TURBIDITY STUDY OF SPINODAL DECOMPOSITION OF AN N-ISOPROPYLACRYLAMIDEGEL

The kinetics of the spinodal decomposition of the volume phase transit ion of an N-isopropylacrylamide gel is studied using a turbidity techn ique. Three stages were identified: the early stage, the transition st age, and the frozen stage. The early stage can be explained by Cahn-Hi lliard-Cook's theory. In the transition stage, the cascading network s egment association process causes the turbidity to increase faster tha n the early stage. The transition stage is characterized by its turbid ity growth peak. The final stage, the frozen stage, is characterized b y the high turbidity and vanishing turbidity growth rate. In this stag e, the spatial concentration variation is frozen and the system enters a semistable state.