Gold Extraction through Vesicles Self-Assembled by Cationic Gemini Surfactant and Sodium Deoxycholate

Abstract

A kind of self-assembled vesicles that composed of ionic liquid-type cationic gemini surfactant (C3H6-α, ω-(Me2N+C12H25Cl–)2, 12-3-12) and anionic biological surfactant (sodium deoxycholate, SDC) were constructed for Au(III) extraction. The appearance and microstructure of vesicles system were characterized by visual and TEM images. Compared to the zeta potential of pure vesicles system (+45 ± 1 mV), zeta potential of gold-loaded vesicles system reduced 15 ± 1 mv (changed to +30 ± 1 mV), which confirmed the mechanism of Au(III) was effectively extracted by vesicles through electrostatic interaction. The main influence factors including extraction equilibrium time, surfactants concentration, NaCl concentration, and pH on the extraction efficiency (E%) were explored. Furthermore, an effective method was devoted for gold(III) stripping. Through stepwise extraction and ligand-modified vesicles system, Au(III), Cu(II), and Fe(III) were separated from a mixed solution successfully. In short, an effective and po...