Role of surfactants in the behavior of emulsion liquid membranes - development of new surfactants

Surfactants play an important role in the emulsion liquid membrane (henceforth ELM) process. However, only two commercial surfactants have been used so far, Span 80 and polyamine. Relatively little attention has been spent in searching for other suitable surfactants. In order to develop new surfactants for the ELM process, in this study a series of derivatives of glutamic acid dialkyl esters and dialkyl-type quaternary ammonium salts were synthesized. Copper extraction by ELM was carried out in a stirred cell using these surfactants. It was found that glutamic acid dioleyl ester was a more suitable surfactant for the ELM process than Span 80 and polyamine as regards break-up, swelling and demulsification of the W/O emulsion, and enrichment of copper.