A bio-inspired, cross-scale, hierarchical MXene flame retardant nanocoating for reliable, ultrafast, ultralong fire warning

Abstract

Ti₃C₂T_x MXene/polymer composites demonstrate a massive potential for multifunctional applications in various fields, particularly for fire safety enhancement. Unfortunately, designing MXene/polymer composites with a balanced combination of mechanical robustness, high-temperature resistance, high flame responsivity, rapid-fire response, and ultralong alarm duration remains challenging. Herein, a bio-inspired, cross-scale, hierarchical design was employed to fabricate an intelligent MXene-based nanocoating (PMS) through the evaporation-induced self-assembly of molecular polyvinyl alcohol, nanometer-scale polydopamine coated silica, and nanometer-to-micron-scale MXene. This design leverages a bioinspired interaction network, which enhances both strength and toughness, improving the tensile strength and Young's modulus by 210% and 72%, respectively, compared to unoptimized systems. Furthermore, the incorporation of ceramic fusion-assisted carbonization within the MXene-based bionic network endows PMS with exceptional flame retardancy (VTM-0), high flame responsiveness (>10⁵), ultrafast fire alarm response (∼0.85 s), and ultralong alarm duration time (>2930 s). These attributes position PMS as an advanced FAS material with intrinsic fire safety and active fire-fighting performance. This work provides an innovative strategy for designing MXene-based smart materials and advancing high-performance fire warning technologies.