Two-dimensional (2D) layered materials have received rapidly increasing interest for a variety of applications including thermal management. Among them, graphene and hexagonal boron nitride (h-BN) are being widely investigated because of high basal plane thermal conductivity. The theoretic basal plane thermal conductivity values for clean free-standing single layer graphene can be record high because of suppression of interlayer phonon scattering. For thermal management applications, however, the 2D heat spreaders have to be in contact with a heat source and a heat sink, or embedded in a medium, and the interaction with a dissimilar material can suppress in-plane phonon transport and thermal conductivity in a 2D sheet. The suppression is even more pronounced than the inter-layer interaction between adjacent similar 2D layers in a three-dimensional stack such as graphite or bulk h-BN. Understanding the effects of interface interaction on in-plane and cross-plane phonon transport in 2D materials is thus necessary for properly evaluating the thermal management potentials of 2D materials. Besides examining this basic research question, this talk will also provide an update on on-going developments of other architectures of 2D building blocks, including nanotubes, continuous foam structures, and hybrid and composite structures, as high-performance thermal management materials. 

Two-dimensional (2D) layered materials have received rapidly increasing interest for a variety of applications including thermal management. Among them, graphene and hexagonal boron nitride (h-BN) are being widely investigated because of high basal plane thermal conductivity. The theoretic basal plane thermal conductivity values for clean free-standing single layer graphene can be record high because of suppression of interlayer phonon scattering. For thermal management applications, however, the 2D heat spreaders have to be in contact with a heat source and a heat sink, or embedded in a medium, and the interaction with a dissimilar material can suppress in-plane phonon transport and thermal conductivity in a 2D sheet. The suppression is even more pronounced than the inter-layer interaction between adjacent similar 2D layers in a three-dimensional stack such as graphite or bulk h-BN. Understanding the effects of interface interaction on in-plane and cross-plane phonon transport in 2D materials is thus necessary for properly evaluating the thermal management potentials of 2D materials. Besides examining this basic research question, this talk will also provide an update on on-going developments of other architectures of 2D building blocks, including nanotubes, continuous foam structures, and hybrid and composite structures, as high-performance thermal management materials.