Michael Addition Inducing Self-Assembly to Construct Mechanochromic BP Film

Area of Science:

• Materials Science
• Nanotechnology
• Soft Matter Physics

Background:

• Liquid crystalline blue phases (BP) exhibit 3D cubic nanostructures, offering unique optical properties for photonic crystals.
• Challenges exist in simultaneously achieving self-assembly and mechanochromic responses in soft 3D cubic nanostructures.

Purpose of the Study:

• To present a scalable strategy for preparing soft 3D cubic nanostructured films with mechanochromic properties.
• To investigate the self-assembly and phase transitions of blue phases induced by chemical reactions.

Main Methods:

• Utilizing Michael addition reaction oligomerization to induce the assembly of double-twisted cylinders.
• Employing composite mask photopolymerization to create patterned blue phase films.
• Investigating phase transitions from Blue Phase II (BPII) to Blue Phase I (BPI) and chiral nematic phases.

Main Results:

• Achieved a scalable preparation of soft 3D cubic nanostructured films.
• Demonstrated distinct mechanochromic sensitivity in BP patterns derived from different phases.
• Reported reversible erasure and recurrence of patterns using mechanical force and temperature.
• Obtained an average domain size of 96 µm for BPII, significantly larger than conventional methods.

Conclusions:

• The developed strategy enables the creation of mechanochromic blue phase materials with controllable self-assembly.
• This work offers new insights into the selective chemochromism and self-assembly of functional materials.
• The findings pave the way for advanced functional materials and devices with tunable optical and mechanical responses.