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

全氟辛酸（PFOA）是一种化学和生物稳定性良好的表面活性剂，已被广泛用作含氟油品的乳化剂，但PFOA在人体、生物体和环境中的残留问题一直是人们关注的焦点。因此，开发新型无残留和低残留表面活性剂对于含氟油的乳化是必要的。本工作中，由于已知具有短氟烷基的含氟化合物仅在体内残留较低水平，因此设计并制备了新型两种亲水性和亲脂性表面活性剂（Gemini）氟烷基封端。2005-2006年，以1，4-戊二烯为原料，通过氟烷基加成为关键步骤，成功制备了具有多种氟烷基的SO 3 H型Gemini表面活性剂。2006-2007年，又通过两个氟烷基取代的丙二酸酯与多个亚甲基间隔基的连接，合成了COOH型Gemini表面活性剂，并通过表面张力和表面压-面积曲线的测定，研究了它们的表面活性。它们具有很好的降低表面张力的能力，临界胶束浓度比相应的常规含氟表面活性剂低1 ~ 2个数量级。表面压力-面积法测定结果表明，它们具有上级的界面吸附和排列能力，并能降低油/水界面张力，有望成为PFOA的替代品。接下来，将进行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.