Alkanediyl-.alpha.,.omega.-Bis(Dimethylalkylammonium Bromide) Surfactants (Dimeric Surfactants). 5. Aggregation and Microstructure in Aqueous Solutions

A theoretical investigation of the influence of the second critical micelle concentration on the solubilization capacity of surfactant micelles

“…24,41,42 As a matter of fact, a second CMC could not be observed even at rather high surfactant concentrations for cationic gemini surfactants with a spacer group including six carbon atoms. 24,41,42 Hence, according to our present analysis gemini surfactants with a short spacer group are expected to have higher capacity to solubilize long-chain aliphatic hydrocarbons than micelle forming gemini surfactants with longer spacer groups. Comprehensive experimental systematic studies of the solubilization of long-chain hydrophobic components by gemini surfactant micelles are, unfortunately, still missing and experimental evidence of the role of spacer group length is, to our knowledge, not yet available.…”

“…16,32 Moreover, the length of the spacer group of gemini surfactants has been observed to have a huge impact on the location of the second CMC. 24,41 Gemini surfactants with a short spacer group, like 9E2Q-3-Q2E9 and 11E2Q-3-Q2E11 with a propylene group with three carbon atoms, usually display a second CMC at rather low surfactant concentrations, the location of which increases with increasing length of the spacer group. 24,41,42 As a matter of fact, a second CMC could not be observed even at rather high surfactant concentrations for cationic gemini surfactants with a spacer group including six carbon atoms.…”

“…24,41 Gemini surfactants with a short spacer group, like 9E2Q-3-Q2E9 and 11E2Q-3-Q2E11 with a propylene group with three carbon atoms, usually display a second CMC at rather low surfactant concentrations, the location of which increases with increasing length of the spacer group. 24,41,42 As a matter of fact, a second CMC could not be observed even at rather high surfactant concentrations for cationic gemini surfactants with a spacer group including six carbon atoms. 24,41,42 Hence, according to our present analysis gemini surfactants with a short spacer group are expected to have higher capacity to solubilize long-chain aliphatic hydrocarbons than micelle forming gemini surfactants with longer spacer groups.…”

Surfactant effects on the microstructures of Fe3O4 nanoparticles synthesized by microemulsion method

“…The long lifetime of the Gemini surfactant micelles prolongs the whole process of motion-collision exchange ( ex ) between different nanodomains, even equal or greater to the characteristic chemical reaction time ( r ). Thus, the [29,52], the micelle concentration of Gemini surfactant was larger than those of conventional surfactant, thus increasing the probability of effective collisions for material exchange, which is also beneficial to the formation of Fe 3 O 4 nanoparticles.…”

Monolayer Behavior of Asymmetrical Ester-type Tartaric Gemini Amphiphiles

“…According to Zana, however, the distance between two headgroups of C m C 6 C n Br 2 would be comparable to that between two similar monomer units. In other words, the -CH 2 6 -spacer chain would keep the two hydrophobic headgroups sufficiently apart 14 . Thus, it should be beneficial to investigate the effects of asymmetry in geminis with short spacer, on the exertion of hydrophobic interactions.…”