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Porous Si/Al-Si spherical powders with controllable structure and superior reactivity via dealloying of Al-Si.
- Source :
-
Chemical Engineering Journal . Mar2024, Vol. 483, pN.PAG-N.PAG. 1p. - Publication Year :
- 2024
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Abstract
- [Display omitted] • Spherical powders containing Si with tailorable porosity were originally obtained. • Prepared micro-size porous samples consisted of nano-sized channels for reaction. • The energetic kinetics of prepared fuels outperformed Al nanoparticles. • Discrepant reaction mechanism for AlSi@pSi at different circumstances was found. Energetic porous fuels are attractive for their high reactivity. In this study, porous silicon/aluminum–silicon (pSi/AlSi@pSi) powders were prepared via dealloying Al-Si alloy. Results demonstrate that pSi and AlSi@pSi with evenly distributed pores and tailorable porosity were obtained. AlSi@pSi shows a core–shell structure with Al-Si alloy core and porous Si shell. Thermal properties indicate that consistent with its core–shell structure, the oxidation of AlSi@pSi can be considered as a combination of pSi and Al-Si alloy. The main oxidation is kicked in by the reaction of the Al-Si alloy core, followed by the intense reaction of the porous Si shell. The combustion characterization demonstrates that the dramatically improved reactivity of porous samples is attributed to the ultra-high kinetics of porous Si outperforming nano-sized aluminum (n-Al). The shorter ignition delay and combustion duration of porous samples than Al-Si alloy and n-Al result from the lower apparent activation energy (E 0) and the low initiation oxidation temperature for porous Si. The different oxidation processes for AlSi@pSi under thermal oxidation and combustion owe to the high oxidation peak temperature and low E 0 of porous Si. Above all, the prepared porous fuels with tailorable porosity and superior reactivity than n-Al are promising fuels in energetic materials. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 13858947
- Volume :
- 483
- Database :
- Academic Search Index
- Journal :
- Chemical Engineering Journal
- Publication Type :
- Academic Journal
- Accession number :
- 175679813
- Full Text :
- https://doi.org/10.1016/j.cej.2024.149310