About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Materials and Chemistry for Molten Salt Systems
|
| Presentation Title |
Thermodynamics of Melting-induced Hydration in Molten Salts |
| Author(s) |
Hyeonwoo Kim, Seol Kim, Eun-Young Choi, Sangtae Kim |
| On-Site Speaker (Planned) |
Hyeonwoo Kim |
| Abstract Scope |
Residual water in molten chloride salts can generate corrosive hydrolysis products and accelerate material degradation in molten salt reactors. Although thermal dehydration is commonly applied before melting, our Karl Fischer titration measurements revealed that the water concentration in some chloride salts increases upon solid-to-liquid transition. Here, we use atomistic simulations to clarify the thermodynamic origin of this melting-induced rehydration. Neural-network interatomic potentials were employed to calculate the hydration free energies of LiCl, NaCl, KCl, MgCl2, CaCl2, and ZnCl2 in solid and liquid states near their melting points. Free-energy decomposition reveals that hydration becomes more favorable after melting for most salts, mainly because the liquid-phase reduces the entropic penalty associated with water confinement. ZnCl2 is an exception: its rigid network-forming melt suppresses water mobility and rehydration. These results show that rehydration is controlled by the interplay between hydration entropy and molten-salt structure, providing insight for molten-salt purification and corrosion mitigation. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Modeling and Simulation, Nuclear Materials, Computational Materials Science & Engineering |