Molecular dynamics simulation of the molar volumes and solubility parameters of straight alkanes

摘要

The straight chain n-alkanes used as core materials to fabricate nanoencapsulated and microencapsulated phase change of materials (PCM) have received much attention in recent years. The dissipative particle dynamics (DPD) simulation method has been emerged to investigate the encapsulated PCM from the perspective of mesoscopic. To obtain the Flory-Huggins and repulsion parameters, which is essential for the DPD study, the molar volume and solubility parameter of straight alkanes are investigated by using molecular dynamics (MD) simulation. The results showed that a linear relationship of molar volume (V) with carbon atom number (n) and simulation temperature (T) can be obtained as: V = -31.73 + 0.26T + 14.82n. A nonlinear relationship of solubility parameter (delta) with carbon atom number and simulation temperature can be described as: delta = 18.45-3.66 x 10(-2)n + 1.07T -1.20 x 10(-5)n(2) - 9.60 x 10(-2)T(2) - 2.49 x 10(-3)nT. The equations can be used as a reference for the further DPD simulation in n-alkanes based PCM system.