High-Loading Boron Nitride-Based Bio-Inspired Paper with Plastic-like Ductility and Metal-like Thermal Conductivity

Area of Science:

• Materials Science
• Nanotechnology
• Composite Materials

Background:

• Fabricating flexible hybrid films with integrated mechanical, thermal, and electrical properties is challenging for next-generation electronics.
• Mollusk nacre utilizes a chitin nanofiber framework to host CaCO3 microplatelets, achieving high-loading composites with ductile behavior.

Purpose of the Study:

• To create a bio-inspired, boron nitride-based paper with excellent mechanical and thermal properties for flexible electronics.
• To mimic nacre's structure for high-performance composite material fabrication.

Main Methods:

• A facile sol-gel-film conversion approach was used to embed boron nitride (BN) microplatelets into a 3D poly(p-phenylene benzobisoxazole) nanofiber framework.
• The resulting BN-based paper contained 40-80 wt% BN microplatelets.

Main Results:

• The BN-based paper demonstrated plastic-like ductility (38-80%), ultrahigh toughness (10-100 MJ m⁻³), and good folding endurance due to the 3D nanofiber framework.
• An oriented, percolative network of BN platelets resulted in outstanding in-plane thermal conductivity (77.1-214.2 W m⁻¹ K⁻¹), comparable to aluminum alloys.
• The material functions as an electrically insulating flexible substrate.

Conclusions:

• The bio-inspired BN paper successfully integrates ductility, toughness, and high thermal conductivity while remaining electrically insulating.
• This material shows significant promise as a flexible substrate for thermal management in electronic devices.