Gemini surfactants solubilization

The next section discusses chemical structures, synthesis, and purification of gemini surfactants. Section III reviews the behavior of gemini surfactants in solutions below the CMC. Section IV deals with their behavior at interfaces. The fifth section reviews micelle formation and solubilization. Section VI deals with micelle properties. Microstructure of aqueous solution of gemini surfactants, rheology of these solutions, and mixed micellization are considered in the following three sections. Section X deals with the phase behavior of... 

Devinsky et al. [36] studied in detail the solubilization of tran -azobenzene, a typical aromatic molecule, by micellar solutions of gemini surfactants [CmH2m+iN (CH3)2, Br ]2(CH2). The solubilizing capacity Sc, calculated from their data and expressed in moles of solubilized tran -azobenzene per mole of surfactant, increased nearly linearly with mats = 6, a result similar to that for conventional surfactants, reflecting the nearly linear increase of volume of hydrophobic pseudo phase with m. The results in Fig. 9 show the effect of the spacer carbon number, atm = 10. The solubilizing capacity is a maximum at an value around 6, close to that where the CMC vs. s plot goes through a maximum. This result was interpreted in terms of spacer flexibility and micelle structure [36]. 

Dam et al. [94] reported that the solubilizing capacity of the gemini surfactants [CmH2 ,+iN (CH3)2, Br ]2(CH2) for toluene and n-hexane is larger than for the corresponding monomeric surfactants. 

Esumi et al. showed that in the adsorbed state on silica [84], titanium dioxide [85], and laponite clay [86], the gemini surfactant 12-2-12, 2Br has a lower solubilizing power per mole of dodecyl chain than its corresponding monomer, DTAB, for 2-naphthol. 

The chapter is organized as follows. Section II briefly recalls the theoretical aspects of micellar dynamics and the expressions of the relaxation times characterizing the main relaxation processes (surfactant exchange, micelle formation/breakdown). Section III reviews studies of micellar kinetics of various types of surfactants conventional surfactants with a hydrocarbon chain, surfactants with a fluorinated chain, and gemini (dimeric) surfactants. Section IV deals with mixed micellar solutions. Section V considers the d5mamics of solubilized systems. Section VI reviews the dynamics of sur-... 

---