Protonated dye-surfactant ion pair formation between neutral red and anionic surfactants in aqueous submicellar solutions

Specific interactions of anions and pre-micelles in the alkaline fading of crystal violet carbocation

“…Gohain et al [34] investigated the spectral and surface tension behaviors of aqueous neutral red in the presence of anionic surfactants in their submicellar concentration ranges and suggested the formation of a 1:1 dye-surfactant ion pair. The ion pair was found to behave like a nonionic surfactant having lower CMC than that of the corresponding pure surfactant.…”

“…The same hydrolysis reaction was also studied in mixed system comprising ␣-cyclodextrin and a micelle-forming surfactant, cetyltrimethylammonium chloride (CTACl) [31]. In systems involving ionic dyes and charged surfactants, smaller species, known as dye-rich micelles or premicellar aggregates, are often formed before the formation of normal micelles [20,[32][33][34]. The formation of ion pairs between the ionic dye and oppositely charged surfactant monomers through hydrophobic as well as electrostatic interactions leads to the formation of such pre-micelles [20,32,34].…”

“…In systems involving ionic dyes and charged surfactants, smaller species, known as dye-rich micelles or premicellar aggregates, are often formed before the formation of normal micelles [20,[32][33][34]. The formation of ion pairs between the ionic dye and oppositely charged surfactant monomers through hydrophobic as well as electrostatic interactions leads to the formation of such pre-micelles [20,32,34]. Hence, the interaction in the pre-micellar region (where surfactant molecules remain as monomers or small surfactant assemblies) will not be the same as that operating in the post-micellar region and such interaction will possibly influence the reaction rate in a different manner.…”

Effect of [C n mim][Br] Based Ionic Liquids on the Aggregation Behavior of Tetradecyltrimethylammonium Bromide in Aqueous Medium

“…This property has been utilized in the spectrophotometric determination of metal ions and to improve spectral characteristics of colored systems. Several researchers have studied a range of dyes to study the aggregation behavior of the ionic surfactants [85][86][87][88][89]. The aggregation behavior of SDS, in a range of RTILs with varied alkyl chain lengths ranging from methyl to octyl, was studied using 8ANS as the dye [27].…”

Stabilization of diketo tautomer of curcumin by premicellar anionic surfactants: UV–Visible, fluorescence, tensiometric and TD-DFT evidences

“…The type of interactions depends mostly on the chemical structure and nature of both of the interacting compounds [31]. Surface tensiometric studies showed that some ionic surfactants exhibit two distinct CMC's in the presence of some oppositely charged dyes where the dye-surfactant ion pairs behave like nonionic surfactants in the submicellar concentration range [32][33][34][35].…”