Magnesium oxide (MgO) nanopowders were synthesized by an ultrasonic-assisted solution combustion synthesis route using magnesium nitrate as oxidizer and sucrose as fuel. The influence of ultrasonic pretreatment and fuel-to-oxidizer ratio on the phase composition, microstructure, surface area, particle size distribution, and dispersibility of the resulting MgO powders was systematically investigated. X-ray diffraction analysis confirmed the formation of single-phase cubic MgO for all samples. Compared to conventional solution combustion synthesis, ultrasonic pretreatment led to a pronounced reduction in crystallite size and particle agglomeration, accompanied by a significant increase in specific surface area. Under optimized conditions, MgO nanopowders with a high specific surface area of approximately 340 m2 g–1 and a narrow particle size distribution were obtained. The improved microstructural characteristics were attributed to cavitation-induced modification of precursor chemistry and more homogeneous combustion reactions. In addition, the functional properties of the synthesized MgO nanopowders were evaluated through antibacterial activity tests, demonstrating their potential applicability in advanced inorganic and functional materials.
Combustion wave dynamics were analyzed in a two-layer Ti–C–Cu system under SHS conditions. Utilizing equimolar Ti–C mixture with varying Cu amounts, the study showed that combustion temperatures surpassing the Cu liquidus drive interfacial metal migration and metallurgical welding. Variation in Cu content allowed for controlling the burning velocity, revealing that the refraction of the combustion wave front at the layer interface adheres to a relationship analogous to Snell’s law.
Solution combustion synthesis (SCS) to make few-layer graphene (FLG) from sucrose was demonstrated. Such a mass-producible and low-cost method is competitive as a candidate for industrial production of graphene. We used sucrose as a carbon source and ammonium nitrate as an oxidizing agent. The synthesized sample had a three-dimensional network and a porous structure with various kinds of sheets and sponge shapes, but after ultrasonication, it included lots of FLG. It was confirmed that the obtained production is highly defective and contains a large number of FLGs which don’t have enough bonding between them and can be easily separated. SEM, SPM, XRD, Raman, and BET analyses were carried out to confirm the characteristics of graphene, which prove 5–8 layers of graphene. The mechanical properties of nitrile butadiene rubber–graphene (NBR@FLG) composites were investigated by adding the synthesized FLG to NBR. It was confirmed that the addition of 0.5 phr of FLG to NBR increases tensile strength by 2.49 times, elongation by 2.28 times, and hardness by 1.66 times.
TiC-reinforced entropy-stabilized composites were synthesized via self-propagating high-temperature synthesis (SHS) in the Ti–Mn–Co–Ni–Al–C system and consolidated using spark plasma sintering (SPS) technique. Thermodynamic analysis predicted an adiabatic temperature of 1830 K, while experimental SHS reached 1550°C with rapid heating (1720°C/s) and cooling (2.8°C/s) rates. X-ray diffraction identified titanium carbide, FCC Ti–Mn–Co–Ni alloy, and minor amount of Mn2Ti intermetallic compound after the combustion synthesis. SEM/EDS revealed a porous, sponge-like SHS microstructure with bimodal particle-size distribution, evolving into a dense, well-bonded composite after SPS, with fine TiC uniformly dispersed in the metallic matrix. The intrinsic reactivity of SHS powders made them particularly suitable for spark plasma sintering, enabling rapid densification while preserving the fine TiC reinforcement and the entropy-stabilized FCC metallic matrix.
In this study, porous hollow cylinders based on β-SiAlON were produced via self-propagating high-temperature synthesis (SHS). The synthesis process involved two stages: (1) the preliminary structuring of a powder mixture of silicon, aluminum, and microsilica, with the incorporation of reinforcing basalt fibers into the porous reactive blanks, and (2) the nitridation of these blanks through SHS. The investigation examined the effect of the cylinder inner diameter on nitrogen content, burning velocity, maximum combustion temperature, porosity, gas permeability, compressive strength, and the phase composition of the products. The microstructure of the combustion products was also analyzed. For reaction blanks with an outer diameter of 90 mm, the combustion reaction could be initiated when the inner diameter was 50 mm or less. The porosity of the resulting β-SiAlON-based materials ranged from 49.5 to 51.8
