Local Solvation Behavior in Micro-heterogeneous and in Phase-separated Aqueous Alcohol Solutions

This research paper delves into the ongoing discourse about the correlation in the structural and dynamic attributes of hydrogen bond (HB) networks within alcohol-water binary mixtures. Employing Terahertz time-domain spectroscopy (TTDS) and Terahertz-Fourier transform infrared (THz-FTIR) spectroscopy, we conduct an in-depth exploration of the intermolecular roto-vibrational modes of water. Through this analysis, we extract relevant insights concerning the configuration of the HB network. Our study reveals a comprehensive comprehension of the variances in structure and dynamics within the HB network in response to alterations in solute concentration. We have considered both micro-scale and macro-scale for partially water-soluble alcohol phases. Furthermore, we have considered the influence of hydrophobicity and the macroscale self-aggregation tendencies of alcohols, culminating in a holistic viewpoint of the intermolecular networks within these binary mixtures. We found that the delicate equilibrium between local homo-molecular structures with the cross-molecular solvation configurations leads to micro/macro scale self-aggregation that exerts significant influence over the collective behavior of the mixture.