The effect of nanoparticles on the microstructure of alkanes: A molecular dynamics study

• Published in: Journal of molecular liquids 2020-07, Vol.309, p.113162, Article 113162
• Main Authors: Wang, Xuzhe, Sun, Lei, Zhang, Xuelai, Zhang, Shaozheng, Wang, Jifen, Zhang, Yongyichuan
• Format: Article
• Language: English
• Subjects: Micro structure; Molecular dynamics simulation; Nanoparticles; PCM
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2020.113162

In order to explore the influence of nanoparticles on the microstructure of phase change materials in alkane systems, five different models were studied by molecular dynamics simulation. Eicosane is used to represent paraffin. One of the models was pure eicosane as a control group. The other four models mix four different nanoparticles of Ag, Cu, Al and Fe in eicosane. The mean square displacement, self-diffusion coefficient, end-to-end distance distribution and radial distribution function of each model under different temperature fields were calculated by simulation. Studies have found that the self-diffusion coefficient of eicosane increases with increasing temperature. However, the presence of nanoparticles limits the development of self-diffusion coefficient of eicosane. Through the statistical analysis of the end-to-end distance distribution, it is concluded that the presence of nanoparticles has a certain binding effect on the eicosane molecule. The presence of nanoparticles causes the conformation of more eicosane molecules to change from a linear to a curved state. It is found by the statistics of the radial distribution functions that the presence of the nanoparticles increases the number of particles around the eicosane molecule compared to the number of particles in the unadded nanoparticle model, and the system becomes more compact. The results obtained in this paper hope to provide a certain reference value for exploring the influence mechanism of nanoparticles on organic phase change materials and contribute to the improvement of energy utilization efficiency. •Molecular dynamics simulation method was used to simulate the mixed system of nanoparticles and eicosane.•The presence of nanoparticles limits the self-diffusion coefficient of the eicosane molecular chain.•The presence of nanoparticles leads to more eicosane molecular conformations tending from a linear state to a bent state.•The presence of nanoparticles makes the system more compact.