In addition to the DLS analysis, these samples were investigated by TEM as shown in Fig. 7. At d20 and b8, the droplets before polymerization are composed of an inverse micellar fluidL2 with pockets filled with water. The images confirmed what we found by DLS measurements; we indeed obtained spherical particles of about 100 nm (Fig. 7, left). We also chose to work at d83 because at this d value the liquid crystalline phase dispersed into the droplets is very different than a microemulsion (Fig. 8,left); the droplets are called hexosomes and contain an inverse hexagonal phase, i.e. consisting in ordered elongated channels filled with water (see Fig. 8, right). At d83 and b8 we did not observe spherical particles but aggregated needles (Fig. 7, right). The polymerization at d83 brought about a problem of stability for the liquid crystalline phases. Indeed, d being the balance between the lipid and the hydrophobic monomer (styrene), the droplets contain 83% of lipid and only 17% of the polymerizable monomer at d83. This small content of styrene is the clue to understand what happened to the emulsion droplets during the polymerization process. As we explained previously, the internal structure of the emulsion droplets called hexosomes are water channels stabilized by the lipid surfactant (DU); the styrene is confined between these channels in the oil phase.
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