Search

EG (ethylene glycol) is a good model system for the study of the fundamental hydrogen bonds in aqueous solutions. Using Raman spectroscopy, we have investigated the EG volume fraction induced variation in the hydrogen bonding interactions and conformations of EG-H 2 O (water) binary solutions. New hydrogen bonding networks is evidenced by the appearance of remarkable changes in Raman spectra and the full width at half maximum (FWHM) when the mixing volume ratio is 0.5. The H-bond in water molecules firstly strengthened and then weakened with the increasing concentration of EG. Meanwhile, the dominant association structure also changed from H 2 O-H 2 O to EG-H 2 O in binary solutions in this process. We provide a simple but effective method for studying EG-H 2 O binary solutions. It also has exciting potential prospects and can be easily extended to other mixing situations., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The Raman spectra of ice Ih (H 2 O and HDO) in the temperatures range from 253 to 83 K are measured. The results show that Raman peaks shift to low- or high-wavenumber due to the influence of temperature on hydrogen bonds dynamics. Importantly, Raman shifts are linear relationship with temperatures and its slope fully reflects the change of hydrogen bonds length. Finally, Raman intensity of ice Ih dependent on temperatures are also discussed., (Copyright © 2019. Published by Elsevier B.V.)

Stimulated Raman scattering (SRS) of liquid water and heavy water have been investigated using Nd:YAG laser. The SRS spectra of liquid heavy water indicate that ice-VII and ice-VIII structures are formed by shock-induced compression (SIC) in forward and backward directions, respectively. Simultaneously, the SRS spectra reveal of liquid water that only ice-VII structure is formed in the backward direction. The difference in ice structures formed by SIC in liquid water and heavy water could be attributed to the effect of the hydrogen bond quantum nature with H + . SRS spectra of 2M NaOH water solution with ice-VII and ice-VIII structures have been successfully obtained in forward and backward, respectively, as OH - greatly reduce the quantum nature of hydrogen bonds by neutralizing H + in water. The hydrogen bond quantum nature is important for understanding isotope calibration test structure and isotopic effect., (Copyright © 2017 Elsevier B.V. All rights reserved.)

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 3063cm -1 (2438cm -1 ) in the recorded Raman spectra are assigned here to the OH (OD) bond stretching vibrations and they are compared with the corresponding bands observed at 3124cm -1 (2325cm -1 ) in the Raman spectrum of ice Ih. Our spectroscopic observations have indicated that the structure of water and deuterated water molecules on borosilicate surface is similar to that of ice Ih (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., (Copyright © 2018. Published by Elsevier B.V.)

Raman spectra of ethanol-water binary solutions have been observed at room temperature and atmospheric pressure. We find that with increasing ethanol concentration, the symmetric and asymmetric OH stretching vibrational mode (3286 and 3434cm -1 ) of water are shifted to lower frequency and the weak shoulder peak at 3615cm -1 (free OH) disappears. These results indicate that ethanol strengthens hydrogen bonds in water. Simultaneously, our experiment shows that Raman shifts of ethanol reverses when the volume ratio of ethanol and the overall solution is 0.2, which demonstrates that ethanol-water structure undergoes a phase transition., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The Raman spectra of different concentrations of NaOH solutions have been successfully obtained at normal pressure by cooling. The results indicate that the icing point and the ice phase transition temperature of NaOH solutions decrease with increasing concentrations. Particularly, the different concentrations (2, 4, 6 or 8 and 12M) take place the liquid- III- Ih, liquid- V- Ih, liquid- VI- XV and liquid- IX- VI phase transition, respectively. In addition, the three peaks of around 3524, 3580 and 3624cm -1 appear spectra of the NaOH solutions at low temperature., (Copyright © 2017 Elsevier B.V. All rights reserved.)