Synthesis and Properties of Ammonium Salt Gemini Surfactants with Diethylammonium Headgroups and Diester Spacer

A series of ammonium salt Gemini surfactants(Gemini C10,Gemini C12,Gemini C14,Gemini C16,Gemini C18 whose hydrophobic chain numbers are 10,12,14,16,18)with diethylammonium headgroups and diester spacer were synthesized by using bromoalkane,diethylamine,chloroacetyl chloride and ethanediol.The surface activities and aggregate morphology were studied.When the temperature went up,the critical micelle concentration(cmc) of Gemini C10 decreased,but the cmc of the rest four Gemini surfactants increased.The surface tension of the five Gemini surfactants over 25 ℃ reveals that the cmc of those Gemini surfactants will decrease as the hydrophobic chain length increases.Vesicle whose size distribution is approximately forty nanometer to two hundred nanometer formed above their cmc in this series of compounds.