Experimental and analytical studies on the flexible, low-voltage electrothermal film based on the multi-walled carbon nanotube/polymer nanocomposite.

This paper presents multi-walled carbon nanotube (MWCNT)/poly(m-phenylene isophthalamide) (PMIA) nanocomposite films as electrothermal elements, which offer advantages in flexibility, low energy consumption and rapid temperature growth. The electrical properties, electrothermal behavior and thermal stability of the films were investigated as a function of MWCNT content. The percolation behavior analysis revealed MWCNTs built a continuously conductive network in PMIA matrix at the corresponding percolation threshold of ~0.06 wt%. The electrothermal behavior of the MWCNT/PMIA film was investigated by considering temperature response rapidity and electrothermal efficiency under different ambient conditions. For the film with 7.0 wt% MWCNTs under different ambient conditions, the film worked at a high heating rate of 1.0-8.2 °C/s and cooling rate of 0.75-7.0 °C/s under a low voltage of 3-12 V, due to the low electrical resistivity (4.5 Ω∙cm) of the film. The prepared MWCNT/PMIA films supported more outstanding heating performance than conventional PI-Kanthal film, including good heating uniformity, higher electrothermal efficiency and heating/cooling rate. Moreover, the improved thermomechanical properties of the nanocomposite were observed by dynamic thermomechanical analysis (DMA).