Anisotropy of lamellar block copolymer grains

The Wulff construction and the theory of Milner and Morse [Phys. Rev. E 54, 3793 (1996)] were used to calculate the shape of grains formed when a lamellar block copolymer phase is formed by a shallow quench into the ordered state. The calculations show that the grains are ellipsoids of revolution, with an aspect ratio rho=2.37. This value is in reasonable agreement with results of transmission electron microscopy and depolarized light scattering experiments, which indicate that the average value of rho of grains formed during the early stages of the disorder-to-order transition is about 2.0.