Scalable Approach to Construct Self-Assembled Graphene-Based Films with An Ordered Structure for Thermal Management

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Science

Background:

• Developing high-performance thermal management materials is crucial for advanced electronics and energy systems.
• Graphene and cellulose nanocrystals offer unique properties for composite materials.
• Achieving efficient thermal transport in bulk composites remains a challenge.

Purpose of the Study:

• To develop a cost-effective, large-scale method for producing oriented oxidized cellulose nanocrystal/graphene nanocomposites.
• To investigate the thermal transport properties of these novel nanocomposites.
• To establish a new design strategy for large-area aligned functional composites.

Main Methods:

• Evaporation-induced self-assembly of oxidized cellulose nanocrystal and graphene.
• Thermal curing of the self-assembled structures.
• Characterization of structural alignment and thermal conductivity.

Main Results:

• Successfully produced large-area bulk oxidized cellulose nanocrystal/graphene nanocomposites with highly oriented structures.
• Demonstrated well-aligned graphene layers separated by oxidized cellulose nanocrystal layers.
• Achieved an excellent in-plane thermal conductivity of 25.66 W/m K with only 4.1 vol % graphene loading.
• Reported a thermal conductivity enhancement of 7235%, the highest for laminated composites with <70 wt % filler.

Conclusions:

• The straightforward, scalable evaporation-induced self-assembly and thermal curing process is effective for creating high-performance thermal conductive nanocomposites.
• The oriented structure facilitates highly efficient in-plane thermal transport.
• This strategy enables the development of other large-area aligned composites for diverse applications.