On the flocculation and re-dissolution of trivalent lanthanide metal ions by sodium dodecyl sulfate in aqueous solutions

Synthesis and aggregation properties of new biodegradable amphiphilic derivatives of p-tert-butylphenol for green separation of Gd(III) ions

“…Thus aggregation of the amphiphiles should be considered as both the competitive with and contributing to their binding with Gd(III) ions. Thus the above mentioned results indicate that the interaction of Gd(III) ions with the end carboxylates is tight enough to provide the predominant effect on the phase separation in the aqueous solutions of the amphiphilic molecules, which is in good confirmation with the previously reported regularities for long alkyl chain carboxylates [31,32]. Nevertheless the wrapping of polyetheleneoxide chains round [GdL 2 ] + complexes can be assumed as the additional interaction mode within the surfactantrich phase bound with Gd(III) ions, which differentiates the studied amphiphiles from the long alkyl chain carboxylates.…”

“…The turbidity can be enhanced by the increase of both pH and concentration of Gd(III), while it is restricted by the acidification to pH 2-3. These tendencies are quite different from the concentration dependent turbidity followed by re-dissolution in aqueous solutions of sodium dodecylsulfate and lanthanide ions [31]. The observed regularities are more close to the interactions of long chain sodium carboxylates with metal ions in aqueous solutions, which are dependent on pH, concentration and alkyl chain length [32].…”

The interaction of long chain sodium carboxylates and sodium dodecylsulfate with lead(II) ions in aqueous solutions

“…3) with these two carboxylates. Electrical conductivity is particularly valuable for the assessment of the effect of ionic [49,50] or non-ionic surfactants [51] on the structure of ionic solutions, because it follows modifications of complex electrolyte solutions, resulting from changes in the size and shape of moving particles and/or in the effective charge [52]. Since the specific conductance is a measure of the overall ion concentration in solution, the decrease in the specific conductance up to r equals 1.9 and 2.0, respectively, upon addition of sodium deca-and dodecanoates to 1 mM Pb 2+ aqueous solutions indicates a strong (probably mainly electrostatic) interaction between lead(II) and the carboxylate.…”

“…We have previously shown that the interaction between divalent or trivalent metal ions and alkanoates in aqueous solutions is quite different from that observed with sodium dodecylsulfate (SDS) [1,50]. With SDS, the maximum interaction concentration is not reached at charge neutralization, but at higher r values.…”

Thermodynamic study of the interaction between 5,10,15,20-tetrakis-(N-methyl-4-pyridyl)porphyrin tetraiodine and sodium dodecyl sulfate

“…Both explanations are in agreement with the formation of aggregates involving TMePyP 4+ and dodecyl sulfate (DS − ). This clearly indicates a strong, mainly electrostatic, interaction between the tetra-cationic porphyrin (TMePyP 4+ ) and dodecyl sufate [28,29]. Furthermore, the onset of aggregate formation seems occurs at SDS concentrations lower than 0.14 mM.…”