Development of Carbon Nanotubes–Graphene–Polydimethylsiloxane Composite Film with Excellent Electrothermal Performance

Low power density and low heating rate are the key constraints for the development of conductive polymer materials in the field of electric heating. The carbon nanotubes (CNTs)–graphene (GR)–polydimethylsiloxane (PDMS) composite film was prepared by vacuum filtration and spin coating to solve the problem in this study. Moreover, an AC electric field was used to orient the CNTs to enhance the electrothermal performance. The structure and properties of composite films were analyzed. The results show that the composite film with CNT:GR = 2:1 has the lowest permeation threshold, and can heat up within 30 s and stabilize at 260 °C at 10 V. The electric field-oriented CNTs reduced the insulating polymer layer, increasing the heating rate of the composite film by 1.2 times, and increasing the theoretical thermal conductivity. The flexible electrothermal composite film prepared in this study can be used in thermal insulation, deicing, and wearable electronic devices.