Viscoelasticity of the onion phase

We studied the viscoelasticity of two lyotropic lamellar systems prepared in the so-called ''onion phase''. This state consists of monodisperse multilamellar vesicles filling up space. The elastic (G') modulus is measured as a function of the frequency in the linear regime (small amplitude of the oscillations) for different onion sizes and characteristic distances between membranes. The results are interpreted in terms of the elastic deformation of smectic beads.