Epitaxial Transition from Gyroid to Cylinder in a Diblock Copolymer Melt

Abstract

An epitaxial transition from a bicontinious double gyroid to a hexagonally packed cylinder structure induced by an external flow is simulated using real-space dynamical self-consistent field technique. In order to simulate the structural change correctly, we introduce a system size optimization technique by which emergence of artificial intermediate structures are suppressed. When a shear flow in [111] direction of the gyroid unit cell is imposed, a nucleation and growth of the cylinder domains is observed. We confirm that the generated cylindrical domains grow epitaxially to the original gyroid domains as gyroid $d_{\{220\}}$ $\to$ cylinder $d_{\{10\}}$. In a steady state under the shear flow, the gyroid shows different reconnection processes depending on the direction of the velocity gradient of the shear flow. A kinetic pathway previously predicted using the self-consistent field theory where three fold junctions transform into five fold junctions as an intermediate state is not observed.

arXiv comment24 pages, 14 figures, submitted to Macromolecules

References in corpus (1)

• Dynamic Self-Consistent Field Theory for Unentangled Homopolymer Fluids

Cited by in corpus (2)

• Hybrid Dynamic Density Functional Theory for Polymer Melts and Blends
• Transition pathways in Cylinder-Gyroid interface