Diffusive transport of water in magnesium chloride dihydrate under various external conditions for long term heat storage: A ReaxFF-MD study

Defect-driven water migration in MgCl2 tetra- and hexahydrates

“…Furthermore, the reported values are much higher than one would expect for crystalline materials in general and hydrates in particular: i.e. approximately 10 -10 m 2 /s at 300 K for water in a magnesium chloride nanoparticle 14 . It might well be that the predicted fast diffusive motion is stress facilitated as the calculations were done on dehydrating nanoparticles.…”

“…The potential of Molecular Dynamics (MD) simulations have hardly been used for mechanistic studies of water hopping in salt hydrates. Only quite recently attempts have been reported to use MD to simulate dehydration of MgCl 2 and MgSO 4 nano-particles 13,14 .…”

Study on the sorption mechanism of middle‐low temperature sorption thermal storage materials from the microscale simulation: A review

“…It can describe the continuous change of particle coordinates and interactions during the chemical process, which has advantages in larger systems and condensed phases. 37 ReaxFF, proposed by van Duin et al 21 in 2001 and continuously improved by Senftle et al, 38 is widely applied in the study of STSMs. 36,37,[39][40][41][42] It describes the interaction between atoms in the molecule system by BO.…”

“…The MD simulation by Bermudez-Garcia et al 64 showed that at low temperature (less than 200 K), the diffusivity of H 2 O in Co-MOF-74 was almost negligible, while in the range of 200 to 400 K, the diffusivity increased with the temperature. Pathak et al 37 used ReaxFF MD to study the water diffusion in MgCl 2 Á 2H 2 O on the two-dimensional periodic model. The results showed that the diffusion coefficient of pure magnesium chloride hydrate increased with the temperature, which was consistent with the results obtained by Arrhenius equation.…”

“…Real salt hydrate materials often have vacancy defects. Pathak et al 37 used ReaxFF MD simulation to study the diffusion rates of water molecules at 300 K in three types of defect MgCl 2 Á 2H 2 O supercell: 6 × 3 × 6, 6 × 6 × 6 and 12 × 3 × 12. The water diffusion rate decreased as the volume enlarging.…”