Lateral stretching of fluid membranes by grafted polymer brushes
Groupe de Dynamique des Phases Condensées, UMR
CNRS/UM2 No. 5581 CC 26, Université Montpellier II -
F-34095 Montpellier Cedex 05, France
Accepted: 27 November 2000
Amphiphilic copolymers are incorporated in a lyotropic lamellar phase: hydrophobic blocks adsorb onto the membranes whereas hydrophilic tails remain into the aqueous solvent and decorate the membrane. Small-angle X-ray or neutron scattering experiments show that the lamellar periodicity decreases as the polymer-to-surfactant weight ratio increases. This result can be quantitatively explained by bilayer's thinning due to the competition between stretching of the polymer brush in the smectic direction and stretching of the membrane in the lateral direction. This effect provides a new simple method to estimate the area stretching modulus of fluid membranes.
PACS: 61.12.Ex – Neutron scattering techniques (including small-angle scattering) / 61.25.Hq – Macromolecular and polymer solutions; polymer melts; swelling / 87.16.Dg – Membranes, bilayers, and vesicles
© EDP Sciences, 2001