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RESEARCH PRODUCT
Viscoelastic properties of concentrated dispersions in water of soy lecithin
J. AparicioF. MolinaA.o. VilaMaria ManconiJ PendasJ. Figueruelosubject
ViscosityElectrokinetic phenomenaColloid and Surface ChemistryShear thinningChromatographyMaterials scienceChemical engineeringIonic strengthSonicationNewtonian fluidViscometerViscoelasticitydescription
Abstract Viscoelastic properties of soy lecithin dispersions at 60, 120, 180 and 240 g l−1 in water have been studied as a function of ionic strength (NaCl concentrations in the range 10−5–10−2 mol l−1) and of preparation method (sonication, freezing–unfreezing). Viscosity measurements of sonicated dispersions in a rotatory viscometer show Newtonian and plastic (Bingham) behavior, whereas the frozen–unfrozen dispersions show a spectacular change in their viscoelastic properties, that is, a non-Newtonian behavior with pseudoplastic characteristics and rheopexy. These properties have been related to electrokinetic characteristics of the segregated vesicles in each case. A decrease in ζ-potential (in absolute value) of vesicles results on an increase in the hysteresis loop area of the parents dispersions.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2003-07-01 | Colloids and Surfaces A: Physicochemical and Engineering Aspects |