Interfacial water on hydrophilic surfaces is considered as a key factor determining the local organization of the hydrogen-bonded network and the associated physicochemical properties of aqueous media. In this work, a comprehensive study of the
interface-induced structuring of water was presented upon contact with polymeric and oxide materials-the
Nafion ion-exchange membrane, the water-soluble polyelectrolyte
carboxymethyl cellulose (CMC), and silicon dioxide (SiO۲). Samples were prepared by contacting highly purified water (≥۱۸.۲ MΩ cm) with the corresponding interfaces for ۰-۶۰ h and analyzed using LC microscopy, FTIR spectroscopy, Raman spectroscopy, and UV-Vis spectrophotometry, as well as changes in acid-base and electrochemical parameters (pH, ORP, conductivity, and resistivity). LC microscopy revealed the formation of stable near-surface textures and domain structures absent in the control water, indicating mesoscopic heterogeneity of the interfacial aqueous phase. Spectroscopic data (FTIR ν(OH) and Raman in the range of ۳,۲۰۰-۳,۶۰۰ cm-۱) demonstrated consistent changes in the shape and position of OH bands, indicating a redistribution of the contributions of "bound" and "free" OH components and a rearrangement of the hydrogen-bonded network near the interface. Electrochemical measurements showed that
Nafion causes pronounced acidification and an increase in ORP with a decrease in electrical conductivity and an increase in resistivity (pH ۵.۸۸→۴.۲۴; ORP ۶۶→۱۶۰ mV), while CMC and SiO۲ lead to a shift in pH toward the alkaline region and an increase in electrical conductivity, most pronounced for SiO۲. The combined results supported a working mechanism in which hydrophilic functional groups and surface charge regulation form an electrical double layer, inducing the orientation of water dipoles and the cooperative rearrangement of an extended hydrogen-bonded network, resulting in spatial pH/ionic gradients. The obtained intermethod correlations confirmed the universality of the interface effect for various classes of hydrophilic materials and provided a basis for the development of applied systems utilizing
interfacial water in membrane processes, water treatment, and controlled aqueous environments.
