Undulations in Salt-Free Charged Lamellar Phases Detected by Small Angle Neutron Scattering and Neutron Reflectivity.
Undulations in Salt-Free Charged Lamellar Phases
Detected by Small Angle Neutron Scattering and Neutron
Reflectivity.
(186 K)
Salamat, G.; deVries, R.; Kaler, E. W.; Satija, S.;
Sung, L. P.
Langmuir, Vol. 16, No. 1, 102-107, 2000.
Keywords:
neutron scattering; neutron reflectivity
Abstract:
Neutron reflectivity of lamellar phases containing penta
ethylene glycol n-dodecyl ether, sodium decylsulfonate,
and D2O is measured at the solid-liquid interface. The
scattering length density profiles deduced from fits to
the reflectivity data show that undulations of the mixed
surfactant bilayers close to the solid-liquid interface
decrease as the molar ratio of ionic to nonionic
surfactant increases. This is consistent with recent
theoretical predictions. Small angle neutron scattering
measurements of these samples show both small angle
scattering and quasi-Bragg peaks. As the molar ratio of
ionic to nonionic surfactant increases, the low-q
scattering intensity decreases and higher order
quasi-Bragg peaks appear.
