A small amount of MXene effectively improves the thermal conductivity of the boron nitride composite film

With the high integration and miniaturization of modern electronic devices, the heat dissipation of these devices has gradually become a key factor limiting their performance development. Today, with the discovery of two-dimensional nanomaterials such as graphene, two-dimensional materials with ultra-high in-plane thermal conductivity can be used as fillers to improve thermal conductivity. However, when a two-dimensional nanomaterial is used as a thermally conductive filler, its dispersibility in the material must also be considered. In 2011, a new two-dimensional transition metal compound (MXene) was discovered for the first time. Researchers found that MXene has excellent electrical, thermal, photothermal, and energy storage properties. MXene is also a potentially ideal thermally conductive filler because of its good dispersibility in polar solvents and ease of mixing and processing.

Recently, under the guidance of Professor Wu Peiyi, a master student of Fudan University, Huang Xianwu prepared a composite film with both high in-plane thermal conductivity and electrical insulation properties. As shown in Figure 1, by adding a small amount of MXene nanosheets, the in-plane thermal conductivity of the boron nitride-based composite film can reach a maximum of 52.4 W m-1 K-1, while still maintaining the electrical insulation resistivity. The addition also greatly improved the mechanical properties of the membrane.

Figure 1 Thermal conductivity, resistivity and mechanical properties of MXene-BNNS composite film

Through scanning electron microscope observation, as shown in Figure 2, the improvement in in-plane thermal conductivity can be attributed to two aspects: 1. MXene nanosheets serve as a thermally conductive "bridge" to connect adjacent boron nitride nanosheets, filling the gap between nanosheets Voids, thereby reducing the conduction thermal resistance between the interfaces; 2. MXene surface has a wealth of negatively charged functional groups, and through electrostatic repulsion, the boron nitride nanosheets can be better dispersed in water, so MXene also improves Effect of in-plane orientation of boron nitride nanosheets.

Fig.2 FESEM and EDX spectra of MXene-BNNS composite film

This work not only expands the application of MXene, but also provides inspiration for the design of highly thermally conductive composite films.

Source-WeChat public: MCF Materials Chemistry Frontiers