Journal of Oleo Science
Online ISSN : 1347-3352
Print ISSN : 1345-8957
ISSN-L : 1345-8957
Detergents, Surfactants, Interface and Colloid
Structural Viscosity Induced by Depletion Effect in Stable Vesicle Dispersion
Asami MiyajimaRyo InoueErika OnishiMiyuki MiyakeRyo Hyodo
Author information

2019 Volume 68 Issue 9 Pages 837-845


Producing structural viscosity in colloidal dispersions, such as vesicles and capsules, prevents separation of dispersed particles by increasing the viscosity between them, which is advantageous in terms of usability. So far, the separation behavior of various particles has been studied; however, there are very few examples wherein a stable dispersion state was constructed and controlled. In this study, we produced stable dispersions induced by the depletion effect in mixtures of vesicles of cationic surfactant derived from triethanolamine-based esterquat (TEQ) and a specific dextrin derivative (SDD) as a non-adsorptive polymer. In the composition region, where 8 to 16% of TEQ vesicles and 1.2% or less of SDDs were mixed, the viscosity increased proportionally with the particle concentration, and it was observed that stable dispersions were produced by structural viscosity. Furthermore, the effects of TEQ and SDD concentrations, and SDD size on the structural viscosity and cohesive energy were investigated, which were similar to the depletion effect in the Asakura–Oosawa (AO) theory. From the results, it was suggested that the structural viscosity of the mixed dispersions (TEQ vesicles and SDDs) was produced by the aggregated TEQ vesicle networks induced by the depletion flocculation.

graphical abstract Fullsize Image
Related papers from these authors
© 2019 by Japan Oil Chemists' Society
Previous article Next article