Direct-ink-write cross-linkable bottlebrush block copolymers for on-the-fly control of structural color

Area of Science:

• Materials Science
• Nanotechnology
• Additive Manufacturing

Background:

• Controlling nanoscopic structures during additive manufacturing is difficult.
• Self-assembly offers a route to creating ordered nanostructures.
• Dynamic modulation of these structures remains a significant challenge.

Purpose of the Study:

• To develop a UV-assisted direct ink write method for on-the-fly modulation of structural color.
• To program the assembly kinetics of bottlebrush block copolymers through photo-cross-linking.
• To achieve spatiotemporal control over self-assembled nanostructures during 3D printing.

Main Methods:

• Designing a photo-cross-linkable bottlebrush block copolymer ink.
• Utilizing UV-assisted direct ink write additive manufacturing.
• Employing coarse-grained simulations, rheological measurements, and structural characterizations.
• Modulating UV-light irradiance during printing to control assembly kinetics.

Main Results:

• Vibrant structural color was achieved due to nanoscopic lamellar structures formed post-extrusion.
• A broad spectrum of visible light colors and gradients were accessible with a single ink.
• The mechanism involves matching cross-linking and assembly timescales for kinetic trapping.
• Structural color evolved from blue to red, driven by solvent evaporation.

Conclusions:

• The developed UV-assisted approach enables dynamic control over structural color in 3D printed materials.
• Integrating cross-linking chemistry with out-of-equilibrium processing allows precise spatiotemporal control of nanostructures.
• This strategy opens new possibilities for advanced functional materials with tunable photonic properties.