Self-Modifying Nanointerface Driving Ultrahigh Bidirectional Thermal Conductivity Boron Nitride-Based Composite...

Area of Science:

• Materials Science
• Nanotechnology
• Composite Materials

Background:

• Boron nitride (BN) is a key filler for high-power electronics due to its thermal conductivity and dielectric properties.
• Poor interfacial interaction in BN composites leads to phonon scattering and low vertical thermal conductivity.
• Developing effective thermal management solutions for electronic devices is critical.

Purpose of the Study:

• To develop a novel surface modification strategy for boron nitride fillers to improve composite thermal conductivity.
• To enhance the interfacial interaction between boron nitride and polymer matrices.
• To achieve high in-plane and through-plane thermal conductivity in composite materials.

Main Methods:

• A "self-modified nanointerface" strategy using boron nitride nanocrystals (BNNCs) was employed.
• Ice-press assembly method was used to create composite films.
• Thermal conductivity was measured and verified by theoretical calculations and CPU heat dissipation tests.

Main Results:

• A composite film with only 25 wt% BN achieved an in-plane thermal conductivity of 20.3 W m^-1 K^-1.
• The composite achieved a significantly improved through-plane thermal conductivity of 21.3 W m^-1 K^-1, more than double the previous maximum.
• The enhanced conductivity is attributed to ideal phonon spectrum matching, strong filler-matrix interaction, and a ladder-structured BN skeleton.

Conclusions:

• The "self-modified nanointerface" strategy effectively overcomes interfacial phonon scattering in BN composites.
• This approach provides a new pathway for developing high-performance thermal management materials for electronic devices.
• The study offers an innovative design principle for tailoring composite interfaces.