Molecular dynamics study on the impact of the development of dendritic nanostructures on the specific heat capacity of molten salt nanofluids

A dendritic nanostructure has been observed to form when one salt of the eutectic salt mixture comes into contact with a SiO2 nanoparticle, according to investigations in literature. The effective specific heat capacity of the molten salt nanofluids has been reported to be influenced by the presence of these nanostructures. Some reported studies experimentally confirmed that these nanostructures can increase the specific heat capacity of molten salt nanofluids. However, there have been no detailed theoretical or computational investigations to validate the experimental results. In this study, molecular dynamics simulations were used to investigate a eutectic mixture of Li2CO3 and K2CO3 (62:38 M ratio) doped with SiO2 nanoparticle surrounded by dendritic Li2CO3 nanostructures. The mixture's density and specific heat capacity were determined using molecular dynamics simulations. The nanofluids only containing nanoparticles did not show any significant changes in its density or specific heat capacity. The effective specific heat capacity of the mixture was improved, and density of the mixture was decreased by the presence of SiO2 nanoparticles surrounded by dendritic Li2CO3 nanostructures. The high specific surface energy associated with the large surface areas of the implanted nanoparticles as well as the dendritic nanostructures created by nanoparticle addition can explain the observed enhancements in specific heat capacity. •Salt dendritic nanostructures can be formed near nanoparticles.•This phenomenon enhances the specific heat of molten salt nanofluids.•Molecular dynamics simulation was employed to study this phenomenon.•Only nanoparticles did not show density or specific heat capacity variations.•Including salt dendritic nanostructures showed density drop and heat capacity rise.