Interfacial composition and formation of w/o microemulsion with different amphiphiles and oils

Phase behavior, interfacial composition and thermodynamic properties of mixed surfactant (CTAB and Brij-58) derived w/o microemulsions with 1-butanol and 1-pentanol as cosurfactants and n-heptane and n-decane as oils

“…To estimate the concentrations of alkanol at the interface and in bulk oil to get the distribution constant (K d ) by the dilution method, the physicochemical rationale elaborated by Moulik et al [29][30][31] and Bayrak [32] was considered. Thus,…”

“…The dilution method has been also used by Moulik et al [29][30][31] to determine the interfacial composition, and energetics and structural parameters of different w/o microemulsion forming systems stabilized by ionic surfactants. Bayrak [32] has used the method on nonionic surfactant stabilized systems. Recently, Palazzo et al [33,34] have determined the interfacial compositions of CTAB/n-hexane/1-pentanol/water w/o microemulsion system using the dilution method and found satisfactory agreement with those obtained by using the pulsed gradient spin-echo NMR (PGSE-NMR) technique.…”

Physico‐Chemical Studies on Microemulsion: Effect of Cosurfactant Chain Length on the Phase Behavior, Formation Dynamics, Structural Parameters and Viscosity of Water/(Polysorbate‐20 + n‐Alkanol)/n‐Heptane Water‐in‐Oil Microemulsion

“…Moulik et al [32,33], Digout et al [34] and Wang et al [21] have systematically studied the effect of alkanol chain length on the interfacial composition and thermodynamic of formation of water-in-oil (w/o) microemulsions. The influence of primary and secondary alcohols on the partition equilibrium of phenol red has been studied by Sarma et al [35] Enzymatic activity dependence on the cosurfactant chain length was studied by Savelli et al [36] According to Bayrak [37], there was a direct correlation between the solubilization of water with the chain length of both the oils and n-alkanols. It was therefore concluded that higher water solubilization was a consequence of the partitioning of the cosurfactant at the oil water interface, although contradictory reports are also available in the literature [38].…”

On the equality of interfacial and critical composition

“…The method has been used [9][10][11][12][13][14][15][16][17][18] for determination of interfacial composition, bulk compositions, and some related thermodynamic properties and, although criticized by Gu et al [19] on the basis of energetic and distribution parameters from calorimetric data, its validity has been recently demonstrated by means of pulsed gradient spin-echo NMR [20]. According to this technique the interfacial composition of the W/O or O/W micro emulsions remain constant while changing the overall composition of the system by addition of the dispersed phase (oil for instance) and the cosurfactant.…”