title: Densely stacked multilamellar and oligovesicular vesicles, bilayer cylinders, and tubes joining with vesicles of a salt-free catanionic extractant and surfactant system.
abstract: In the phase diagram of an excellent extractant of rare earth metal ions, di(2-ethylhexyl) phosphate (HDEHP, commercial name P204), mixing with a cationic trimethyltetradecylammonium hydroxide (TTAOH) in water, a birefringent Lalpha phase was found, which consists of densely stacked multilamellar vesicles. The densely stacked multilamellar vesicles are remarkably deformed, as observed by means of cryotransmission electron microscopy (cryo-TEM). Further, self-assembled structures-oligovesicular vesicles, bilayer cylinders, and tubes joining with vesicles-were also observed. The self-assembled phase is transparent, anisotropic, and highly viscous, possessing elastic properties determined by rheological measurements. This is the first time that birefringent Lalpha phase with remarkably deformed amphiphilic bilayer membranes has been constructed through combining a hydrophobic organic extractant having double chains with a water-soluble surfactant having a single chain, which may direct primarily toward acquiring an understanding of the mechanism of salt-free catanionic vesicles and secondarily to determine if vesicle-extraction technology utilizing extractants is possible.
authors.affiliation: State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: Zaiwu
authors.initials: Z
authors.lastname: Yuan
authors.forename: Zhilei
authors.initials: Z
authors.lastname: Yin
authors.forename: Sixiu
authors.initials: S
authors.lastname: Sun
authors.forename: Jingcheng
authors.initials: J
authors.lastname: Hao
mesh_terms: D002412:Cations / Q000737:chemistry*; D020285:Cryoelectron Microscopy; D004548:Elasticity; D008051:Lipid Bilayers / Q000737:chemistry*; D008567:Membranes, Artificial; D008674:Metals, Rare Earth / Q000737:chemistry; D008823:Micelles; D043942:Nanotubes / Q000737:chemistry*; D012212:Rheology; D012997:Solvents; D013501:Surface-Active Agents / Q000737:chemistry*; D050337:Trimethyl Ammonium Compounds
chemical_list: D002412:Cations; D008051:Lipid Bilayers; D008567:Membranes, Artificial; D008674:Metals, Rare Earth; D008823:Micelles; D012997:Solvents; D013501:Surface-Active Agents; D050337:Trimethyl Ammonium Compounds; C009410:tetradecyltrimethylammonium