Preparation and infrared shielding of polyaniline@MWCNTs flexible electrochromic device based on cotton fabric

Electrochromic fabric was formed by interfacial polymerization of polyaniline (PANI) and multi-walled carbon nanotubes (MWCNTs) on the surface of cotton cloth. The morphology and properties of the composite films were controlled by changing the content of multi-walled carbon nanotubes. The electrochromic properties of the fabric and its application in the field of near-infrared thermal shielding were studied. It is found that the electrochromic fabrics with MWCNTs have better electrochemical and color-changing properties. Electrochromic fabrics achieve color changes from light yellow to yellow-green to dark green in the voltage range of −1.0–1.2 V, and maintain a fast color switching time (2.15 s for coloring, 1.89 s for bleaching) after 600 cycles. The reflection contrast (ΔR) at 500 nm is 23.01 %. Moreover, the electrochromic devices are assembled with fabrics. The device has obvious discoloration and good bending stability. In addition, the thermal shielding is realized by using their reflection characteristics in the visual-near-infrared region. The results show that the electrochromic device has a low surface temperature at different environmental condition, and the thermal reduction from the original state to the bleached state is up to 3.8 ° C, indicating the potential application of the device in thermal regulation.