Fabrication and Kinetics Study of Nano-Al/NiO Thermite Film by Electrophoretic Deposition

Abstract

Nano-Al/NiO thermites were successfully prepared as film by electrophoretic deposition (EPD). For the key issue of this EPD, a mixture solvent of ethanol-acetylacetone (1:1 in volume) containing 0.00025 M nitric acid was proved to be a suitable dispersion system for EPD. The kinetics of electrophoretic deposition for both nano-Al and nano-NiO were investigated; the linear relation between deposition weight and deposition time in short time and parabolic relation in prolonged time were observed in both EPDs. The critical transition time between linear deposition kinetics and parabolic deposition kinetics for nano-Al and nano-NiO were 20 and 10 min, respectively. The theoretical calculation of the kinetics of electrophoretic deposition revealed that the equivalence ratio of nano-Al/NiO thermites film would be affected by the behavior of electrophoretic deposition for nano-Al and nano-NiO. The equivalence ratio remained steady when the linear deposition kinetics dominated for both nano-Al and nano-NiO. The equivalence ratio would change with deposition time when deposition kinetics for nano-NiO changed into parabolic kinetics dominated after 10 min. Therefore, the rule was suggested to be suitable for other EPD of bicomposites. We also studied thermodynamic properties of electrophoretic nano-Al/NiO thermites film as well as combustion performance.

Towards Safer Primers: A Review

“…Powdered energetic reactant mixes can be added to initiators with their wide range and tunable reaction rates, temperatures and gas evolution. This depends on multiple factors such as the composition, stoichiometry, particle or layer size for solid-state mixes and distribution (layers, particles, vertical 1D or 2D periodic structures) [19,73]. The reaction speed is tuned by changing the surface area, particle size or thickness of thin film layers and reaction temperatures are also dependent on rate, with higher temperatures reached from faster reactions [54,56,63].…”

3D ordered macroporous NiO/Al nanothermite film with significantly improved higher heat output, lower ignition temperature and less gas production

“…These disadvantages lead to a relatively low energy output, 1000 J·g -1 , only 29% of the theoretical reaction heat from the NiO/Al system. In the work published by Zhang et al [18], the energy release is still low from nano-NiO/Al thermite film fabricated by electrophoretic deposition with controllable film thickness. This is induced by some inevitable impurities from the dispersion system.…”

“…Nanothermites have been applied in broad fields, such as microelectro-mechanical system (MEMS) [2,11], thermal batteries, gas generators [12][13][14], and microthrusters [15,16]. In some particular applications, for example microinitiators, little component vibration and short flow disturbance are required [17,18]. Therefore, it is desirable to generate high heat output but little gas releasing from thermite reaction.…”

“…Recently, there were some investigations on the preparation and properties of NiO/Al nanothermite [18,19,22]. In the literature, the composite of Al nanoparticles (Al-NPs) and NiO nanowires have been synthesized through ultrasonic mixing method, and the influence of NiO mass ratio over Al-NPs are widely discussed [19].…”

Preparation of SiCNFs Composite Anode by Electrophoretic Deposition (EPD)

“…As the increase of the deposition time, the deposition will gradually arrive at a saturation point with less increase. Fig.2.22 [106] shows a typical example of Al/NiO coating in the mixture of ethanol-acetylacetone (1:1 in volume) with the increasing deposition time. The linear relation between deposition mass with deposition time in short time and parabolic relation in prolonged time can be observed.…”