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Liquid water is a complex system consisting of ice‐like and quartz‐like structure based on the classic two‐state model. Although lots of theoretical work have been developed about this model, the experimental evidences are still needed. Herein, a 355‐nm pulse laser is employed to excite stimulated Raman scattering (SRS) of liquid water both in bulk and on surface, with the generation of shockwave‐induced dynamic high pressure. Two characteristic features Raman peaks of both spontaneous Raman and SRS indicate the coexistence of two structures in localized water area. The ice‐like structure corresponds to ice Ih phase under the presented conditions, because the pressure dependence behavior of Raman shift agree well with the anomaly of diffusion coefficient of ice Ih phase, when the shock wave‐induced dynamic high pressure forms. Two structures show different pressure‐dependent behaviors based on the SRS results; meanwhile, the distribution of two structures is different in bulk and on surface water. [ABSTRACT FROM AUTHOR]

Stimulated Raman scattering (SRS) in H2O2–H2O mixture solutions are obtained in forward and backward directions. Characteristic features peaks related to OH stretching vibrations of water are the appearance of three enhancement peaks in both directions. Simultaneously, the low‐wavenumber SRS peaks in water at 840 and 1,700 cm−1 are enhanced. The mechanism of enhancement is attributed to excess electron‐enhanced Raman scattering. The electron‐enhanced process is also discussed. [ABSTRACT FROM AUTHOR]

The structural forms of water/deuterated water molecules located on the surface of borosilicate capillaries have been first investigated in this study on the basis of the Raman spectral data obtained at different temperatures and under atmospheric pressure for molecules in bulk and also for molecules absorbed by borosilicate glass surface. The strongest two fundamental bands locating at 3063 cm −1 (2438 cm −1 ) in the recorded Raman spectra are assigned here to the O H (O D) bond stretching vibrations and they are compared with the corresponding bands observed at 3124 cm −1 (2325 cm −1 ) in the Raman spectrum of ice I h . Our spectroscopic observations have indicated that the structure of water and deuterated water molecules on borosilicate surface is similar to that of ice I h (hexagonal phase of ice). These observations have also indicated that water molecules locate on the borosilicate surface so as to construct a bilayer structure and that strong and weak intermolecular hydrogen bonds are formed between water/deuterated molecules and silanol groups on borosilicate surface. In accordance with these findings, water and deuterated water molecules at the interface of capillary have a higher melting temperature. [ABSTRACT FROM AUTHOR]

The structure of liquid water is strongly influenced by Si quantum dots (Si QDs). We employed Raman spectroscopy to investigate how Si QDs affect the icing point of water. In contrast with the Raman spectra of pure water, Raman spectra of Si QDs water solutions exhibit some distinct characteristic features. The Raman spectra present that liquid- ice I h phase transition takes place at 264 and 266 K in 5 and 2 nm Si QDs solutions respectively, which is higher than that of pure water (257 K). These phenomena are contributed to the electric field generated by Si QDs and the hydrogen bonds formed between silanol groups and water molecules. The results can open the way to understand the interaction between water molecules and quantum dots in some environments. • We employ Raman spectroscopy to study how Si QDs affect the icing point of water. • Si QDs can increase the icing point of water by H-bonds and electric field. • The icing point is dependent on the size of the Si QDs due to the suface effect. [ABSTRACT FROM AUTHOR]