Large-area three-dimensional molecular ordering of a polymer brush by one-step processing

Area of Science:

• Materials Science
• Polymer Chemistry
• Organic Electronics

Background:

• Rational molecular design and processing are crucial for high-performance organic materials.
• Achieving large-area molecular ordering is a key challenge in the field.

Purpose of the Study:

• To develop a method for self-assembling polymer brushes into freestanding films with controlled molecular order.
• To investigate the photoresponsive properties of the resulting ordered polymer films.

Main Methods:

• One-step hot-pressing of a polymer brush with azobenzene-containing mesogenic side chains using uniaxially stretched Teflon sheets.
• Utilizing the anisotropic molecular order of the Teflon sheet to induce macroscopic alignment in the polymer film.

Main Results:

• A freestanding polymer film with homeotropic polymer backbone alignment and horizontal side chain alignment was successfully fabricated.
• The ordered structure propagated macroscopically from the Teflon interface.
• The resulting bimorph configuration exhibited rapid and reversible bending upon photoisomerization of azobenzene units.

Conclusions:

• The combination of polymer brushes, hot-pressing, and Teflon sheets is an effective strategy for creating large-area ordered soft materials.
• This approach offers significant potential for designing novel functional soft materials with photoresponsive capabilities.