Numerical investigation of microcapsules of phase change materials with au nanoparticles: The effect of radius and the atomic ratio of Au nanoparticles on the thermal storage efficiency of the simulated structure

Abstract

The addition of nanoparticles (NPs) can change the thermophysical properties of materials. Hence, adding NPs to phase change materials (PCMs) can accelerate phase transition processes. Moreover, the NPs concentration changes can change the structures' dynamic and thermal properties. Thus, it is crucial to survey how the volume fraction (size and atomic ratio) of NPs affects the PCM's thermal behavior. In the current work, molecular dynamics (MD) simulation was used to examine the thermal behavior of PCM microcapsules containing gold NPs. These microcapsules were taken into consideration together with aminoacetaldehyde (C2H5NO) and bromohexadecane (BrC16) as PCM, and the effect of gold nanoparticle radius and atomic ratio on simulated structure's thermal behavior was investigated. The findings demonstrate that charging and discharging periods were shortened by increasing the radius and atomic ratio of gold NPs in the atomic microcapsule structure. The heat flux (HF), and thermal conductivity (TC), on the other hand, are increased by increasing the radius of NPs from 3 to 6 nm, reaching 299.43 W/m2 and 1.42 W/mK, respectively. Moreover, by increasing the atomic ratio of NPs from 0.01 to 0.05, HF and TC values increased to 300.08 W/m2 and 1.45 W/mK, respectively. Furthermore, increasing the radius and atomic ratio of gold NPs in the microcapsule structure increased viscosity and phase change time. The methods offered in this study might be used as a viable mechanism in application domains to improve the thermal efficiency of this structure.