Flexible rubber-based nanocomposite with superior electromagnetic interference shielding and joule heating

Flexible multifunctional electromagnetic interference (EMI) shields that integrate effective electromagnetic wave (EMW) absorption, and efficient Joule heating are highly sought after for advanced electronic applications. In this study, we developed a robust, flexible, and multifunctional multi-layered gradient system using a two-step fabrication process, which includes compound solution mixing followed by hot press molding. The system consists of alternating magnetic layers (carbonized metal-organic framework (CMOF)/styrene butadiene rubber (SBR)) and conductive layers (carbon nanotube (CNT)/SBR). The resulting CNT-reinforced gradient nanocomposite exhibits impressive mechanical properties, with an elongation at break reaching up to 120% and ultimate stress up to 13 MPa. Leveraging an absorption-reflection-reabsorption mechanism, the multi-layered gradient nanocomposite achieved an absorption rate of up to 57% and an EMI shielding effectiveness (EMI SE) of 50 dB at a thickness of just 1 mm. Notably, the flexible structure maintains its performance after 500 cycles of bending and twisting, with only minimal reduction in EMI SE, retaining values of 47 dB and 46 dB, respectively. Furthermore, the composite demonstrates efficient electro-thermal conversion, achieving a steady-state temperature of 152 °C under a driving voltage of 10V. In short, this study presents an innovative approach to designing absorption-dominant, high-performance EMI shielding structures that combine mechanical robustness, and Joule heating capabilities, positioning it as a promising candidate for next-generation advanced electronic devices and energy conversion systems. • Fabricated flexible multifunctional EMI shields with a layered gradient design. • Achieved 57% EMW absorption and 50 dB EMI shielding at a thickness of 1 mm. • Gradient nanocomposite exhibited 120% elongation and tensile strength of 13 MPa. • Retained EMI shielding performance (46-47 dB) after 500 bending and twisting cycles. • Demonstrated efficient Joule heating, reaching 152°C under a 10V applied voltage.