Liu Yurong, Chen Ruiyu, Guo Shuanglin, Wang Zhixuan, Pan Renming
School of Safety Science and Engineering (School of Emergency Management), Nanjing University of Science and Technology, Nanjing 210094, China.
Molecules. 2024 Aug 12;29(16):3830. doi: 10.3390/molecules29163830.
Ultra-fine dry powder extinguishing agent (UDPEA) is a promising alternative to Halon agents in aviation firefighting. The formulation of UDPEAs should balance environmental friendliness and practical engineering requirements, including high extinguishing efficiency, excellent flowability, and prolonged anti-reignition. This study investigates the effects of three modification methods (single perfluorooctyl triethoxysilane (FOTS), single N-(3-Triethoxysilylpropyl)perfluoro(2,5-dimethyl-3,6-dioxanonanoyl)amide (PFPE), and a combination of FOTS and PFPE at various mass ratios (2.0:0.4, 1.6:0.8, 1.2:1.2, 0.8:1.6, 0.4:2.0) (g)) on the performance of sodium bicarbonate-based UDPEA. The results indicate that using FOTS or PFPE alone improves the water and oil contact angles, but still fails to meet the required hydrophobicity and oleophobicity standards, and it also reduces the flowability and fire-extinguishing capability. A combination of FOTS and PFPE at the 1:2 ratio yields the best performance, with the water and oil contact angles of 145.169° and 143.542°, respectively, the lowest flowability index (0.224), minimal extinguishing concentration and time (14.183 g/m and 1.976 s, respectively), which is only 52.7% and 68.3% of those of the unmodified UDPEA's (26.927 g/m and 2.893 s), and the longest anti-reignition time (68.5 s). In addition, the fire-extinguishing mechanisms (chemical inhibition and physical heat absorption) and anti-reignition mechanisms of the modified UDPEA (with the FOTS to PFPE ratio of 1:2) were revealed. This research aims to design an eco-friendly, high-performance UDPEA as an effective substitute for Halon extinguishing agents. These findings can provide valuable insights for evaluating and selecting aviation fire-extinguishing agents.
超细干粉灭火剂（UDPEA）是航空灭火中哈龙灭火剂的一种有前景的替代品。UDPEA的配方应在环境友好性和实际工程要求之间取得平衡，包括高灭火效率、优异的流动性和延长的抗复燃性。本研究考察了三种改性方法（单全氟辛基三乙氧基硅烷（FOTS）、单N-(3-三乙氧基甲硅烷基丙基)全氟(2,5-二甲基-3,6-二氧杂壬酰)酰胺（PFPE）以及FOTS和PFPE以各种质量比（2.0:0.4、1.6:0.8、1.2:1.2、0.8:1.6、0.4:2.0）（克）的组合）对碳酸氢钠基UDPEA性能的影响。结果表明，单独使用FOTS或PFPE可提高水和油的接触角，但仍未达到所需的疏水性和疏油性标准，并且还会降低流动性和灭火能力。FOTS和PFPE以1:2的比例组合产生最佳性能，水和油的接触角分别为145.169°和143.542°，最低流动指数（0.224），最小灭火浓度和时间（分别为14.183克/立方米和1.976秒），分别仅为未改性UDPEA的（26.927克/立方米和2.893秒）的52.7%和68.3%，以及最长抗复燃时间（68.5秒）。此外，还揭示了改性UDPEA（FOTS与PFPE比例为1:2）的灭火机制（化学抑制和物理吸热）和抗复燃机制。本研究旨在设计一种环保、高性能的UDPEA作为哈龙灭火剂的有效替代品。这些发现可为评估和选择航空灭火剂提供有价值的见解。
