Preparation and characterization of novel core-shell microcapsules containing C₆F₁₂O for initial fire suppression

As an environmentally friendly and efficient fire extinguishing agent, C₆F₁₂O (CFO) is widely used for various types of fires. However, due to its low vaporization temperature and high vapor pressure, it is difficult to store and utilize. In order to reduce the loss and improve fire suppression efficiency of CFO, the complex coacervation method was employed to encapsulate CFO using a polymer material shell composed of gelatin (GE) and arabic gum (GA). The experimental results demonstrated that the preparation parameters had a significant impact on the microcapsule encapsulation efficiency. When the coacervation temperature was set to 40°C, the coacervation pH value was maintained at 3.8, the shell material concentration was adjusted to 8 %, and the core-shell mass ratio was kept at 4:1, the microcapsule encapsulation efficiency reached its peak at 26.4 %. CFO was successfully encapsulated as confirmed by characterization techniques such as TG, FT-IR, SEM, and ¹⁹F NMR. CFO was released by breaking through the shell when the microcapsules reached the thermal response temperature. Additionally, the fire suppression tests showed that the microcapsules exhibited highly efficient fire extinguishing performance. They decreased the maximum temperature of the n-heptane flame by 196.7°C, lowered the temperature rate by 4.07 °C/s, and shortened the self-extinguishing time by 47 s. These results provide a new and effective solution for the microencapsulation of heat-sensitive materials and early-stage fire suppression.