Effect of Different Salt Concentrations on Dimethyl Sulfoxide (DMSO) Nanocluster Structures by Molecular Dynamics Simulations

We performed MD simulations to examine dimethyl sulfoxide (DMSO) nanocluster structures in NaCl aqueous solution with different concentrations (0.45 g/100 mL, 0.9 g/100 mL, 1.8 g/100 mL, 2.7 g/100 mL, and 3.6 g/100 mL). Results showed that interaction between Na⁺ and DMSO at the first solvation shells was weakened due to acceleration rotational influence of ion driven by NaCl concentration. We investigated the tetrahedral order parameter and average H-B number of water molecules. These results indicated that NaCl influenced the solvation structure of water cluster, but that of DMSO was not affected by NaCl. We also found that Na+ was prior solvated by water solution in these mixture systems, and Cl⁻ only existed in the water cluster in our simulation systems. Consequently, we herein proposed a decentralized model that depicts microphysical structure images of DMSO in NaCl aqueous solution systems.