Scalable and lightweight MXene-Ni-PDMS/melamine sponge with super-elastic, hydrophobic and enhanced electromagnetic interference shielding performance

The intensification of electromagnetic pollution has boosted the exploration of high-performance electromagnetic interference (EMI) shielding materials. Herein, 2D MXene, 1D nickel (Ni) chain and PDMS were anchored on 3D porous skeleton of melamine sponge (MS) by a simple, inexpensive and scalable “dipping and coating” method, and a lightweight 3D hybrid nanostructure (MXene-Ni-PDMS/MS) was prepared. Super hydrophobic, high electric conductivity, excellent EMI shielding and outstanding super-elastic performances were obtained via the synergy effect of conductive 2D MXene and 1D Ni chain and hydrophobic PDMS. The results showed that the EMI of MXene-Ni-PDMS/MS with thickness of 10 mm could reach about 50 dB, which was 50 % higher than 25 dB of sponge with thickness of 2 mm, and could meet 20 dB commercial application. Moreover, the hybrid sponge exhibited super-elastic characteristics and could recover to its original state under 60 % strain during compressive fatigue. Even when it was subjected to 500 cycles at 40 % strain, the maximum compressive stress, Young's modulus and energy loss coefficient slightly decreased, indicating that the structure could maintain stable physical properties. The water contact angle could reach 145.1°, showing hydrophobic characteristics. This work offers a novel way for synthesis of excellent EMI shielding materials based on sponge.