New Material: Highly Anisotropic Thermal Conductive Graphene Composites To Achieve Photoelectric And Electrothermal Synergistic Ice Control

According to the design idea of "3D printing structure design - laser interface engineering - cross scale performance control", Wang Zhenyang team from the Institute of Solid State Physics, Hefei Institute of Material Science, Chinese Academy of Sciences has developed a graphene/polymer composite double-layer structure with high anisotropic thermal conductivity, high photo thermal/electrothermal conversion efficiency and good hydrophobic and mechanical properties.

In order to take advantage of the anisotropic thermal conductivity of graphene sheets, a dual nozzle melting deposition molding 3D printing technology was used to realize the directional arrangement of graphene. A double-layer structure composed of graphene reinforced thermoplastic polyurethane and pure thermoplastic polyurethane was designed, and the directional thermal conductivity and thermal storage effects of the double-layer structure of graphene reinforced thermoplastic polyurethane were evaluated. It is found that larger graphene enhances in-plane thermal conductivity due to the continuous thermal conduction path formed. The thermal conductivity of the upper graphene reinforced thermoplastic polyurethane composite in the IP direction is 4.54 W/(m·K)， It is about 6 times the thermal conductivity in the TP direction. At the same time, the pure thermoplastic polyurethane bottom layer further improves this performance, making the graphene reinforced thermoplastic polyurethane double-layer structure present an anisotropic thermal conductivity ratio of about 8.

In order to improve the anisotropic thermal conductivity of composites, the graphene reinforced thermoplastic polyurethane bilayer structure with 3D printing by laser induced treatment was studied. It is found that laser treatment preserves the orientation of graphene sheets and the integrity of the double-layer structure in the composite, exposes and reconstructs graphene networks, forms a reinforced thermoplastic polyurethane carbonization layer, regulates its defect state, and improves anisotropic conductivity and anisotropic heat conduction ratio. After laser treatment decomposes the polymer matrix, the micro scale structure and rough surface formed on the composite surface improve the surface hydrophobicity of the material, make the incident light reflect multiple times to extend the optical path, and enhance the photothermal conversion efficiency.

This work, combined with finite element analysis and molecular dynamics simulation, has studied and optimized the printing model of melting deposition molding and the process of laser processing and decomposition of polymer, which is expected to provide new solutions for applications such as deicing and anti icing of aircraft wing surfaces and building exterior wall antenna photovoltaic panels.

Relevant research results were published in Carbon and Chemical Engineering Journal). The research work was supported by the National Key R&D Program and the National Natural Science Foundation of China.