STRUCTURED WATER MOBILE BELOW THE FREEZING-POINT IN AQUEOUS-SOLUTIONSOF A TRIPLE-HELICAL POLYSACCHARIDE SCHIZOPHYLLAN

Aqueous solutions of schizophyllan are known to undergo a sharp order- disorder structure transition, where the ordered structure is formed o f the side chains of the polysaccharide along with nearby water molecu les around its helix core. The structured water in the ordered state i s positionally fixed but rotates reacting with an electric field of ab out 100 MHz as detected by time-domain reflectometry. The same method was extended to a wide temperature range between -20 and 30 degrees C encompassing the freezing point of about -6 degrees C. A 17.8 wt% D2O solution showed both free and structured water dispersions at 0 degree s C, but only the latter one below the freezing point. Thus we conclud ed that the structured water around the helix core remains unfrozen an d mobile even when the system is frozen and no free water exists.