| Numéro |
J. Phys. II France
Volume 6, Numéro 4, April 1996
|
|
|---|---|---|
| Page(s) | 529 - 542 | |
| DOI | https://doi.org/10.1051/jp2:1996196 | |
J. Phys. II France 6 (1996) 529-542
Anisotropic Small Angle Light and Neutron Scattering from a Lyotropic Lamellar Phase under Shear
Richard Weigel1, Jörg Läuger1, Walter Richtering1 and Peter Lindner21 Albert-Ludwigs-Universität Freiburg, Institut für Makromolekulare Chemie und Freiburger Materialforschungszentrum, Stefan-Meier Strasse 31, 79104 Freiburg, Germany
2 Institut Max von Laue-Paul Langevin, BP 156, 38042 Grenoble, France
(Received 21 September 1995, received in final form 15 December 1995, accepted 4 January 1996)
Abstract
The influence of shear on the lamellar phase of a semi-dilute solution (36% (w/w)) of tetra
ethylenglycol dodecylether (CH
3[ CH
2]
11[ OCH
2CH
2]
4OH, C
12E
4) in water was
investigated by Small Angle Light Scattering (SALS), Small Angle Neutron Scattering (SANS) and
rheology. A plateau modulus was determined by low amplitude oscillatory shear experiments. A strong
scattering peak perpendicular to the flow direction and a small peak along the flow direction were
observed in rheo-SANS. The rheo-SALS patterns were also anisotropic. At low shear rates, a four lobe
pattern was found in depolarized light scattering (H
) and scattering perpendicular to the flow
direction was observed in polarized scattering (H
). A butterfly pattern was found in light
scattering at high shear rates. The butterfly pattern was stable after cessation of shear, but it
was changed by slow shear flow. The scattering data can be explained by a shear induced formation of
deformed vesicles and the butterfly pattern might be correlated with an assembly of vesicles
disordered in the direction of shear.
© Les Editions de Physique 1996