Ionization Equilibrium of Water Molecule Dominated Ethanol-water Binary Solution Self-assemble

Abstract

Water and ethanol are conventional solvents, the anomalous physio-chemical properties of water ethanol binary solution have drawn intensive research. The unidirectional impedance evolution of ethanol-water binary solution in time domain was discovered through electrochemical impedance spectroscopy. Binary solution with different volume ratios has various self-assembly rates indicate ionization equilibrium of water molecule dominate the dynamic self-assembly process of water ethanol binary solution. Combined with molecular dynamics simulation and Raman Spectroscopy, we elucidated that this self-assembly behavior was driven by hydrogen bonding between water as proton donor and ethanol as proton receptor under water ionization, the bond length (162 pm). Different electrolytes addition in binary solution were applied to shift ionization equilibrium of water directionally, and subsequent specified self-assembly evolution was observed to prove the above hypothesis. We proposed the self-assembly mechanism of ethanol-water binary solution is relevant to ionization equilibrium of water for the first time, such perspective may provide some insight to understand the dynamic structural organization of ethanol-water and other binary solutions.