Adsorption and aggregation behavior of Gemini surfactants with organic counterions

Gemini quaternary ammonium salts are synthesized by the one-step method which are GC-BA with a counterion of benzene sulfonate and GC-MA with a counterion of methanesulfonate. Then, the expected structure is proved by FT-IR, ESI-MS, H-1 NMR, and H-1-H-1 COSY. Most importantly, the adsorption behavior at various interfaces and the aggregation properties in aqueous solutions are investigated. The adsorption circumstances when the equilibrium is reached at the gas/liquid interface are evaluated by surface tension (ST) tests, while the short-term kinetic process is assessed by dynamic surface tension (DST) measurements. The adsorption at the gas/liquid/solid triple-phase is characterized by the contact angle, and the adsorption at the oil/water interface is expressed by oil/water interfacial tension (ITF). Finally, the aggregation properties are illustrated by conductivity measurements. In summary, some basic theoretical data for the new Gemini quaternary ammonium salts with organic counterions can be provided.