Development of Novel Fluoroalkyl End-Capped Gemini Surfactants to Emulsify Fluorinated Oil

全氟辛酸（PFOA）具有良好的表面活性剂和化学稳定性，已被广泛用作氟化油的乳化剂，但PFOA在人体内、生物体内以及环境中的残留问题已成为人们关注的焦点。因此，开发新型无残留和低残留的表面活性剂是氟化油乳化的必要条件。针对目前已知具有短氟烷基的氟化学物质在体内仅以低水平存在的特点，设计并制备了以氟烷基为端盖的新型两亲水和两亲脂表面活性剂（Gemini）。2005-2006年，以1,4-戊二烯为原料，以氟烷基自由基的加成为关键步骤，成功制备了具有多种氟烷基的SO3H型Gemini表面活性剂。2006-2007年，还建立了通过两个氟烷基取代的丙二酸酯与几个亚甲基间隔物连接生成COOH型Gemini表面活性剂的新路线。通过测量表面张力和表面压力-面积曲线，研究了它们的表面活性剂性能。与相应的方便的氟化表面活性剂相比，它们具有优异的表面张力降低能力，临界胶束浓度降低了1 ~ 2个数量级。此外，基于表面压力-面积测量，表明它们具有优越的界面吸附和排列能力，并降低了油水界面张力，这意味着它们有希望成为PFOA的替代品。接下来，进行了氟化油乳化的实际研究。

Though perfluorooctanoic acid (PFOA), which is chemically and biologically stable and has excellent surfactant properties, has been widely used as an emulsifier for fluorinated oils, it is now focused on the problem that PFOA remains in human body, living entries, and also in environment. Therefore, the development of novel non-and low-remaining surfactants is necessary for the emulsification of fluorinated oils.In this work, as fluorochemicals having short fluoroalkyl group are known to remain in body only at low level, novel two hydrophile and two lipophile surfactants (Gemini) end-capped with fluoroalkyls were designed and prepared. In 2005-2006, SO3H type Gemini surfactants having various fluoroalkyls were successfully prepared from 1,4-pentadiene via addition of fluoroalkyl radicals as key step. In 2006-2007, a new route to COOH type Gemini surfactants via linking of two fluoroalkyl substituted malonates with several methylene spacers was also established.Their surfactant properties were studied based on the measurements of surface tension and surface pressure-Area curves. They showed excellent power of lowering surface tensions and quite lower critical micellar concentrations by 1〜2 orders in comparison with the corresponding convenient fluorinated surfactants. Moreover, based on the surface pressure-Area measurement, it was indicated that they have a superior ability to adsorb and arrange at the interface and to reduce oil/water interface tension, which will mean that they are promising as an alternative of PFOA. Next, the practical investigation of emulsification of fluorinated oils will be carried out.