The Surface Activities of Bivalent Metal Alkyl Sulfates. I. On the Micelles of Some Metal Alkyl Sulfates

Abstract

Dodecyl sulfates of bivalent nickel, cobalt, copper and magnesium were synthesized, and studies were carried out on the CMC values of these detergents, the effects of the added electrolytes on these CMC values, on micellar molecular weights, and on micellar charges. The CMC values of the detergents were independent of the kind of metal, and the CMC value of 1.2×10−3 mol./l. was obtained. The micellar aggregation numbers of bivalent metal dodecyl sulfates were of the order of 100, which is about twice that of sodium dodecyl sulfate. The dissociation degrees of the micelles were also evaluated from the conductivity data. The α values obtained were 0.66 for cobalt, 0.60 for copper and 0.42 for magnesium. The dissociation degree of the copper dodecyl sulfate micelle was also estimated to be 0.52 from the depression of the CMC value by the added electrolyte; this figure is approximately the same as the value of 0.60 obtained from the conductivity data. These results suggest that the fundamental factor responsible for determining the surface activities of bivalent metal dodecyl sulfates is the valency of the gegenion and that the kind of metal has little or no detectable effect on them.

Heat of micelle formation: Effect of counterions with concentrated, diffused, and separated electric charges

“…The values of MTl~eat are also listed in Table 1, together with those of MTR determined by CMC and solubility curves for comparison. All MTRheats are higher than MTR for the surfactants with divalent counterion whose aggregation number is 90 or more judging from their CMCs and those of anionic surfactants with divalent cationic counterion [13]. On the other hand, every MTR~eat for the monovalent counterion is lower than the usual MTR, which suggests that a dissolution of solid surfactant is taking place below the MTR and that the endothermic heat due to the dissolution plays a larger role than the exothermic heat of micelle formation for the surfactants of smaller aggregation number.…”

Structural characterization of solid trivalent metal dodecyl sulfates: from aqueous solution to lamellar superstructures

“…The synthesis of metal dodecyl sulfates, such as Cu(DS) 2 and Zn(DS) 2 , was first reported by Matuura et al who used the addition of SDS to a solution of the metal nitrate or chloride. [26][27][28] Firouzabadi et al synthesized Al(DS) 3 ?H 2 O and investigated its successful application in the Michael addition of indoles and pyrrole to a,b-unsaturated electron-deficient compounds in aqueous media at room temperature. In this study, they found that the catalytic activity of Al(DS) 3 ?3H 2 O is greater than that of Sc(DS) 3 .…”

Metallosurfactants Consisting of Amphiphilic Ligands and Transition Metals: Structure, Bonding, Reactivity, and Self-assembling Property

“…The lower CMC value of the Cu (II) -containing MS is attributed to the tendency of Cu (II) to adopt five-coordinate geometries, resulting in a marginally smaller head group. The ligand structures (12)(13)(14) were expanded in order to reveal the structurefunction relationship for the interfacial properties 9,10,33) . Cyclic peptides are also known to act as ionophores, wherein metal ions can be encapsulated within the inner cavity.…”

“…Glorius et al reported a combination of an NHC ligand and a structurally simple surfactant (20) with an Au (I) complex, Fig. 5 Structures of amphiphilic macrocyclic ligands (11)(12)(13)(14)(15) . T. Taira as shown in Fig.…”