Abstract A series of perfluoro-2,5-dimethyl-3,6-dioxanonanoic acid ester fluorocarbon surfactants, CF 3 CF 2 CF 2 OCF(CF 3 )CF 2 OCF(CF 3 )COOC n H 2 n +1 (C 9 F 17 O 4 –C n H 2 n +1 : n = 8, 12, 16, 18), were synthesized by esterification of 2,3,3,3-tetrafluoro-2-(1,1,2,3,3,3-hexafluoro-2-(heptafluoropropyloxy)-propoxy)-propionic acid fluoride with 1-octanol, 1-dodecanol, 1-hexadecanol and 1-octadecanol, respectively. The structures of C 9 F 17 O 4 –C n H 2 n +1 ( n = 8, 12, 16, 18) were extensively characterized by FT-IR, 1 H NMR and 19 F NMR. The results of study on the surface activities show they have low surface tension and can significantly reduce the surface tensions of organic solvents by 40–83%. Besides, the critical micelle concentrations of these surfactants in solvents with different polarities have been identified at 18 °C. Furthermore, the surface excess concentrations and the effective cross-section areas of C 9 F 17 O 4 –C n H 2 n +1 in cyclohexane have been analyzed in detail. The arrangements of these surfactants at the air/solvent interface were speculated thereby.

中文翻译：

---

全氟-2,5-二甲基-3,6-二氧壬酸酯氟碳表面活性剂的合成及表面活性

摘要 一系列全氟-2,5-二甲基-3,6-二氧杂壬酸酯氟碳表面活性剂，CF 3 CF 2 CF 2 OCF(CF 3 )CF 2 OCF(CF 3 )COOC n H 2 n +1 (C 9 F 17 O 4 –C n H 2 n +1 : n = 8, 12, 16, 18)，由 2,3,3,3-四氟-2-(1,1,2,3, 3,3-六氟-2-(七氟丙氧基)-丙氧基)-丙酰氟分别与1-辛醇、1-十二烷醇、1-十六烷醇和1-十八烷醇。C 9 F 17 O 4 –C n H 2 n +1 ( n = 8, 12, 16, 18) 的结构通过FT-IR、1 H NMR和19 F NMR进行了广泛表征。表面活性研究结果表明，它们具有低表面张力，可以显着降低有机溶剂的表面张力40-83%。此外，这些表面活性剂在不同极性溶剂中的临界胶束浓度已在 18 °C 下确定。此外，详细分析了C 9 F 17 O 4 –C n H 2 n +1 在环己烷中的表面过量浓度和有效横截面积。由此推测这些表面活性剂在空气/溶剂界面处的排列。