Reaction mechanism of core–shell Al@SiO2 nanoparticles from molecular dynamics simulations. (1st December 2022)

• Record Type: Journal Article
• Authors: Zhang, Jinping; Wang, Erping; Yu, Chunlai; Xie, Jingpei; Tang, Cuiming; Jia, Yu
• Is Part Of: Modelling and simulation in materials science and engineering. Volume 30:Number 8(2022)
• Publication Date: 2022-12-01
• Subjects: molecular dynamics -- reactive force field -- nanothermites -- core–shell structure -- reaction mechanism; Materials -- Mathematical models -- Periodicals; Matériaux -- Modèles mathématiques -- Périodiques; Materials -- Mathematical models; Periodicals; 620.00113
• DOI: 10.1088/1361-651X/ac9d55
• Languages: English
• ISSNs: 0965-0393

Abstract

Abstract: Nanothermites play an important roles in both civil and military fields. In this paper, using molecular dynamics simulations with reactive force field (ReaxFF), we study the thermally induced reactions of core–shell Al@SiO2 nanoparticles to elucidate the underlying reaction mechanism between Al and a metallic oxide. Core–shell Al@SiO2 nanoparticles undergo a four-stage explosive reaction after being heated to the ignition temperature. They are, in sequence: (i) Heat is released from the core–shell interface to Al core, and Al core begins to melt. (ii) The melted Al core accelerates the redox exothermic reaction, producing a pure Si shell. (iii) The Si shell moves towards the center of the system under electric field induction, and the distorted Aln O (n = 4, 5) clusters are ejected from the system's surface. (iv) The detonation of the nanoparticles, and the formation of final products. Notably, the electric-field-induced Al atoms diffuse faster than the O atoms throughout the reaction. Our findings provide a reference guide for the reactions of nanothermites.