Hierarchical Nucleophilic Nanofibrous Membranes for Fast, Durable, and Bare‐Eye Visible Detoxification of Carcinogenic Alkylating Toxicants

Colorimetric‐warning detoxification nanofibrous membranes (CDNMs) are easily and directly fabricated from electrospinning of a mixture of poly(4‐vinylpyridine), 4‐( p ‐nitrobenzyl)pyridine, and polyacrylonitrile. They exhibit hierarchical fiber morphology, ensuring fast and efficient detoxification toward alkylating toxicants. Taking advantage of their microporous structure, high specific surface area, and strong affinity toward toxicants of the nanofibers, the CDNMs exhibit a detoxification rate independent from the initial toxicant concentration (half‐lives are less than 8 min), and excellent detoxification durability and capacity with detoxification recovery rates retained >90% after 250 times cleaning of 3467 ppm methyl iodide. More importantly, a colorimetric signal that can monitor the detoxification process and expiration of the function is reported. An accumulative color change from white to brownish yellow on the CDNMs indicates the detoxification efficiency drops to less than 50%, which serves as a warning signal for a replacement of the CDNMs in personal protective equipment products. The detoxification and color generation mechanisms are theoretically supported by Gaussian calculations. This work is expected to inspire the introduction of instrument‐free detection signals into the design and development of next‐generation of self‐decontamination and detoxification materials.