Order of Polyoxyethylene Chains in the Lamellar Phase of a Nonionic Surfactant

Abstract

Abstract Lamellar samples of aqueous tetraethylene glycol n-dodecyl ether in varying degrees of selective deuteration were studied by 2H NMR spectroscopy. Order parameter profiles for both the alkyl and oxyethylene head group chain have been obtained. A maximum in the order of the surfactant molecules was found to occur 3-4 methylene segments from the alkyl/headgroup interface on the alkyl chain. Order decreased rapidly with position on either side of this region giving an approximately symmetrical profile.