Highly Flexible Dielectric Films from Solution Processable Covalent Organic Frameworks

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Covalent organic frameworks (COFs) show promise for diverse applications.
• Poor solution processability of COFs currently limits their widespread use.
• Developing processable COFs is crucial for advancing materials applications.

Purpose of the Study:

• To engineer covalent organic frameworks (COFs) for improved solution processability.
• To create flexible, crystalline COF films using hydrophilic side chains.
• To evaluate the mechanical and dielectric properties of modified COFs.

Main Methods:

• Pore engineering of hydrazone- and β-ketoenamine-linked COFs using hydrophilic side chains.
• Fabrication of free-standing COF films (COF-PEO-3 and TFP-PEO-3).
• Mechanical characterization (Young's modulus) and dielectric property assessment.

Main Results:

• Successfully improved the processability and solubility of COFs.
• Produced flexible, crystalline COF films with Young's moduli of 391.7 MPa (COF-PEO-3) and 1034.7 MPa (TFP-PEO-3).
• Demonstrated high dielectric constant and breakdown strength in TFP-PEO-3 film-based capacitors, achieving 11.22 J cm⁻³ discharged energy density.

Conclusions:

• A general method for producing solution-processable COFs and flexible films has been established.
• The engineered COFs exhibit excellent mechanical properties and suitability for dielectric devices.
• These advancements hold significant potential for flexible electronics and energy storage applications.