Article ID Journal Published Year Pages File Type
9676166 Colloids and Surfaces A: Physicochemical and Engineering Aspects 2005 17 Pages PDF
Abstract
The addition of nonionic surfactants (Brij-56 and Brij-58) induces ω induced percolation in conductance in nonpercolating AOT/IPM/water system at constant temperature. The percolation threshold (ωp) depends upon the content of the nonionic surfactants. The addition of NaCl at different concentrations shifts the ωp towards higher values of ω for both systems. The influence of total concentration of surfactants on the conductance behavior of (AOT + Brijs) at fixed Xnonionic (mole fraction of nonionic in total surfactant) at constant temperature has been investigated, and as the concentration increases, ωp shifts towards lower ω. The effect of Brij-58 is more pronounced than that of Brij-56 in inducing percolation. The temperature induced percolation behaviors of AOT reverse micelles in presence of nonionic surfactants of different types (Brijs, Spans, Tweens) have been studied. The effects of water content (ω), micelle concentrations, content of nonionics (Xnonionic), solvent (hydrocarbon oils and IPM) have also been investigated. The threshold percolation temperature (Tp) of the mixed reverse micellar systems has been found to be dependent on the type, head group configuration and content of the added nonionic surfactant, oil. The temperature induced percolation in mixed anionic (AOT)-nonionic (Igepal CO 520) and cationic (DDAB) and nonionics (Brij-56 and Brij-58) in IPM have been studied, and percolation and reverse percolation in conductance have been observed respectively. An attempt has been made to give an insight to the mechanism of percolation in conductance and microstructures in mixed reverse micellar systems. The activation energy, Ep has been estimated for the percolation process of AOT-nonionic(s) mixed reverse micellar systems. This parameter has been utilized to interpret the percolation phenomenon in these systems.
Related Topics
Physical Sciences and Engineering Chemical Engineering Colloid and Surface Chemistry
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