Details

Autor(en) / Beteiligte

• Tse-Ve-Koon, Kévin
• Tremblay, Nicolas
• Constantin, Doru
• Freyssingeas, Éric

Titel

Structure, thermodynamics and dynamics of the isotropic phase of spherical non-ionic surfactant micelles

Ist Teil von

• Journal of colloid and interface science, 2013-03, Vol.393 (1), p.161-173

Ort / Verlag

Amsterdam: Elsevier Inc

Erscheinungsjahr

2013

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• [Display omitted] ► The results confirm that C12E8 micelles are spherical and do not grow with temperature. ► A relation between the effective volume fraction of micelles, concentration and temperature is given. ► It is observed that the interaction potential is more complicated than what was described. ► Information on the dynamics of these mixtures is provided. ► Concentrated solutions exhibit a viscoelastic behaviour. We investigate a non-ionic surfactant (C12E8)/water binary mixture, over a wide range of concentrations and temperatures (i.e. 1–35wt.% of C12E8 and 10–60°C in temperature) by means of different experimental techniques: Small-Angle Neutron Scattering (SANS), Quasi Elastic Light Scattering (QELS) and High Frequency Rheology. The aims of this work are to provide information on structure, thermodynamics and dynamics of the isotropic phase of such a micellar system and, by combining these different types of information, to obtain a comprehensive image of the behaviour of this phase. Our results demonstrate that structural, thermodynamic and dynamic properties of these solutions are fully monitored by the temperature-induced changes in the ethylene–glycol chain hydration. They confirm that C12E8 micelles are spherical and do not grow in the investigated range of concentrations and temperatures. They demonstrate that the interaction potential between C12E8 micelles is more complicated than what was previously described, with an additional repulsive interaction. They allow us to put forward explanations for the Isotropic–Ordered phase transition as well as for the temperature behaviour of the viscosity of C12E8 micellar solutions. Our investigation provides new and valuable information on the dynamics of these mixtures that reflect the complexity of the interaction potential between the C12E8 micelles. It shows that concentrated solutions exhibit a viscoelastic behaviour that can be described by a simple Maxwell model.