Fabrication of Hierarchical Assemblies through Temperature-Triggered Liquid Crystallization Driven Self-Assembly

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Biological systems exhibit functional hierarchy due to evolution.
• Replicating hierarchical structures in artificial materials is a key goal in materials science.
• Fabricating hierarchical structures using AB-type block copolymers (BCPs) remains challenging.

Purpose of the Study:

• To develop a simple and efficient method for creating hierarchical structures using AB-type BCPs.
• To explore the use of amphiphilic BCPs with specific functionalities for hierarchical assembly.
• To demonstrate a novel approach for constructing stable hierarchical micellar structures.

Main Methods:

• Synthesis of amphiphilic BCPs (PDenm-b-PAChonn) with dendronized oligoethylene glycol (Den) and cholesterol (AChol) moieties.
• Utilizing the temperature-induced collapse of PDen blocks for self-assembly.
• Leveraging the liquid crystalline (LC) properties of the core-forming block for stable cross-linking and guided assembly.

Main Results:

• Achieved fabrication of bundled fibers and multilayer vesicles with clear hierarchy.
• Demonstrated robust physical cross-linking via LC ordering, preventing reversible aggregation.
• Showcased epitaxial growth and lateral fusion of LC blocks for stable hierarchical structures.

Conclusions:

• The combination of temperature-sensitivity and LC ordering provides a novel strategy for hierarchical structure formation.
• This one-step assembly method offers an efficient route to complex hierarchical materials using AB-type BCPs.
• The developed method paves the way for advanced functional materials with hierarchical architectures.