon aerogel-based DSSC obtained a power conversion efficiency (PCE) of 4.52%, which was higher than the 3.85% PCE of platinum-based equivalents, attributed to enhanced catalytic activity, lower charge-transfer resistance, and enhanced sunlight harvesting. These findings highlight the potential of carbon aerogels and natural dyes to enhance the scalability and sustainability of DSSC technology.

The compound Li_1+xGe_xLa_2–xTiO₁₂ was prepared using a conventional solid-state reaction method, where Germanium (Ge) was substituted at the lithium site with varying Ge content (x) from 0.05 to 0.15. X-ray diffraction (XRD) analysis confirmed the formation of the conductive cubic phase. Scanning electron microscopy (SEM) was used to examine the surface morphology. The lattice parameters of the synthesized sample were also calculated. The sample with 0.10 Ge showed the highest ionic conductivity at room temperature. The maximum conductivity recorded was 9.24 × 10^–2 S/cm at an operating temperature of 350°C. This one-order magnitudes increase in ionic conductivity at room temperature makes the 0.10 Ge ceramic samples a promising candidate for solid electrolytes. Different amounts of GeO₂ were used to synthesize Ge-doped LiLaTiO (Ge-LLTO) perovskites via solid-state reactions, aimed at producing Li-ion conductive electrolytes for all-solid-state rechargeable lithium batteries. These samples were tested at various temperatures to optimize their ionic conductivity, especially at lower temperatures. The addition of GeO₂ has improved both the sinterability and Li ion conductivity of the perovskite solid electrolyte. Also, the vibrational and morphological studies provide an impact on the effective yield obtained through this research. The grain-boundary resistance decreased from 312 Ω at 150°C to 105 Ω at 350°C, indicating improved Li⁺ ion transport with increasing temperature. Arrhenius analysis yielded an activation energy of −0.31 eV, confirming thermally activated lithium-ion conduction and enhanced ionic conductivity in the Ge-substituted LLTO (x = 0.10) electrolyte. This study determined the optimal sample for sintering at 1250°C by evaluating the electrolyte’s microstructure and electrochemical properties, along with a study of germanium doping.

This paper presents a comprehensive experimental and techno-economic evaluation of used engine oil ultrafiltration using ceramic and polymeric tubular membranes. Both laboratory and pilot-scale studies were conducted using KUFE ceramic tubular membranes (Ceramic Filter LLC) and F1 polymeric tubular membranes (Vladipor R&D Center). The optimal temperature and pressure were identified as 383 K (110°C) and 0.4 MPa respectively for ceramics membrane, and 343 K (70°C) and 0.4 MPa respectively for polymeric membrane. An industrial plant layout was proposed with membrane unit staging and pump selection to maintain turbulent flow, and minimize fouling. Ceramic membranes exhibited higher specific productivity (0.014 m³ m⁻² h⁻¹) compared to polymeric membranes (0.006 m³ m^–2 h⁻¹). Despite their lower flux, polymeric membrane systems proved 20% more cost-effective at maximum throughput due to significantly lower capital and operating expenditures. The cost for ultrafiltration treatment of used engine oil ranges from 20000 to 25000 RUB/m³ (250–312 USD/m³), which is economically attractive comparing to the cost of fresh Group II base oil (70000 RUB/m³, or 850 USD/m³).

Ethephon an organophosphorus compound is widely used as a plant growth regulator in agriculture for early ripening of fruits and vegetables. The excessive use of artificial ripeners has raised serious concerns, as residual chemicals left on fruits enter the environment through household wastewater and runoff from agricultural fields. In this work, an effective and selective mixed micellar cloud point extraction has been developed for the extraction and preconcentration of ethephon residues from contaminated water using surfactants Triton X-114 (TX-114) and cetyl trimethyl ammonium bromide (CTAB). The influence of analytical parameters like pH, surfactant concentration (CTAB and TX-114), concentration of salting out agent (Na₂SO₄) equilibrium time and temperature were studied. Linearity was obeyed in the range of 0.164-3.294 ng mL^–1. The developed method was successfully applied to water samples collected from tomato cultivation fields near Tuni, Andhra Pradesh.