Responsive Blends of Block Copolymers Stabilize the Hexagonally Perforated Lamellae Morphology

Citation

Nowak, S.R.; Tiwale, N.; Doerk, G.S.; Nam, C.-Y.; Black, C.T.; Yager, K.G. "Responsive Blends of Block Copolymers Stabilize the Hexagonally Perforated Lamellae Morphology" Soft Matter 2023, 19 2594–2604.
doi: 10.1039/D3SM00142C

Summary

We investigate ordering of blends of BCP cylinder and lamellar chains, showing that they form varied morphologies, including HPL. The blending of chains stabilizes such states.

Abstract

Blends of block copolymers can form phases and exhibit features distinct from the constituent materials. We study thin film blends of cylinder-forming and lamellar-forming block copolymers across a range of substrate surface energies. Blend materials are responsive to interfacial energy, allowing selection of pure or coexisting phases based on surface chemistry. Blending stabilizes certain motifs that are typically metastable, and can be used to generate pure hexagonally perforated lamellar thin films across a range of film thicknesses and surface energies. This tolerant behavior is ascribed to the ability of blend materials to redistribute chains to stabilize otherwise high-energy defect structures. The blend responsiveness allows the morphology to be spatially defined through multi-tone chemical surface patterns.