牛磺酸改性POSS基巨型表面活性剂的制备及性能

Preparation and properties of taurine-modified POSS-based giant surfactants

摘要:

以3-缩水甘油醚氧基丙基三乙氧基硅烷和具有不同烷基链长度(甲基、异丁基、正辛基和十二烷基)的烷基三乙氧基硅烷为原料，通过硅氧烷水解缩合合成了七环氧基烷基POSS中间体，进而与牛磺酸通过氨基与环氧基开环反应合成了牛磺酸改性POSS基巨型表面活性剂七磺酸基烷基POSS。采用FT-IR、NMR、TEM和DLS对其进行了表征，通过表面张力、接触角、界面张力对其性能进行了测试。结果表明，当烷基链长为8的7Tau-POSS-Cn具有最优的表面活性、界面活性和润湿性，在水溶液中均匀分散呈球状胶束，平均粒径为135.5 nm，多分散指数为0.405；7Tau-POSS-C8溶液的临界胶束浓度为0.04 mol/L，最低表面张力为29.0 mN/m；浓度为0.01 mol/L的7Tau-POSS-C8可将油水界面张力降至5.821 mN/m，将油湿性聚四氟乙烯膜的水接触角降低至40°以下。

Abstract:

The taurine-modified POSS-based giant surfactants (7Tau-POSS-Cn, n= 1, 4, 8, 12) were synthesized through the ring-opening reaction of the amino group of taurine with the epoxy group. Heptaepoxide monoalkyl POSS intermediate (7EP-POSS-Cn, n= 1, 4, 8, 12) were synthesized through the hydrolysis of silanes using 3-glycidoxypropyltriethoxysilane (GPTES), methyltriethoxysilane (MTEOS), isobutyltriethoxysilane (TBTEOS), octyltriethoxysilane (OCTEOS), and dodecyltriethoxysilane (DOTEOS). The structure of 7Tau-POSS-Cn ( n= 1, 4, 8, 12 ) were characterized by FT-IR, NMR, TEM, and DLS. The surface activity, wettability, interfacial activity, temperature resistance, and salt resistance of 7Tau-POSS-Cn ( n= 1, 4, 8, 12 ) were tested through surface tension tester, contact angle tester, and interfacial tension tester. The results indicate that when the alkyl chain length of 7Tau-POSS-Cn is 8, 7Tau-POSS-C8 exhibits the most excellent surface activity, interfacial activity and wettability. It is uniformly dispersed in the aqueous solution in the form of spherical micelles, with an average particle size of 135.5 nm and a polydispersity index of 0.405. The critical micelle concentration of the 7Tau-POSS-C8 solution is 0.04 mol/L, and the lowest surface tension is 29.0 mN/m. The 7Tau-POSS-C8 at a concentration of 0.01 mol/L can reduce the oil-water interfacial tension to 5.821 mN/m and decrease the water contact angle of the oil-wet polytetrafluoroethylene membrane to below 40°.