Hydrogen bonding network dynamics of 1,2-propanediol-water binary solutions by Raman spectroscopy and stimulated Raman scattering.

Raman spectroscopy and stimulated Raman scattering (SRS) were used to investigate the hydrogen bonding (HB) network in 1,2-propanediol (1,2-PD)-water binary solutions. Abnormal changes in hydrogen bonds (HBs) were detected when V1,2-PD (volume fraction of the1,2-PD) was 0.4. In the case of Raman spectroscopy, the HB strength of water is weakened and then strengthened with the increase of 1,2-PD volume fraction. In the case of SRS, two new peaks at 3283 cm-1 and 3319 cm-1 were appeared, which demonstrated the appearance of ice-like structures near the methyl group and the weakening of HBs. Based on these phenomena, the HB structure of this binary system underwent a transition from H2O-H2O to H2O-1,2-PD when the V1,2-PD was 0.4 as V1,2-PD increased. This work serves as a reference value for the study of HB networks in alcohol-water binary solutions.