Eur. Phys. J. E 4, 337-341
Anomalous elasticity of an ordered lamellar liquid foamJ. Leng, F. Nallet and D. Roux
Centre de Recherche Paul-Pascal, CNRS, Avenue du Docteur Schweitzer, F-33600 Pessac, France firstname.lastname@example.org
(Received 7 August 2000)
We investigate experimentally the linear viscoelastic properties of a lamellar liquid foam as a function of the cell size and spatial organisation. The system consists of multilamellar vesicles generated by a simple shear flow on a lyotropic lamellar phase. The vesicles can be prepared either in an amorphous or a spatially ordered state. Their size is easily tunable in the range R=0.5-m. Whereas the shear modulus of the amorphous lamellar foam is alike that of usual liquid foams or concentrated emulsions and scales linearly with 1/R, the elastic modulus of the ordered foam is almost independent of the cell size. This result -probably the first describing the elasticity of an ordered foam-like system-remains unexplained.
62.20.Dc - Elasticity, elastic constants.
83.50.Fc - Linear viscoelasticity.
83.70.Jr - Liquid crystals; nematic, cholesteric, smectic, discotic, etc..
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2001