Micellization of Nonionic Surfactant Dimers and of the Corresponding Surfactant Monomers in Aqueous Solution

Studies of mixed surfactant solutions of cationic dimeric (gemini) surfactant with nonionic surfactant C12E6 in aqueous medium

“…The cmc values of pure C 12 E 6 at a given temperature are in good agreement with the reported values in the literature [34][35][36]. However, the cmc values for 16-4-16 that we determined are 10 times lower than the literature value determined by fluorescence technique [20] by Bhattacharya et al However, Zana et al [37] recently mentioned that the fluorescence technique is not a good method for determining cmc-at least in the case of gemini surfactants-and suggested that surface tension is a more suitable method for cmc determination. Tsubone et al [39] synthesized anionic gemini surfactants and also determined their cmcs in µM.…”

Surface and micellar properties of new nonionic gemini aldonamide-type surfactants

“…It is found that the difference between the cmc, equal 8.4 × 10 −4 M for cationic gemini compound-ethanediyl-1,2-bis[(dodecyldimethylammonium)bromide], and the corresponding monoquaternary ammonium analogues [20] is about two order of magnitude. Paddon-Jones et al [26] have recently published the cmc value of nonionic dimeric structure dimethylene-1,2-bis(N -hexaethyleneglycol dodecylamide) equal to 1.9 × 10 −5 M, about 10 times lower than that of the respective surfactant "monomer," N -methyl-N -hexaethyleneglycol dodecylamide, and-at the same time-slightly higher than the studied n-dodecyl bis(C n X) derivatives. Among the great variety of saccharide-derived surfactants those of classical structure have cmc values about two orders of magnitude lower than the tested aldonamide-type gemini compounds of equivalent chain length (e.g., 1.5 × 10 −4 and 2.5 × 10 −4 M for C 12 -MGA and C 12 -MLA, respectively [14], as well as 2.5 × 10 −2 and 1.9 × 10 −4 M for alkylglucosides, where alkyl is n-octyl and n-dodecyl, respectively [27]).…”

“…These results seem to be reasonable, taking into account that the character of the lactobionic group is more hydrophilic than that of the gluconic or glucoheptonic one. A considerable number of gemini surfactant investigations have been reported with respect to their "monomers" [20,26]. It is found that the difference between the cmc, equal 8.4 × 10 −4 M for cationic gemini compound-ethanediyl-1,2-bis[(dodecyldimethylammonium)bromide], and the corresponding monoquaternary ammonium analogues [20] is about two order of magnitude.…”

Preparation and dilute solution properties of model gemini nonionic surfactants

“…Although nonionic gemini surfactants have also been studied [8,11,12], they are always synthesized with hydrophobic moieties containing additional atoms (such as O, N, and S) in order to avoid the difficult, multistep synthesis necessary to produce exact gemini surfactant analogues of conventional poly(ethylene oxide) surfactants. Further, the majority of studies of these nonionic geminis have concentrated on synthesis, while the physical chemistry has been virtually ignored.…”