BN-coated graphene aerogel composite spreads heat and shields EMI

Flexible and wearable electronics generate localized heat that must be spread quickly without compromising mechanical stability or electromagnetic performance. A new study reports a flexible multifunctional heat spreader built from a reduced graphene oxide aerogel-based composite structure that addresses all three demands at once.

The design starts with a reduced graphene oxide aerogel, which serves as a continuous electrically conductive framework for electromagnetic interference (EMI) shielding. Because such aerogels are fragile, the researchers added a thermoplastic polyurethane and boron nitride coating layer on the aerogel surface. Crucially, the coating was formed without fully blocking the internal pores, preserving the open pore network of the framework.

Those open pores were then filled with a hybrid filler composed of polydopamine-treated boron nitride and reduced graphene oxide aerogel flakes. Within this hybrid filler, the reduced graphene oxide aerogel flakes provided additional electrically conductive networks that contribute to EMI shielding, while the polydopamine-treated boron nitride supplied thermally conductive filler components for heat spreading.

The polydopamine layer played a supporting role in the composite’s internal architecture: it improved the contact between boron nitride and the reduced graphene oxide-based components, which supported the formation of a connected filler network throughout the material.

After hot pressing, the optimized composite exhibited an in-plane thermal conductivity of 7.35 W m⁻¹ K⁻¹ and a through-plane thermal conductivity of 1.28 W m⁻¹ K⁻¹.

The composite also achieved an EMI shielding effectiveness of 41.2 dB in the X-band range. Shielding at this level means the material attenuates the vast majority of incident electromagnetic radiation, a performance supported by the continuous conductive aerogel framework and the additional conductive networks formed by the pore-filling graphene flakes.

Mechanically, the material reached a tensile strength of 17.5 MPa. This combination of mechanical robustness with thermal and electromagnetic functionality is what makes the structure suitable for flexible devices, where materials must bend and flex while continuing to manage heat and interference.

According to the study, these results show that the combined aerogel framework, coating layer, and pore-filling hybrid filler structure is effective for flexible heat spreaders requiring heat dissipation, EMI shielding, and mechanical stability. The work was published as an open access research article in Advanced Composites and Hybrid Materials, with the shared version noted as subject to further edits before the final Version of Record.

Subject of Research: A flexible reduced graphene oxide aerogel composite with boron nitride coatings for heat spreading and electromagnetic interference shielding

Article Title: Pore-preserving BN-coated rGO composites for heat spreading and EMI shielding

Article References: Yoo, D., Kim, S., Kim, J., Yoon, S., Yang, H., Lee, J., & Kim, J. (2026). Pore-preserving BN-coated rGO composites for heat spreading and EMI shielding. Advanced Composites and Hybrid Materials. https://doi.org/10.1007/s42114-026-02139-1

Image Credits: AI Generated

DOI: 10.1007/s42114-026-02139-1

Keywords: thermal management, graphene aerogel, boron nitride, EMI shielding, flexible electronics, heat spreader, polydopamine, thermoplastic polyurethane, hot pressing, wearable electronics, Pore-preserving, BN-coated