Photoswitchable Adhesives Using Azobenzene-Containing Materials.

Area of Science:

• Materials Science
• Polymer Science
• Supramolecular Chemistry

Background:

• Azobenzene-containing materials exhibit photoinduced reversible solid-to-liquid transitions.
• These transitions are driven by trans-cis isomerization upon light exposure.
• The distinct adhesive properties of the solid (trans) and liquid (cis) states are key.

Purpose of the Study:

• To review adhesives based on azobenzene-containing small molecules and polymers.
• To highlight the mechanism of photo-controlled adhesion.
• To discuss current challenges and future perspectives in this field.

Main Methods:

• Investigating azobenzene-containing small molecules and polymers.
• Utilizing photoswitching to induce trans-cis isomerization.
• Characterizing solid-to-liquid transitions and their impact on adhesion.

Main Results:

• Azobenzene materials can reversibly switch between strong adhesion (solid trans) and weak adhesion (liquid cis).
• Melting points/glass transition temperatures are modulated by the azobenzene isomer state.
• Photoswitching enables tunable adhesion control.

Conclusions:

• Azobenzene-based photoswitchable adhesives offer a promising platform for tunable adhesion.
• Further research is needed to address current challenges and unlock full potential.
• This review provides insights into small molecule and polymer-based systems.