标题：Equilibrium, thermodynamics and kinetics study on Au(III) extraction by gemini surfactant with different spacer length
作者：Xiang Z.; Wang S.; Yang Y.; Xin X.
作者机构：[Xiang, Z] School of Chemistry and Chemical Engineering, Key Laboratory for Special Functional Aggregate Materials of Education Ministry, Shandong Uni 更多
通讯作者地址：[Yang, Y] School of Chemistry and Chemical Engineering, Key Laboratory for Special Functional Aggregate Materials of Education Ministry, Shandong Univ 更多
来源：Separation Science and Technology (Philadelphia)
关键词：gemini surfactant; Gold extraction; kinetics; spacer lengths; thermodynamics
摘要：The effect of spacer lengths of imidazolium gemini surfactant [C14-n-C14im]Br2 (n = 2, 4, 6) on the equilibrium, thermodynamics and kinetics of Au(III) extraction from hydrochloric acid medium were investigated in this article. The thermodynamic parameters, including the changes in enthalpy (ΔH*), entropy (ΔS*) and Gibbs free energy (ΔG*) were determined. The values of ΔH* demonstrated that the extraction of Au(III) by [C14-n-C14im]Br2 was endothermic at first and exothermic at last. The kinetics study found that extraction rate became faster when the spacer lengths were increased. Moreover, kinetics results demonstrated that the diffusion is the controlling step, and the mass transfer coefficients of Au(III) in the investigated systems indicated that the resistance of mass transfer was smaller when the spacer lengths was longer. The studies of interfacial tension further confirmed the better extractability of [C14-n-C14im]Br2 with longer spacer lengths. Our results reveal efficient and sustainable gold separation. © 2018, © 2018 Taylor & Francis.