Transient behavior and relaxations of the L3 (sponge) phase : T-jumb experiments

G. Waton , G. Porte

We report here on a systematic time resolved investigation of the transient behavior of the sponge phase after an abrupt temperature jump. We obtain evidence for three distinct relaxation times τ1, τ2 and τ3 having very different magnitudes. We show that τ1 is related to a conserved internal variable while τ2 and τ3 both correspond to the relaxations of unconserved thermodynamic variables. We propose an interpretation of the transient behavior based on the idea that the temperature jump essentially puts the membrane in L3 under transient tension. According to this interpretation, τ1 corresponds to the relaxation of concentration fluctuations, τ2 to that of the degree of symmetry of the structure and τ3 to that of its density of connectivity. This picture actually accounts at least qualitatively for the experimental observation. Moreover, the temperature dependences of τ2 and τ3 close to the sponge-to-lamellar transition temperature indicate that this transition is quite weakly first order.

Domaines: Articles anciens

G. Waton, G. Porte. Transient behavior and relaxations of the L3 (sponge) phase : T-jumb experiments. Journal de Physique II, 1993, 3 (4), pp.515-530. ⟨10.1051/jp2:1993148⟩. ⟨jpa-00247851⟩