Highly Thermally Conductive Boron Nitride Fiber.

Area of Science:

• Materials Science
• Nanotechnology
• Thermal Engineering

Background:

• Advanced fiber materials are crucial for thermal management in electronics and aerospace.
• Boron nitride (BN) fibers offer high thermal conductivity and electrical insulation, but research on pure, one-dimensional forms is limited.
• Existing studies often focus on BN nanosheets in polymer composites, not pure BN fibers.

Purpose of the Study:

• To fabricate continuous, pure boron nitride (BN) fibers using a polymer-derived ceramic method.
• To investigate the thermal conductivity of single BN fibers.
• To evaluate the performance of BN fiber-reinforced composites as thermal interface materials.

Main Methods:

• Fabrication of pure BN fibers via the polymer-derived ceramic approach.
• Structural characterization to confirm fiber quality and purity.
• Measurement of single BN fiber thermal conductivity using a developed big-MEMS method.
• Preparation of vertically aligned BN fiber-reinforced epoxy composites using a stacking-cutting method.

Main Results:

• Successfully fabricated high-quality, pure continuous BN fibers.
• Precisely measured the thermal conductivity of a single BN fiber at 54 W m^-1 K^-1.
• Achieved a thermal conductivity of 24 W m^-1 K^-1 in BN fiber-reinforced epoxy composites.

Conclusions:

• Pure BN fibers are a viable material for thermal management applications.
• The developed fabrication and characterization methods enable precise evaluation of BN fiber properties.
• BN fiber composites demonstrate significant potential as effective thermal interface materials, especially where electrical insulation is required.