High-performance and self-healable electromagnetic interference shielding coatings based on waterborne dynamic polyurethane and Ti3C2Tx MXene composites

Developing high-performance electromagnetic interference (EMI) shielding materials that possess both mechanical resilience and self-healing capability remains a significant challenge for next-generation flexible electronics. Herein, we demonstrate a novel strategy to fabricate self-healable EMI shielding composites by integrating Ti 3 C 2 T x MXene into a dynamic, water-dispersible crosslinked polyurethane (xWPU) matrix. The polymer matrix is engineered with hindered urea bonds (HUBs) to enable reversible crosslinking and provide abundant hydrogen-bonding sites for exceptional interfacial affinity with MXene fillers. Notably, the resulting composites exhibit a low electrical percolation threshold (1.6 wt%) and superior EMI shielding effectiveness (SE) of 55.6 dB at an 8.2 wt% loading. Benefiting from the strong interfacial interactions between MXene and the polymer, the incorporation of 8.2 wt% MXene affords a simultaneous leap in overall mechanical performance, yielding increases in tensile strength by 55%, Young’s modulus by 335%. Additionally, excellent adhesion to various plastic substrates is confirmed. Thermal treatment of the damaged composites facilitates near-complete restoration of both electrical and mechanical properties. Leveraging the intrinsic photothermal effect of MXene, spatially selective self-healing of mechanical cracks is successfully achieved under near-infrared irradiation. Furthermore, the dynamic nature of the HUB network enables repeated thermal reprocessing while maintaining nearly 100% of the original mechanical properties. This work provides a robust framework for designing multifunctional, sustainable, and resilient EMI shielding materials for advanced electronic applications.