Relationship between structure, surface activity, and micelle formation of some new bisquaternary isosteres of 1,5-pentanediammonium dibromides

Devı́nsky, Ferdinand; Lacko, I.; Bittererová, Fabiola; Tomečková, Ludmila

doi:10.1016/0021-9797(86)90417-0

Cited by 148 publications

(102 citation statements)

References 7 publications

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“…As mentioned earlier, in performing the calculations, the functional group is taken to be equivalent to that of a CH 2 unit for all cases, as if the surfactant is an m-5-m,2 Br − surfactant. Indeed, there is little dependence of the measured CMC values on the different functional groups [3].…”

Section: Origin Of 6ery Low Cmcsmentioning

confidence: 99%

Micelle formation and CMC of gemini surfactants: a thermodynamic model

Camesano

Nagarajan

2000

Colloids and Surfaces A: Physicochemical and Engineering Aspect

143

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Gemini surfactants possess a structure resembling a pair of conventional single chain surfactants covalently connected by a spacer. The spacer can vary in length and chemical structure. In this paper, the aggregation behavior of gemini surfactants is examined on the basis of a free energy model developed by extending our theory for conventional surfactants. Free energy contributions beyond those considered for conventional surfactants arise because of the spacer. They originate from the fact that (a) the spacer shields the hydrophobic core of the aggregate from contact with water, (b) the spacer constrains the distance between the head groups, thus imposing non-uniformity in charge distribution at the aggregate surface, (c) the spacer prevents the two linked tails from having a packing conformation inside the micelle identical to that of analogous unlinked single chain surfactants, and (d) the spacer can be partially buried inside the micelle core provided its length and the molecular interactions allow it. Illustrative calculations for gemini surfactants with tail lengths of 5 -16 carbon atoms and various spacers are discussed here. The spacers considered include the polymethylene chain and a combination of polymethylene chain with NCH 3 , O, S, and aromatic groups. The predicted critical micelle concentration (CMC), micelle aggregation number, sphere-to-rod transition parameter (K) and shape of aggregates are compared with available experimental data. A comparative analysis of the magnitude and shape dependence of the individual contributions to the free energy shows that the nonuniform charge distribution at the aggregate surface and the additional packing constraint on the tails, both originating from the short length of the spacer, play a central role in determining the equilibrium shape of the aggregates.

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Section: Origin Of 6ery Low Cmcsmentioning

confidence: 99%

Micelle formation and CMC of gemini surfactants: a thermodynamic model

Camesano

Nagarajan

2000

Colloids and Surfaces A: Physicochemical and Engineering Aspect

143

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“…Their physical and aggregation characteristics such as critical micelle concentration and surface properties [36][37][38][39][40][41], micelle aggregation number and size [42][43][44], antimicrobial activity [45], aggregate structure variability in aqueous solutions as a function of the spacer length [46], indicate unique properties and aggregation behaviour of this class of surfactants which predetermines them to be used in a broad range of applications.…”

Section: Introductionmentioning

confidence: 99%

Urea-based gemini surfactants: Synthesis, aggregation behaviour and biological activity

Pisárčik

Pupák

Devı́nsky

et al. 2016

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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“…The cmc values of C 10 SSC 10 , C 12 SSC 12 and C 14 SSC 14 have been determined to be 5.85, 0.90, 0.11 mM, respectively, by the conductivity measurements. That is to say, the cmc of C 10 SSC 10 is about 50 times larger than that of C 14 SSC 14 . Since the concentration of monomeric C 10 SSC 10 in C 10 SSC 10 -C 14 SSC 14 mixture is much larger than that of monomeric C 14 SSC 14 , the micelle composition is C 14 SSC 14 -rich even for equimolar C 10 SSC 10 -C 14 SSC 14 system.…”

mentioning

confidence: 89%

“…Therefore, we estimated the cmc of the dissymmetric gemini surfactant by using the linear relationship between log cmc and total carbon number (C n ) of two hydrophobic chains. The cmc of C 10 SSC 12 was estimated to be 2.23 mM from the experimental relation of log cmc = 2.10 -0.216 C n for C 10 SSC 10 , C 12 SSC 12 , and C 14 SSC 14 systems 14) . For C 10 SSC 10 -C 10 SSC 12 -C 12 SSC 12 ternary system which is shown in the first row of , the pseudo-phase separation model presuming ideal mixing i.e., f i = 1, predicts that the monomer concentrations of C 10 SSC 10 , C 1 0 SSC 1 2 and C 1 2 SSC 1 2 are 1.84, 0.83 and 0.14 mM, respectively.…”

Section: Dissymmetric Geminis By Disulfide Exchange In Micellesmentioning

confidence: 99%

Dissymmetric Gemini Surfactants Generated by Disulfide Exchange in Mixed Micelles

et al. 2010

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We found the generation of dissymmetric gemini surfactants from symmetric ones in aqueous micelle solutions of gemini surfactants with a spacer containing disulfide linkage. The equilibrium was attained during 5 h incubation at 25˚C with 1:2 ratio of symmetric to dissymmetric ones when the total concentrations were sufficiently high compared with monomer concentrations. The generation of dissymmetric form is attributed to the disulfide exchange between the spacer chains, which occurs in the mixed micelles of gemini surfactants with different hydrocarbon chains. The pseudo-phase separation model for micellization was successfully used to predict not only the cmc of binary and ternary mixtures composed of symmetric and dissymmetric gemini surfactants but also the monomer concentrations after the equilibrium. Reversibility of the disulfide exchange was ascertained by the generation of symmetric gemini surfactants from dissymmetric ones.

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Relationship between structure, surface activity, and micelle formation of some new bisquaternary isosteres of 1,5-pentanediammonium dibromides

Cited by 148 publications

References 7 publications

Micelle formation and CMC of gemini surfactants: a thermodynamic model

Micelle formation and CMC of gemini surfactants: a thermodynamic model

Urea-based gemini surfactants: Synthesis, aggregation behaviour and biological activity

Dissymmetric Gemini Surfactants Generated by Disulfide Exchange in Mixed Micelles

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