Smart Self-Puffing Phosphite-Protonated Siloxane Network Enables Multifunctional Transparent Protection

Harsh-condition protective materials are essential for resisting various types of environmental damage, such as fire, microbes, scratches, and etc. However, integrating multiple protective functions in one transparent flexible material without sacrificing each other remains a formidable challenge. Here, we demonstrate a smart-puffing transparent flexible phosphite-protonated siloxane (PSiP) that simultaneously exhibits excellent fire protection, high-temperature insulation, antibacterial, antimold, and self-healing properties. A facile one-step method is developed to create this microporous PSiP using (3-aminopropyl)triethoxysilane and phosphite via hydrophilic–hydrophobic interaction-driven self-assembly. Notably, PSiP employs an intelligent thermal-responsive self-puffing behavior to achieve high-temperature insulation, effectively blocking 87.8% of 1400 °C heat. The unique dynamic phosphite-protonated siloxane network in PSiP with high transparency (>92% in the visible region) affords self-healing ability as well as potent defense against fire and bacteria (>99% efficiency). Our findings open up a new avenue for developing transparent, flexible, and high-performance multihazard protective materials with potential applications in buildings, windshields, electronics, and beyond.