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Горение и Плазмохимия
ISSN
1683-3902
3078-4778
3 результаты
Показано: 1 - 3 из 3
- Некоторые метрики заблокированы вашиминастройками согласия
Тип записи:Публикация, Structural and Sorption Characteristics of Nano-Structured Polysaccharide Biopolymers Derived from Plants of the Asteraceae Family(2026-07-17); ; ; ; This study investigates the structural and sorption characteristics of nanostructured polysaccharide biopolymers isolated from plants of the Asteraceae family (Dahlia tubers and Helianthus tuberosus) toward Pb2+ ions in model aqueous solutions. The biopolymers were obtained by acid extraction at pH 1.5-2.5 and 80-90 °C, followed by ethanol precipitation, with a yield of 10-14%.Surface morphology examined by scanning electron microscopy revealed a hierarchically organized nano- and micro structured matrix with particle agglomeration and developed interaggregate porosity. The presence of lamellar structures and a porous network promotes diffusion of metal ions to active functional centers.The interaction mechanism between the biopolymer matrix and Pb2+ was studied by FTIR spectroscopy. Shifts and intensity changes of absorption bands corresponding to carboxyl and hydroxyl groups confirmed a coordination-chelate complexation mechanism without destruction of the polysaccharide backbone.Sorption experiments were performed using model Pb2+ solutions prepared from analytical-grade lead (II) acetate. The residual Pb2+ concentration after contact with the biopolymer was determined by atomic absorption spectrometry at 283.3 nm using calibration. Additional control measurements were conducted by complexometric titration in acetate buffer medium (pH 5.5) with 0.01 M Trilon B.Up to 76-77% of Pb2+ was removed within the first 10 min, and sorption equilibrium was reached after 60 min. The maximum removal efficiency reached 87%. The Freundlich model best described the process, indicating heterogeneous surface structure and multilayer adsorption. These results demonstrate the potential of Asteraceae-derived polysaccharide biopolymers as environmentally safe sorbents for heavy metal removal from aqueous media. - Некоторые метрики заблокированы вашиминастройками согласия
Тип записи:Публикация, Combined-Method Synthesis of CaTiO3 and SrTiO3 Perovskites with n-Hexane: Impact on Structure and Microstructure(2026-07-17); ; ; ; K. RamachandranThis study reports the synthesis of CaTiO3 and SrTiO3 with a perovskite structure by a combined route involving preliminary wet mixing of CaCO3/SrCO3 carbonates and TiO2 in n-hexane, followed by a solid – state reaction during high-temperature calcination. The phase composition and crystal structure of the obtained materials were examined by X-ray diffraction with Rietveld refinement, while the microstructure and elemental distribution were studied using SEM\EDX, and local structure and surface groups were probed by ATR– FTIR spectroscopy. It is shown that the presence of the organic solvent and the applied thermal treatment lead to the formation of single-phase CaTiO3 and SrTiO3 with orthorhombic and cubic modifications, respectively, and with crystallographic parameters with reference PDF cards. The average crystallite size calculated using the Sherrer equation confirmed the nanocrystalline nature of the powders, whereas SEM/EDX analysis reveals a highly porous microstructure and a homogeneous elemental distribution without noticeable metallic impurities. It is established that A-site cation substitution Ca2+/Sr2+ in combination with n-hexane wet mixing induces systematic changes in lattice symmetry, IR band positions and agglomerate morphology, enabling targeted tuning of the texture and potential functional properties of perovskite titanates. The proposed combined approach is a technologically simple and scalable method for producing nanostructured oxide perovskites that are promising as supports and active phases in catalytic systems for combustion processes, plasma-chemical oxidation and functional ceramics. - Некоторые метрики заблокированы вашиминастройками согласия
Тип записи:Публикация, Synthesis and structure of polycrystals MnCo2O4-GdCrO4The article discusses the synthesis and structure of polycrystalline nanocomposite MnCo2O4-GdCrO4 material. The sol-gel method was used as a synthesis of the study. Using X-ray phase analysis (XPA), the structure of the synthesized nanomaterial composition was determined: spinel – cobalt manganate and perovskite – gadolinium chromite. Based on the results of the analysis, it was established that the polycrystalline two-phase composite is a system of spinel-cubic and perovskite-tetragonal types. Morphological analysis of the nanocomposite was carried out using a scanning electron microscope (SEM). According to the data obtained as a result of SEM, the elemental composition was confirmed and the average nanosize of the nanomaterial was obtained, and the content of the compound increased to x2000 was determined, the particle size of MnCo2O4 is 383-281 nm, GdCrO4 – 1.63-1.34 µm; increased to x4000, particle size – MnCo2O4 277-219 nm, GdCrO4 – 1.48-1.27 µm; increased to x6000, particle size – MnCo2O4 239-209 nm, GdCrO4 –1.21-1.07 µm.