Total reflection infrared spectroscopy of water-ice and frozen aqueous NaCl solutions

摘要: Liquid-like and liquid water at near the surface of water-ice frozen aqueous sodium chloride films were observed using attenuated total reflection infrared spectroscopy (ATR-IR). The concentration NaCl ranged from 0.0001 to 0.01 M temperature varied melting point down 256 K. amount brine interface with germanium ATR crystal increased salt temperature. Experimental spectra are compared calculated for a simplified morphology uniform layer between film. This allows in an experimental spectrum be converted thickness homogenous equivalent liquid. These ranges nanometer 260 K 170 nm close point. amounts over order magnitude less than predicted by equilibrium thermodynamic models, implying that vast majority fraction solutions may found internal inclusions, grain boundaries, like. Thus, solutes dissolved them available react atmospheric gases on surfaces snow ice not well described models which assume phase is located entirely surface.