title: Structure and dynamics of water in mixed solutions including laponite and PEO.
abstract: 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.
authors.affiliation: Department of Applied Chemistry, Meiji University, Kawasaki 214-8571, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Morikubo
authors.forename: Yurina
authors.initials: Y
authors.lastname: Sekine
authors.forename: Tomoko
authors.initials: T
authors.lastname: Ikeda-Fukazawa