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Defects in Lamellar Diblock Copolymers: Chevron- and Omega-shaped Tilt Boundaries

Yoav Tsori·David Andelman·Michael Schick
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Abstract

We investigate symmetric grain boundaries in a lamellar diblock copolymer system. The form of the interface between two grains strongly depends on the angle $θ$, between the normals of the grains. When this angle is small, the lamellae transform smoothly from one orientation to the other, creating the chevron morphology. As $θ$ increases, a gradual transition is observed to an omega morphology characterized by a protrusion of the lamellae along the interface between the two phases. We present a theoretical approach to find these tilt boundaries in two-dimensional systems, based on a Ginzburg-Landau expansion of the free energy. Calculated order parameter profiles and energies agree well with transmission electron microscope experiments, and with full numerical solution of the same problem.

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Yoav Tsori, David Andelman, Michael Schick. 2000-08-28. Defects in Lamellar Diblock Copolymers: Chevron- and Omega-shaped Tilt Boundaries. https://doi.org/10.1103/physreve.61.2848

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