Effect of Oxide Shell on Aluminium Nanoparticle Oxidation Using Molecular Dynamics Simulation

Molecular dynamics simulation using reactive force field (ReaxFF)potential was implemented to study the oxidation mechanism in aluminium particles with two different alumina shells. That is, without an oxide shell and with a 1 nm oxide shell. In particular, this research investigated the atomic diffusivity of the system on the oxide shell effect. The results showed that in the heating process, oxygen molecules were adsorbed on the surface of the shell and then diffused to the particle core as the heating temperature increased. The diffusivity of oxygen molecules in the aluminium core which causes the oxidation process to occur, shows that the particles without the oxide shell are faster than the particles with the oxide shell. Although after relaxation, there are similarities in having an oxide shell. However, the thickness is different. This shows that the coating on Al particles can inhibit the rate of oxidation. The thickness of the oxide shell also affects the rate of oxidation.

RSC Advances ◽  
2016 ◽  
Vol 6 (64) ◽  
pp. 59313-59318 ◽  
Author(s):  
Jinping Zhang ◽  
Yubing Si ◽  
Can Leng ◽  
Baocheng Yang

The heating and low temperature thermite reactions of the Al/SiO2 sandwich nanostructure are investigated by MD simulations in combination with the reactive force field. The results show that the melting temperature of this structure is ∼1400 K.


Author(s):  
Xunyan Yin ◽  
Minli Bai ◽  
Chengzhi Hu ◽  
Jizu Lv

Molecular dynamics simulation was performed to investigate pool boiling heat transfer of nanofluids on rough walls. Nanoparticle movement was calculated to investigate the physical mechanisms of boiling heat transfer. The simulated system consisted of four regions: vapor argon, liquid argon, solid copper, and copper nanoparticles, and three cases were considered: base fluids (case A), nanoparticles far from the wall (case B), and nanoparticles near the wall (case C). Boiling heat transfer was enhanced by the addition of nanoparticles, and the enhancement increased with increasing heating temperature. Case C showed that nanoparticles were adsorbed on the nonevaporated film and did not move with the fluids. Thus, nanoparticles enhanced heat and energy transfer between the wall and fluids. Case B showed that nanoparticles moved randomly in the fluid area, which enhanced heat transfer within the fluid.


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