Effect of Bismuth Oxide Particles Size on the Thermal Excitation and Combustion Properties of Thermite Systems

Abstract

The influence of Bi 2 O 3 particles size at the sub‐micron scale on the thermal excitation threshold and combustion performance of nano‐thermite systems was investigated. Three formulas were designed and prepared, Al(100 nm)/Bi 2 O 3 (170 nm), Al(100 nm)/Bi 2 O 3 (370 nm) and Al(100 nm)/Bi 2 O 3 (740 nm). The samples were characterized and tested by SEM, XRD, and DSC techniques. Electrical ignition and combustion experiments were performed. The results showed that with the increase of the particle size of Bi 2 O 3 , in the case of slow linear heating, the exothermic heat decreased (1051.2 J g −1 , 527.3 J g −1 and 243.6 J g −1 ) and the thermal excitation threshold temperature increased (564.52 °C, 658.1 °C and 810.9 °C). Simultaneously, the state of the thermite reaction correspondingly changed to solid‐solid, liquid‐solid and liquid‐liquid thermite reaction. In the case of rapid heating , the increase in particle size increased the excitation current (0.561A, 0.710A and 0.837A). During the combustion process, the thermite system with the smallest Bi 2 O 3 particle size showed the largest combustion rate, and that with the largest particle size had the longest combustion duration.

Hot Bridge-Wire Ignition of Nanocomposite Aluminum Thermite Synthesized Using Sol-Gel-Derived Aerogel with Tailored Properties for Enhanced Reactivity and Reduced Sensitivity

“…Table 5 represents a detailed description of the effect of the equilibrium ratio on the Al/Fe 2 O 3 combustion performance test, its conditions, and the related controlled, independent, and dependent variables. The balance ratio and burning rate of nano-Al/Fe 2 O 3 are influenced by factors such as particle size, additives, and composition [70,146,147]. These insights highlight the complex interplay of various components in determining the performance of nano-Al/Fe 2 O 3 .…”

Effect of pro‐oxidants on the aerobic biodegradation, disintegration, and physio‐mechanical properties of compostable polymers

“…The presence of Bi 2 O 3 under heating and/or sunlight accelerates the rupture in polymer chains by incorporating oxygen atoms in the carbon skeleton of polymers and converting the structure into carbon dioxide (CO 2 ) (Scheme 1b). 20,21 S C H E M E 1 Mechanism of polymer biodegradation in the presence of (a) Iron Stearate as pro-oxidant, (b) Bismuth oxide as metal oxide.…”

“…Moreover, it has been proven that Bi 2 O 3 has higher exothermic characteristics and photocatalytic activities than other pro-oxidant metal oxides, such as Fe 2 O 3 , CuO, and MnO 2 , which could contribute significantly to the photos-and thermos-oxidation processes of the polymers' heterostructure under visible light irritation. 16,20,21 Moreover, Bi 2 O 3 possesses many other workability characteristics as filler additives for packaging applications, including low density, low toxicity, high water vapor permeability, exceptional mechanical properties, bending resistance, and excellent x-ray shielding properties. 13,14 El-Khatib et al reported that the filler structure of Bi 2 O 3 particles could improve the morphological and mechanical properties of polypropylene (PP) films by reducing the voids in the polymers.…”

“…The presence of Bi 2 O 3 under heating and/or sunlight accelerates the rupture in polymer chains by incorporating oxygen atoms in the carbon skeleton of polymers and converting the structure into carbon dioxide (CO 2 ) (Scheme 1b). 20,21 Moreover, it has been proven that Bi 2 O 3 has higher exothermic characteristics and photocatalytic activities than other pro‐oxidant metal oxides, such as Fe 2 O 3 , CuO, and MnO 2 , which could contribute significantly to the photos‐ and thermos‐oxidation processes of the polymers' heterostructure under visible light irritation 16,20,21 …”

How Positioning of a Hard Ceramic Tib2 Layer in Al/Cuo Multilayers Can Regulate the Overall Energy Release Behavior

“…One of the most promising reactive materials emerged in the 2000s is nanothermite which combines a metal and a metal oxide at nanoscale to chemically release large amounts of heat. These nanoscale energetic materials possess high volumetric energy densities (up to 80 kJ.cm -3 ), high adiabatic flame temperatures (>2600 °C) and improved combustion properties by several times [14][15][16][17][18][19] compared to microscale counterparts. A number of factors, in addition to the components' (metal and metal oxide) nature, influence the combustion properties of these reactive materials: they include the components' size, their intimacy, the metal/metal oxide interfacial layer's nature and thickness, as well as the metal and metal oxide mass ratio, thus providing quite a few ways to manipulate the overall energetic performance.…”