Title of article :
Formation and characterization of soy bean oil/surfactant/water microemulsions
Author/Authors :
Polizelli، نويسنده , , Marcos Alexandre and Telis، نويسنده , , Vânia Regina Nicoletti and Amaral، نويسنده , , Lia Q. and Feitosa، نويسنده , , Eloi، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2006
Pages :
7
From page :
230
To page :
236
Abstract :
Pseudoternary phase diagrams, at 25 °C, were constructed for the systems soy bean oil (SBO)/surfactant/water, with single anionic sodium bis(2-ethylhexyl)sulfosuccinate (AOT), nonionic monoolein (MO) and mixtures of these surfactants, showing the isotropic phase of W/O microemulsions (MEs). The area of ME formation in the phase diagrams was shown to be dependent of the relative amount of surfactants, being larger for MO:AOT equals to 2:1. Rheological and dynamic light scattering (DLS) studies indicated that the viscosity of the isotropic ME phase exhibited two different behaviors depending on composition. The viscosity of “dry” MEs initially decreased with increasing amount of water following a dilution line in the phase diagram, i.e., a constant surfactant:SBO percentage ratio. As the water content increased the relative viscosity attained a minimum and then increased. This minimum could be related to the transition between two ME regions, L2 and L 2 ′ , having different characteristics. DLS measurements confirm the existence of ordinary W/O ME droplets in the L2 region and suggest the existence of another structure in the L 2 ′ region. The size of the MEs droplets in L2 phase ranges from 3.6 to 16.5 nm, depending on composition of SBO, surfactant and water. Small angle X-ray scattering (SAXS) also indicates the existence of structures with different characteristics, for the SAXS curves exhibit a typical micelle asymmetrical peak at low scattering vector q for MEs in L2 but a symmetrical correlation peak at higher q vector in L 2 ′ .
Keywords :
Soy bean oil , rheology , Scattering techniques , Dry micelles , surfactant , microemulsions , Reverse micelles , phase diagram
Journal title :
Colloids and Surfaces A Physicochemical and Engineering Aspects
Serial Year :
2006
Journal title :
Colloids and Surfaces A Physicochemical and Engineering Aspects
Record number :
1792493
Link To Document :
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