Hierarchically structured materials from block polymer confinement within bicontinuous microemulsion-derived...

Area of Science:

• Materials Science
• Polymer Science
• Nanotechnology

Background:

• Block polymer self-assembly is crucial for creating nanostructured materials.
• Confinement effects significantly alter block polymer morphologies compared to bulk behavior.
• Previous studies focused on 2D and 3D confinement, but novel templating methods are needed.

Purpose of the Study:

• To investigate block polymer self-assembly within a novel nanoporous polyethylene template.
• To explore the creation of hierarchical structures with dual length scales.
• To develop new hierarchically structured porous monoliths using this templating approach.

Main Methods:

• Utilized nanoporous polyethylene, derived from a bicontinuous microemulsion, as a confinement template.
• Infiltrated the template with cylinder-forming block polymers: poly(isoprene-b-2-vinylpyridine), poly(styrene-b-isoprene), and poly(isoprene-b-dimethylsiloxane).
• Characterized the resulting hierarchical structures and generated porous monoliths by cross-linking and template extraction.

Main Results:

• Achieved unique hierarchical arrangements with periodicity at ~100 nm due to template confinement.
• Observed microphase-separated morphologies within the block polymer networks, similar to cylindrical pore confinement.
• Demonstrated spatially variant morphologies due to the interconnected, size-distributed nature of the polyethylene template.
• Successfully created 3D porous monoliths with pore walls retaining block polymer microphase-separated structures.

Conclusions:

• Nanoporous polyethylene serves as an effective template for creating complex, hierarchical block polymer structures.
• This method allows for the generation of novel porous materials with controlled nanoscale features.
• The resulting hierarchically structured porous monoliths hold potential for advanced applications in nanotechnology and materials science.