Volume 110, Issue 7, 15 February 1999
Index of content:
- POLYMERS, BIOPOLYMERS, AND COMPLEX SYSTEMS
Heterogeneous percolation-to-cluster transition in phase separation of an off-critical polymer mixture110(1999); http://dx.doi.org/10.1063/1.478229View Description Hide Description
Phase separation kinetics of an off-critical polymer mixture involving percolation-to-cluster transition (PCT) was investigated by time-resolvedlight scattering and by transmission optical and electron microscopies. The process involving a splitting of a single peak in the light scattering profile into a double peak was observed for the first time after the onset of PCT. Each peak changes with time according to different evolution modes, e.g., the first peak wave number evolved according to the power law of percolated structures while the time evolution of the second peak wave number is very slow, which corresponds to the growth of cluster of the droplets after PCT. Furthermore, the real space pictures and the light scattering analysis reveal that a cluster of the small spherical droplets and the locally percolating domains coexist for a very long time. The percolating domains are larger than the small droplets, minor in volume fraction, and formed in bulk and they are developed into sheet-like grains with their surfaces parallel to the glass surface.