| Numéro |
J. Phys. II France
Volume 3, Numéro 4, April 1993
|
|
|---|---|---|
| Page(s) | 515 - 530 | |
| DOI | https://doi.org/10.1051/jp2:1993148 | |
J. Phys. II France 3 (1993) 515-530
Transient behavior and relaxations of the L 3 (sponge) phase : T-jumb experiments
G. Waton1 and G. Porte21 Laboratoire d'Ultrasons et de Dynamique des Fluides Complexes associé au CNRS, Université Louis Pasteur, 4 rue Blaise Pascal, 67070 Strasbourg Cedex, France
2 Groupe de Dynamique des Phases Condensées associé au CNRS, Université Montpellier II, Case 026, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France
(Received 26 October 1992, accepted 29 December 1992)
Abstract
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
and
having very different magnitudes. We show that
is related to a conserved internal variable while
and
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 L
3 under transient tension. According to this interpretation,
corresponds to the relaxation of concentration fluctuations,
to that of the degree of symmetry of the structure and
to that of its density of connectivity. This picture actually accounts at least qualitatively for the experimental observation.
Moreover, the temperature dependences of
and
close to the sponge-to-lamellar transition temperature indicate that this transition is quite weakly first order.
42.20J - 82.70D - 66.10C - 61.25
© Les Editions de Physique 1993