Middle-phase microemulsions of green surfactant alkyl polyglucosides

The microemulsion behavior in the quaternary system alkyl polyglucoside (C8G1.46 , C10G1.54)/1-butanol/cyclohexane/water has been studied at 40℃ with the alcohol concentration scanning and the fishlike phase diagram methods. Increasing d at a constant causes a phase inversion from an oil-in-water microemulsion in contact with excess oil (Winsor I or 2 ) to a wa-ter-in-oil microemulsion in contact with excess water (Winsor II or 2) via a middle-phase microe-mulsion in contact with excess oil and water (Winsor III or 3). By using the simple mass balance equation and the HLB plane equation, the mass fraction of 1-butanol in the interfacial layer, S s2, the monomeric solubilities of APG and 1-butanol, S1 and S2, in the oil phase, and the mass frac-tions of APG and 1-butanol in the interfacial layer (C1 and C2 ) have been calculated, respectively. The effects of different alcohols, aqueous media and oils on the phase behavior and the composi-tion of the interfacial layer are also investigated. It is found that the alcohols with longer hydrocar-bon chain, oil molecules with smaller molecular volume and the addition of inorganic salt can in-crease the solubilization of the microemulsions .