MOLECULAR DYNAMICS STUDY OF ENHANCED SPECIFIC HEAT BY MOLTEN SALT EUTECTIC (Li_2CO_3-K_2CO_3) DOPED WITH SiO_2 NANOPARTICLES

摘要

Molecular dynamics simulations were performed to investigate a eutectic mixture of Li2CO3-K2CO3 (62:38 by molar ratio) doped with SiO2 nanoparticles. Literature studies show one salt of the eutectic can form a needlelike nanostructure due to its interaction with a SiO2 nanoparticle. The formed nanostructure is known to enhance the specific heat of the mixture. Several experimental studies have shown the effect of the nanostructure on the effective specific heat of the mixture. However, no theoretical or computational studies have been reported to corroborate the experimental findings. In this study, a eutectic mixture of Li2CO3-K2CO3 was doped with several SiO2 nanoparticles and needle-like Li2CO3 nanostructures. The density and specific heat of the mixture was computed by molecular dynamics simulations. Results show that SiO2 nanoparticles have a minimal effect on the effective specific heat of the mixture, yet needlelike Li2CO3 nanostructures were shown to increase the effective specific heat of the mixture. In addition, multiple Li2CO3 nanostructures with a different size were used to understand the mechanism behind the enhanced effective specific heat.