Influence of spherical and cubical geometry of silver nanoparticles on thermal characteristics

Antibacterial activity of silver nanoparticles with spherical or cubic shapes in medical science will render it attractive. Considering the physical characteristics like thermal features as crucial factors are essential for choosing nanospheres or nanocubes with respect to operating temperature and stability. Therefore, this research probes the melting process, the surface premelting points (Tsm), the complete melting point (Tm), the phase transition, and the specific heat capacity at a constant volume (Cv) of silver nanospheres and nanocubes via a molecular dynamics approach. Regarding these aims, different approaches have been employed to achieve high accuracy. The results indicate that the geometry of nanoparticles dramatically influences the Tsm and Tm, and nanocubes have lower Tsm and Tm than nanospheres. Moreover, the nanocubes are melted from corners toward the cube center while the nanospheres melt in the radius direction. In contrast, Cv of silver nanospheres and nanocubes is almost identical, demonstrating that the Cv is independent of geometry. In addition, the values of Cv for the nanoparticles are close to the bulk value, which indicates that by changing the dimension of silver from bulk to nanoparticles, the specific heat capacity will not change, and this value is an intensive property.