Green and scalable processing aramid nanofiber and mica into a bioinspired fire-resistant insulation paper

Despite the excellent fire resistance and electrical insulation properties of mica, its intrinsic brittleness and limited processability restrict its application in processable and high-performance insulating materials. In this work, a bioinspired “brick-and-mortar” strategy was used to fabricate high-mica-content aramid nanofiber/mica (A-M) composite papers through a scalable papermaking process. In this architecture, rigid mica platelets are incorporated into a continuous ANF network to form a layered structure, where the low-content ANF phase may bridge adjacent mica platelets and improve the interfacial compatibility between the organic and inorganic components. Only 3–10 wt% ANFs were introduced as a binding and reinforcing network, while a mica-dominated inorganic framework was largely preserved. The 10 wt% A-M paper exhibited a tensile strength of 32.98 MPa and a breakdown strength of 24.92 kV mm −1 , together with good flame-retardant behavior and insulation stability. Importantly, the fabrication approach supports continuous, large-area paper production, highlighting its scalability and promising potential for electrical insulation applications. Multiple A-M paper sheets can be self-bonded into an insulating laminate via hot pressing, leading to simultaneous enhancements in mechanical strength and thermal stability. This work provides a general strategy for the design of high-performance, processable, and fire-resistant electrical insulation materials.