Enhancing safety in small confined spaces with thermally triggered fire-extinguishing microcapsules from microfluidics.

Fires in small confined spaces have problems such as difficulty extinguishing, fast burning speed, long duration, strong concealment, and untimely warning. Perfluorohexanone-based fire-extinguishing microcapsule technology provides an important solution to overcome these problems. However, due to the poor solubility and high volatility of perfluorohexanone, the preparation of perfluorohexanone fire-extinguishing microcapsules (FEMs) with a high encapsulation rate, good homogeneity, and low processing costs is still a great challenge. Here, we propose a microfluidic flow-focusing technique to realize efficient encapsulation of perfluorohexanone. It is shown that FEMs can spray fire-extinguishing agents at high speeds in the presence of external heat, and only one FEM is needed to extinguish a candle flame much larger than its size. Meanwhile, the extension of FEMs to two-dimensional fire-extinguishing patches (FEPs) has achieved significant results in suppressing fire and preventing fire spread, which is expected to further expand its application in various fire suppression scenarios.