Polymer enrichment decelerates surfactant membranes near interfaces.
Close to a planar surface, lamellar structures are imposed upon otherwise bulk bicontinuous microemulsions. Thermally induced membrane undulations are modified by the presence of the rigid interface. While it has been shown that a pure membrane's dynamics are accelerated close to the interface, we observed nearly unchanged relaxation rates for membranes spiked with large amphiphilic diblock copolymers. An increase of the polymer concentration by a factor of 2-3 for the first and second surfactant membrane layers was observed. We interpret the reduced relaxation times as the result of an interplay between the bending rigidity and the characteristic distance of the first surfactant membrane to the rigid interface, which causes the hydrodynamic and steric interface effects described in Seifert's theory. The influence of these effects on decorated membranes yields a reduction of the frequencies and an amplification of the amplitudes of long-wavelength undulations, which are in accordance to our experimental findings.
Institute for Complex Systems 1, Forschungszentrum Jülich GmbH, D-52425 Jülich.
F
F
Lipfert
Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, D-85747 Garching.
H
H
Frielinghaus
Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, D-85747 Garching.
O
O
Holderer
Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, D-85747 Garching.
S
S
Mattauch
Institute for Complex Systems 1, Forschungszentrum Jülich GmbH, D-52425 Jülich.
M
M
Monkenbusch
Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, D-85747 Garching and Jülich Centre for Neutron Science (JCNS), Outstation at SNS, Oak Ridge, USA.
N
N
Arend
Institute for Complex Systems 1, Forschungszentrum Jülich GmbH, D-52425 Jülich and Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, D-85747 Garching.
D
D
Richter