CONFINEMENT OF POLYSOAPS IN MEMBRANE LYOTROPIC PHASES

We study the confinement of polysoaps in lyotropic smectic (L-alpha) a nd sponge (L-3) solutions of the nonionic surfactant pentaethylene gly col dodecyl ether (C12EO5) The polysoap is a hydrophobically modified polymer with n-tetradecyl sidegroups randomly grafted to a polyacrylat e backbone. Without the hydrophobic side chains the backbone polymer c annot be embedded into the intermembrane space, but confinement is ach ieved for a polysoap with as low as 1% of grafted groups. We measure b y small angle x-ray and neutron scattering an increase of the bending rigidity of the lamellar membranes as a function of polysoap concentra tion.