In-situ growth of CuS on polyimide film to construct dense and continuous network: Achieving excellent electrothermal and EMI shielding performance

Abstract

The performance of the electrothermal film is generally determined by conductive filler network. However, it is still challenging to construct a dense network of conductive fillers in the electrothermal film. In this work, we develop a simple and efficient method to construct a dense and continuous network via in-situ growth of CuS nanosheets on the surface of polyimide (PI) film with stable interfacial bonding. The obtained PI@CuS electrothermal film is further packaged by commercially available PTFE and PI tapes to achieve desirable surface hydrophobic self-cleaning function and stability for the use in different environments. By tuning the network density of CuS nanosheets, it imparts excellent electrothermal conversion efficiency and cycling stability to the PI@CuS film, whose surface temperature could rapidly ramp up over 200 °C at 8 V. The film also exhibits excellent photothermal performance, reaching close to 100 °C at 100 mW/cm2. The anti-icing/de-icing experiment shows that the icing time is prolonged significantly at low temperature and the melting time is reduced dramatically. Furthermore, the PI@CuS film also exhibits outstanding electromagnetic interference (EMI) shielding effectiveness of 57.1 dB with a thickness of only 80 μm, and excellent tensile strength of over 90 MPa. The in-situ growth strategy provides a novel route for the fabrication of the electrothermal film with excellent overall performance.