화학공학소재연구정보센터
Journal of Chemical and Engineering Data, Vol.65, No.2, 385-395, 2020
Effect of Zwitterionic Molecules on Ionic Transport under Electric Fields: A Molecular Simulation Study
Zwitterionic molecules can associate with both cations and anions in electrolytes. This ability can be leveraged to manipulate ionic associations and transport if we understand the related mechanisms. We investigate the effect of zwitterionic molecules on ionic associations and transport in the electrolytes composed of 1:1 Li salts (anions: [TESI](-) and [BETI](-)) and zwitterionic molecules containing imidazolium and sulfonate groups under 0-1.1 V/nm electric fields using molecular dynamics simulations. The ionic associations and transport in the electrolytes are analyzed using Li+-zwitterion and Li+-anion radial distribution functions, association number and lifetimes, and diffusion coefficients of Li+, anion, and zwitterionic molecules. The simulation results show a close correlation between the ionic association and transport. Small Li+ ions and large anions diffuse at the same level with the presence of zwitterionic molecules. The electric field must be stronger than a threshold to influence diffusion and associations of ions and zwitterionic molecules.