Priming self-assembly pathways by stacking block copolymers

Area of Science:

• Polymer Science
• Materials Science
• Nanotechnology

Background:

• Block copolymers self-assemble into nanoscale structures.
• Equilibrium assembly yields limited structural diversity.
• Non-equilibrium strategies offer potential for expanded morphologies.

Purpose of the Study:

• To develop a novel non-equilibrium strategy for block copolymer self-assembly.
• To explore the vast processing and material parameter space for novel structure formation.
• To create exotic, non-native nanostructures surpassing equilibrium limitations.

Main Methods:

• Pathway priming strategy combining controlled initial configurations and ordering history.
• Sequential coating of distinct materials to create prescribed non-equilibrium initial states.
• Thermal annealing to guide evolution through the assembly landscape.

Main Results:

• Demonstrated a library of exotic non-native morphologies.
• Achieved vertically-oriented perforated lamellae, aqueduct structures, parapets, and crisscrossing lamellae networks.
• Explored the hyperspace of processing, material, and layering dimensions.

Conclusions:

• Enhanced structural control in block copolymer self-assembly is achievable through non-equilibrium pathway priming.
• Novel morphologies with potentially superior functional properties can be accessed.
• This strategy expands the accessible structural diversity beyond equilibrium constraints.