Tea polyphenol-modified MWCNTs/PEDOT:PSS flexible films with “brick-mortar” structure for electrical heating and electromagnetic interference shielding

The composite films with superior electrical heating and EMI shielding performance were obtained by a facile and novel method. • The composite film achieved superior electrothermal response under the voltage of as low as 6   V, and maintained stable performance after multiple cyclic tests. • The film attained an EMI shielding effectiveness of 24   dB, and reflection palyed an important role. • The performances were in good accordance with the COMSOL simulation results, further enabling the reliability. • The superior properties of material enabled it as a promising a material for wearable thermal management and electronic device electromagnetic compatibility fields. Flexible multifunctional composites show great potential in emerging wearable electronics. Nevertheless, most reported materials have several limitations, including high filler loading, intricate fabrication process and poor functional synergy, which cannot satisfy the requirements of stable electrothermal performance and electromagnetic protection for wearable devices. Therefore, this study proposed a “brick-mortar” structure to improve the carbon nanotube dispersion, and constructed continuous conductive pathways, achieving synchronous electrothermal and electromagnetic interference (EMI) shielding performance. Accordingly, tea polyphenol-modified multi-walled carbon nanotubes (T-MWCNTs)/poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS)/polyvinyl alcohol (PVA) composite films (TPFs) were prepared via layer-by-layer deposition. The “brick” network was formed by T-MWCNTs and PEDOT:PSS provided continuous conductive paths, while PVA as the “mortar” enhanced the flexibility and interfacial adhesion. The composite film exhibited a rapid electrothermal response under 6   V, reaching to 123 °C within 90   s with superior cycling stability. It also showed an EMI shielding effectiveness of 24   dB, and reflection played an important role. These results were verified by COMSOL simulation as well. TPFs shows promising potential in wearable thermal management and electromagnetic compatibility. Download: Download high-res image (151KB) Download: Download full-size image