An X-ray study of brine swollen lyotropic lamellar phases

P. Bassereau , J. Marignan , G. Porte

The lamellar phases of two different quasi ternary systems (surfactant/alcohol/brine) are studied by X-ray scattering. In both cases the phase exhibits simple swelling behaviour when diluted with brine and the Bragg singularity persists at least up to 150 Å for the average interlamellar distance d. The comparison of the scattering patterns of the most swollen samples of the two systems shows that the out of plane fluctuations of the lamellar stacking are much larger in one case than in the other. This specificity is analysed in the light of the current theory on fluctuations in smectic media ; it indicates that, for the present brine swollen stackings, the Helfrich steric interaction is not the only dominant contribution to the effective intermembrane interactions.

Mots clés: disperse systems; organic compounds; smectic liquid crystals; swelling; water; X ray diffraction examination of liquids

Domaines: Articles anciens

P. Bassereau, J. Marignan, G. Porte. An X-ray study of brine swollen lyotropic lamellar phases. Journal de Physique, 1987, 48 (4), pp.673-678. ⟨10.1051/jphys:01987004804067300⟩. ⟨jpa-00210484⟩