Synthesis And Interfacial Properties Of Novel Silicone Surfactants

Trisiloxane surfactants have the simple structure and good interfacial properties, they have being widely used and researched. One of their outstanding features is their ability to reduce the surface tension of water down to the low value of 20mN·m-1. By comparison, typical organic surfactants reduce the surface tension of water down to atound 30mN·m-1. Moreovert, similar to other silicone surfactabts, trisiloxane surfactants have very low toxicity. In this text, three types of trisiloxane surfactants have being synthesized: AGE anion trisiloxane surfactants, cationic trisiloxane surfactants and nonion trisiloxane surfactants. Moreover, their surface intension, wettability and emulsibility were investigated. The results were as follows.(1) AGE anion trisiloxane surfactants can reduced the surface tension of water to 23.0mN·m-1 at the critical micelle concentration of 3.0×10-3g·mL-1,it has poor wettability and the emulsifying time was 80 s. AEG cationic trisiloxane surfactants can reduced the surface tension of water to 20.0mN·m-1 at the critical micelle concentration of 3.1×10-3g·mL-1, the wetting time was 15 s, the emulsifying time was 112 s. The results show that the wettability and emulsibility of AEG-ATSS were better than AEG-CTSS.(2) The critical micelle concentration of nonion trisiloxane surfactants NTSS-300, NTSS-400 and NTSS-1200 respectively were 9.2 ×10-5g·mL-1, 4.1×10-5g·mL-1 and 6.3×10-5 g·mL-1, the critical surface tension respectively were 22.5mN·m-1, 22.7 mN·m-1 and 27.1 mN·m-1. In addition, NTSS-300 has better wettability and NTSS-1200 has better emulsibility.(3) The critical micelle concentration of cationic trisiloxane surfactants CTSS and CTSS-500 respectively were 6.3×10-4g·mL-1 and 1.6×10-5g·mL-1. the critical surface tension both were 20.0 mN·m-1. CTSS-500 has better wettability and emulsibility. The results show that betaine cationic trisiloxane surfactants has better surface properties.In short, trisiloxane surfactants can reduced the surface tension of water to 20.0mN·m-1, otherwise, their wettability and emulsibility were relevant to their lon type and their chain length. If the hydrophilic chain has appropriate length, it has better wettability; if the hydrophilic chain was longer, it has better emulsibility.