Mid‐infrared spectroscopy study of aqueous solution of ethylene glycol using chemometrics analysis and two‐dimensional correlation spectroscopy

Abstract 1, 2‐Ethandiol (ethylene glycol, EG) and its mixtures with water (W) have widespread industrial and biological applications due to their special physiochemical properties. In this study, two‐dimensional correlation spectroscopy and chemometrics analysis of infrared spectra are used to characterize structural features of EG–W binary solutions. Three distinctive regions are observed with diverse contributions of hydrophobic backbone (CH 2 groups) and hydrophilic (OH functional) groups. Both groups are simultaneously considered to characterize local structure in each triple region. The aqueous solutions of EG are changed from EG‐like ( x w ≤ 0.27) to W‐like solution ( x w > 0.83), where x w is W mole fraction. The wide range of EG–W mixtures (0.27 < x w ≤ 0.83) are stabilized by –OH … O (proper hydrogen bonded) and –CH … O (improper hydrogen bonded). Also, trend and relative equilibrium concentration variation of W, EG, and identified cluster are used to propose chemical model of EG–W interaction.