Synthesis and Surface Activity of Quaternary Ammonium Cationic Gemini Surfactants

A series of dimeric quaternary ammonium surfactants(m-5-m,m=8,12,16) were prepared from long-chain alkyl amine and 1,5-dibromic pentane,and their surface activities were examined using surface tension and conductometry.The results show that all products have good surface activities,and with increasing chain length,their CMC decreases monotonously,while γCMC decreases firstly and increases again.8-5-8 has the poorest surface activity among the three dimeric surfactants.