Vibrational spectroscopy is a powerful tool for probing confinement effects that can occur in soils and rocks. The simulation studies assist in correlating the spectroscopic features of electrolytes in confined environments with molecular-level details. The results will assist in the development of a molecular-level picture of the spectroscopic signatures and dynamical properties of confined electrolytes. We use molecular dynamics simulations to simulate the linear infrared (IR) and Raman spectra for electrolytes NaCl, NaBr and NaI in isotopically dilute HOD in D<sub>2</sub>O confined in hydroxylated amorphous silica slit pores of widths 1- 6 nm. The effect of slit pore width and concentration of the electrolyte on the vibrational spectra were investigated. We also generate free energy profiles of the cations and anions as a function of position in the pore. These are compared and contrasted with the vibrational spectroscopic signatures. The results provide insight into the effect of confinement on solution properties and the information that can be gained from vibrational spectroscopy probes.

Simulations of vibrational and solvation properties of nano-confined electrolyte solutions

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.