Molecular simulations and FTIR spectroscopic studies on the hydration, dynamics, and dielectric properties of the aqueous potassium carbonate system at various temperatures from 278.15 K to 373.15 K

Abstract

Potassium carbonate is widely used in various industries such as soap, glass production, and chemical processes due to its effectiveness in neutralizing acids as a strong base. Furthermore, computer simulations play a crucial role in understanding the structural and dynamic properties of electrolytic systems. In this work, the hydration structure and the dynamic and dielectric properties of K₂CO₃ ion pairs in aqueous medium were studied using molecular dynamics simulations. We employed the CHARMM36.FF force field combined with the TIP3P water model to simulate our system. The radial distribution function (RDF) was calculated to analyze the structural behavior of various ion pairs, while the dynamic and dielectric properties of this electrolytic system were assessed by simulating the self-diffusion coefficient and dielectric constant at temperatures ranging from 278.15 to 373.15 K. The obtained simulation results showed that temperature exerts disruptive effects due to thermal agitation, leading to an increase in kinetic energy. This increase promotes structural modifications in the distribution of hydrogen bonds and causes apparent changes in the transport and dielectric behaviors of this electrolytic system. Additionally, we compared and validated our structural results with Fourier-transform infrared (FTIR) spectroscopy data across the various vibrational modes of the K₂CO₃(aq) binary system at a concentration of 1.07 mol.kg^-1 and T = 298.15 K.