The ion-pair formation between dodecylsulfate and ammine-complexes of copper(II), nickel(II), zinc(II), palladium(II) and platinum(II), and the extraction behavior of the ammine-complexes by using sodium dodecylsulfate

Surfactant Gel Extraction of Metal Ammine Complexes using SDS and KCl at Room Temperature, and a Small-angle X-ray Diffraction Study of the Surfactant Phase

“…The solubility product of an MDS, K sp , is defined as follows: -46 -extraction (E %) is described as follows: and PdDS, respectively. These values almost agree with those obtained at 0°C using SDS [14]. In general, the previous metal separations have been based on the dependence of pH and/or the ligand concentration on metal extractability.…”

“…However, we previously reported that an unexpected decrease in extractability was observed at low metal concentrations for the ion-pair extraction of dodecylsulfate anions (DS -) and cationic metal ammine complexes. This decrease has been explained by the solubility of metal ion pairs (MDSs) at low temperature around 0°C [14]. In the present study, the phase separation and extraction of the metal ammine complexes at room temperature were examined by the addition of salts such as KCl to anionic surfactant systems of SDS.…”

“…As shown in Figure 4, the percent extraction of metal complexes into the surfactant phase decreased at low metal concentrations. This phenomenon can be explained by the solubility of the ion pair of DS -and M(NH 3 ) n 2+ , where M is palladium, nickel, copper, or zinc [14]. The solubility product of an MDS, K sp , is defined as follows: -46 -extraction (E %) is described as follows: and PdDS, respectively.…”

Surfactant Gel Extraction of Gold(III), Palladium(II), Platinum(II), and Lead(II) as Thiourea-complexes

“…These decreases can be explained by the unique solubility product of ion-pairs between anionic surfactants and cationic-complexes. 6 In the presence of a surfactant gel, the concentration of monomers ([DBS -]aq) was independent from the initial surfactant concentrations and constant in the aqueous phase. The solubility product of the ion-pair Ksp is defined as follows: …”

“…6 Thiourea, as well as ammonia, is an important chemical substance because it has a large number of industrial utilizations, and is economically easy to obtain. Thiourea forms simple coordination-type complexes with numerous heavy metals, most of which are colorless and soluble in water.…”