Grain growth and defect annihilation in block copolymers

The time dependence of the size, shape, and concentration of ordered grains in a quenched block copolymer melt was studied by depolarized light scattering. Block copolymers are ideal systems for kinetic studies because the single scattering limit applies during all stages of grain growth. In the early stage, where the grains grow by consuming the disordered phase, grains have an elongated shape with an average aspect ratio of about 4. In the late stage, where the grains grow by defect annihilation, the grain growth occurs only along the minor axes.