Cluster-associate viscosity model of tin chloride in comparison with the Frenkel model

Determining the viscosity of inorganic molten compounds like tin chloride is critically important for material processing, chemical synthesis, and energy applications. However, experimental limitations have restricted the development of accurate viscosity models. This study tests a new cluster-associate model for predicting the viscosity of molten tin chloride across a wide temperature range. The model links viscosity to the structure and dynamics of molecular clusters in the melt. The aim of this study is to establish a correlation between viscosity and cluster formation within a liquid, using tin chloride as an example. The data were calculated using a newly developed equation based on the concept of randomized particles. The temperature range studied was from the melting point to the boiling point. To verify the accuracy of the cluster-associate model, it was compared with the Frenkel equation using logarithmic coordinates. Simulations were performed on tin chloride, which yielded results showing a linear relationship between the degree of cluster association and the activation energy of fluidity. The proportionality coefficient reflects the activation energy associated with a single cluster. The Frenkel equation in the logarithmic coordinate scale was compared with the cluster-associate model. The functional dependence and correspondence of these models are indicated by their high coefficient mutual correlation. The proposed viscosity model underwent testing for the entire liquid state range of the substance, and calculations confirmed its validity. This enables reliable use of the suggested model for both high- and low-temperature extrapolation, including the critical point region.