Study of Environmentally Benign Synthesis of Mesoporous Silicas with New Fluorous Surfactant

1.含氟表面活性剂的合成以市售醇为原料，通过两步反应高产率合成了含氟表面活性剂1，一种季铵盐.根据FSM-16的合成，尝试以氟表面活性剂1为模板剂制备介孔二氧化硅，命名为FSM-R_f 11。首先，我们研究了反应时间和温度对1（0.1 M）与湿kanemite反应合成FSM-R_f 11的影响。反应温度的研究结果表明，在60 ~ 90℃的反应温度下，可以制备出孔径足够大、孔分布较窄的FSM-R_f_（11）。此外，FSM-R_f 11的孔径比使用长C_2烷基链的表面活性剂制备的FSM-12的孔径大<12>.含氟表面活性剂的回收和再利用1我们设计了一种方法来回收1，这是用于实际的FSM-R_f 11合成，从水的废物后，过滤的产物，用全氟溶剂萃取。首先，我们进行了初步的研究，选择性萃取1的水溶液中的1与几个全氟溶剂，和2，2，2-三氟乙基三氟乙酸酯（TFETFA）被发现是一个很好的溶剂，用于此目的的溶剂中检查。在FSM-R_f 11的实际合成中，当使用3.3g的1作为模板时，用TFETFA从水性废物中回收1.1g的1。表面活性剂1没有完全回收，因为1被认为保留在硅酸盐的中孔中。收集回收的1，并再次进行FSM-R_f 11的制备;然而，结果不太令人满意，因为回收的1的FSM-R_f 11的孔分布比新合成的1的FSM-R_f 11的孔分布宽得多。

1. Synthesis of Fluorous SurfactantFluorous surfactant 1, a quaternary ammonium salt, was synthesized from commercially available alcohol through two steps in high yield.2. Synthesis of FSMPreparation of a mesoporous silica with fluorous surfactant 1 as template, named FSM-R_f11, was tried according to the synthesis of FSM-16. At first we studied the effect of reaction time and temperature in the reaction of 1 (0.1 M) with wet kanemite on a synthesis of FSM-R_f11. The results of a study of reaction temperature showed that FSM-R_f11, which possessed enough pore size and narrow pore distribution, could be prepared at reaction temperature of 60℃ to 90℃ we examined. Furthermore, the pore size of FSM-R_f11 proved to be larger than that of FSM-12, which was prepared with a surfactant with a longer C_<12>-alkyl chain.3. Recovery and Re-use of Fluorous Surfactant 1We designed a method to recover 1, which was used for actual FSM-R_f11 synthesis, from the aqueous waste after filtration of the product by extraction with perfluoro solvents. At first, we carried out a preliminary study for selective extraction of 1 from the aqueous 1 solution with several perfluoro solvents, and 2,2,2-trifluoroethyl trifluoroacetate (TFETFA) was found to be a good solvent for this purpose among the solvents examined. In the actual synthesis of FSM-R_f11, 1.1 g of 1 was recovered from the aqueous waste with TFETFA when 3.3g of 1 was used as a template. Surfactant 1 was not recovered completely because 1 was thought to remain in the mesopores of silicates. The recovered 1 was collected, and subjected to preparation of FSM-R_f11 again; however, the results were less satisfactory as the pore distribution of FSM-R_f11 with recovered 1 was much wider than that of FSM-R_f11 with freshly synthesized 1.