Graphene-multilayer graphene nanocomposites as highly efficient thermal interface materials

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Science

Background:

• Effective thermal management is critical for electronic devices.
• Conventional thermal interface materials (TIMs) often face limitations in thermal conductivity and mechanical properties.
• Graphene and its derivatives offer promising properties for advanced TIMs.

Purpose of the Study:

• To develop a high-performance thermal interface material using graphene and multilayer graphene.
• To investigate the enhancement of cross-plane thermal conductivity in graphene-polymer composites.
• To evaluate the potential of graphene-based nanocomposites as superior alternatives to existing TIMs.

Main Methods:

• High-yield, inexpensive liquid-phase exfoliation technique for producing graphene and multilayer graphene mixtures.
• Laser flash measurements to determine the cross-plane thermal conductivity (K) of the composites.
• Modeling to compare the performance of graphene-multilayer graphene nanocomposites with other filler materials.

Main Results:

• A record-high enhancement of K by 2300% was achieved in a graphene-based polymer composite at 10 vol % filler loading.
• The presence of single-layer and bilayer graphene flakes alongside larger multilayer graphene was essential for the observed enhancement.
• Commercial thermal grease conductivity increased from 5.8 W/mK to 14 W/mK with only 2% loading of the hybrid material, preserving mechanical properties.

Conclusions:

• Optimized graphene-multilayer graphene mixtures significantly enhance the thermal conductivity of polymer composites.
• The developed nanocomposite demonstrates superior performance as a thermal interface material compared to those using carbon nanotubes or metal nanoparticles.
• The liquid-phase exfoliation method provides a cost-effective route to high-performance graphene-based thermal management solutions.