Molecular dynamics simulation of palmitic acid molecular passivation affecting the surface activity of aluminum...

It has been discovered that the surface passivation degree of aluminum nanoparticles (ANPs) is closely related to the melting point, and it is possible to quantify the equivalent relationship between the surface passivation properties of ANPs coated with organic acids and ANP oxidation. The Large-Scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) is applied to study the passivation mechanism of palmitic acid adsorption on the ANP surface, and further completed the molecular dynamic simulation of ANP phase transition with different palmitic acid-coating degrees and oxidation degrees. It is found that the microscopic angle quantification of palmitic acid using single-molecule simulations is very effective for the passivation simulations of ANP surfaces. However, in the macroscopic quantitative verification simulation of ANPs' melting point, it is found unexpectedly that the melting point of ANPs would decrease with the increase in palmitic acid coating degree. Interestingly, this was exactly the opposite of the expected trend. Therefore, we also drew the conclusion that although the organic acid coating completed the surface passivation of ANPs on the micro level, it increased the reactivity of ANPs on the macro level.