Pouzot, Matthieu Mezzenga, Raffaele Leser, Martin E. Sagalowicz, Laurent Guillot, Samuel Glatter, Otto 2007-08-14 In the present study we demonstrate that a bulk inverse micellar cubic phase of <i>Fd</i>3<i>m</i> structure can be obtained by adding a hydrophobic component, such as the food-grade limonene, to the binary system monolinolein/water in a well-defined composition. The <i>Fd</i>3<i>m</i> structure studied in this work had a very slow kinetics of formation, as a consequence of partitioning of water into two types of micelle populations with different sizes. The <i>Fd</i>3<i>m</i> structure formed at a ratio of limonene oil to total lipids of α = 0.4 is stable in the bulk up to a maximum hydration of 12.68 wt % water, beyond which it starts to coexist with dispersed water. At full hydration, by combining small-angle X-ray scattering and available topological models, the inverse micellar cubic phase of <i>Fd</i>3<i>m</i> structure was shown to be formed by 16 small micelles and 8 larger micelles per cubic lattice cell (Q²²⁷ group), with radii of the micellar polar cores ranging between 1 and 3 nm and 149-168 monolinolein molecules per micelle depending on the water content. The temperature dependence of the structural and rheological properties of the <i>Fd</i>3<i>m</i> mesophase was investigated using SAXS, rheology, and turbidimetry. It appeared that the <i>Fd</i>3<i>m</i> phase underwent crystallization below 18 °C and began melting in an inverse microemulsion (L₂ phase) coexisting with water above 28.5 °C with complete melting obtained at 40-45 °C, as evidenced by SAXS and rheology. Macroscopic phase separation between the L₂ phase and excess water was observed with time at higher temperatures. The investigation of the viscoelastic properties of the <i>Fd</i>3<i>m</i> inverse discrete micellar cubic phase revealed a rheological signature similar to that of the bicontinuous cubic phases <i>Pn</i>3<i>m</i> and <i>Ia</i>3<i>d</i> observed in homologous binary systems. However, the <i>Fd</i>3<i>m</i> phase presented a complex set of slower relaxation mechanisms leading to a shift by 1 order of magnitude of the dominant relaxation times and whole relaxation spectrum, as compared to those of inverse bicontinuous cubic phases. These findings have been tentatively explained by (i) the multiple relaxation of micelles upon deformation, (ii) the small hydration level of the <i>Fd</i>3<i>m</i> phase, and (iii) the low temperature at which this phase can be observed. application/pdf https://folia.unifr.ch/global/documents/300689 https://folia.unifr.ch/documents/300689/files/mezzenga_sri.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1021/la701206a info:eu-repo/semantics/openAccess License undefined Langmuir. - 2007, vol. 23, no. 19, p. 9618-9628 info:eu-repo/classification/udc/53 Structural and rheological investigation of <i>Fd</i>3<i>m</i> inverse micellar cubic phases http://purl.org/coar/resource_type/c_6501