RAMAN-SPECTROSCOPIC STUDY ON WATER IN POLYMER GELS

Raman spectroscopic study on water in cross-linked polyacrylamide (PAAm) gels was carried out. The relative intensity of a peak corresponding to the collective mode of O-H stretching of water molecules in the polymer gels in comparison with that of free water significantly decreased with an increase in the degree of cross-linking. The relative intensity of the collective band in the solution of linear polyacrylamide was relatively larger than that of the polymer gel system at the same concentration. The contribution of small water domains included in the polymer gel (so-called interstitial water) to the change in the Raman spectra was suggested.