Sustainable electromagnetic interference shielding materials from cellulose-grafted n-type polymers

Electronic waste (e-waste) from ever-shorter device lifecycles is fueling a search for sustainable alternatives to conventional electromagnetic interference (EMI) shielding materials, which are typically non-degradable and hard to recycle. Addressing this challenge, here we present a durable, high-performance EMI shielding film that is both recyclable and biodegradable. Thanks to a simple fabrication process, our introduced composite blends renewable cellulose nanofibers, a conductive n-type polymer, and a small ionic liquid additive into a robust film. This all-organic film achieves tunable shielding effectiveness between 29.77 to 83.77 dB, comparable to traditional metal or carbon-based shields. The film demonstrates good recyclability, retaining 97.72% of its initial EMI shielding performance after ten reprocessing cycles. Furthermore, it undergoes complete biodegradation in soil at the end of its lifecycle, leaving no persistent waste, thereby offering a sustainable solution for EMI shielding applications. Combining strong EMI shielding with end-of-life degradability and reusability, this work offers a sustainable pathway to electronics that reduce e-waste and promote a circular economy.