Influence Of Strong And Weak Hydrogen Bonds In Water On Raman Scattering

In recent years,water has been studied by more and more researchers.The Raman spectroscopy is the most effective tool for studying the interaction between water and water or water and other substances from the molecular level.Since the emergence of laser,Raman scattering has a broader space than before,for the material exploration provides a new way.In the present study,we based on the basic principle of Raman scattering,the influence of laser induced plasma shock wave on water structure and the influence of strong and weak hydrogen bonds on water Raman scattering.(1)Stimulated Raman scattering(PSRS)from water molecules in the air/water interfacial regions was studied when the laser-induced plasma bubble was generated at the interfaces.A characteristically lower Raman shift of OH stretching vibrational modes of water molecules at around 3000 cm-1 was observed,in which the mechanisms were possibly attributed to the strong hydrogen bond in a well-ordered water bilayer structure that was formed on a laser-induced plasma bubble surface.Two peaks were obtained by using 355 nm Nd: YAG pulsed laser on ice Ih under the condition of-15 ?.Similarly,using 514.5 nm continuous lasers acting on ice,we found that the stimulated Raman spectrum exhibited exactly the relatively strong constituents of the spontaneous Raman spectrum.By summing up the analysis,we can use the vibration mechanism of strong and weak hydrogen bonds to explain the stimulated Raman spectrum of ice Ih.It is because of the different hydrogen bond strength,resulting in changes in bond length,so the Raman shifts are different.We believe that there will be strong and weak hydrogen bonds in other phases of the ice.This conclusion can help us understand the structure and nature of water and ice better.(2)Stimulated Raman scattering(SRS)in liquid water and ice Ih using Nd:YAG laser is investigated.The spectrum of backward SRS in water is obtained.The spectrum shows an unexpected SRS peak at around 3453 cm-1 beside the normal peak,which is similar to the spontaneous Raman spectrum of ice VII.The ice VII phase willbe formed by laser-induced shockwave compression on liquid water.The Raman peaks appeared in liquid water and ice Ih are attributed to the effect of strong and weak hydrogen bonds(H bonds),which may be ubiquitous in other ice phases.