Sy. Qi et Zg. Wang, WEAKLY SEGREGATED BLOCK-COPOLYMERS - ANISOTROPIC FLUCTUATIONS AND KINETICS OF ORDER-ORDER AND ORDER-DISORDER TRANSITIONS, Polymer, 39(19), 1998, pp. 4639-4648
We discuss the kinetics of order-order and order-disorder transitions
in weakly segregated diblock copolymers. A theory is developed based o
n the anisotropic fluctuations in the ordered phases. These fluctuatio
ns play two crucial roles: first, they determine the stability limit o
f the initial structure and, second, they are responsible for the emer
gence of new structures, whether these are the final equilibrium state
s or transient states during the transition. A linear stability analys
is allows us to identify the largest fluctuation modes under both equi
librium and nonequilibrium conditions. By combining the order paramete
r of the initial structure with the largest fluctuation modes into a s
implified multimode model we are able to describe qualitatively the fu
ll nonlinear evolution of the system after sudden temperature jumps be
yond the spinodal of the initial phase. Our theory successfully explai
ns our earlier results from direct Cahn-Hilliard-type numerical simula
tions. Our predicted kinetic scenarios are in accord with available ex
periments. (C) 1998 Elsevier Science Ltd. All rights reserved.