Department of Applied Chemistry, Meiji University, Kawasaki 214-8571, Japan.
J Chem Phys. 2011 Jan 28;134(4):044905. doi: 10.1063/1.3533233.
To investigate the structure and dynamics of water in mixed solutions including laponite clay particles and poly(ethylene oxide) (PEO), we measured the Raman spectra of the mixed solutions in the temperature range 283-313 K. The results show that the vibrational energies of the O-H stretching modes in the mixed solutions depend on the water content and temperature. The energy shifts of the O-H stretching modes are attributed to changes in the water structure. By applying a structural model of bulk water to the spectra in the O-H stretching region, the local structures of water in the solutions were analyzed. The result shows that the formation probability of hydrogen bonds in the solutions decreases as the water content decreases. Laponite and PEO have effects to disrupt the network structure of hydrogen bonds between water molecules. Further, it was found that laponite and PEO cause increase in the strength of hydrogen bonds of surrounding water,although the strength of the hydrogen bonds increases with the order water-laponite < water-water < water-PEO. It is concluded that water in laponite-PEO mixed solutions has a less-networked structure with strong hydrogen bonds compared with bulk water.
为了研究包括皂土颗粒和聚（环氧乙烷）（PEO）在内的混合溶液中的水的结构和动力学，我们在 283-313 K 的温度范围内测量了混合溶液的拉曼光谱。结果表明，混合溶液中 O-H 伸缩振动模式的振动能量取决于水含量和温度。O-H 伸缩振动模式的能量位移归因于水结构的变化。通过将体相水的结构模型应用于 O-H 伸缩区域的光谱，分析了溶液中水分子的局部结构。结果表明，随着水含量的降低，溶液中氢键的形成概率降低。皂土和 PEO 会破坏水分子之间氢键的网络结构。此外，还发现皂土和 PEO 会增加周围水分子氢键的强度，尽管氢键的强度随着水-皂土<水-水<水-PEO 的顺序增加。结论是，与体相水相比，皂土-PEO 混合溶液中的水具有较少的网络结构和较强的氢键。
