title: Effect of shear on vesicle and lamellar phases of DDAB/lecithin ternary systems.
abstract: The influence of shear flow on bilayer structures (vesicle and planar lamellar phases, L(α)), formed in DDAB/lecithin ternary systems, is studied by means of conventional rheology, Rheo NMR, and optical microscopy. The vesicles in the diluted (Lam(1)) phase are polydisperse multilamellae which turn into smaller monodisperse vesicles under shear. The concentrated (Lam(2)) phase is formed by non-oriented lamellae that do not surprisingly exhibit any pronounced shear-induced alignment prior to the transition into giant multilamellar vesicles. The biphasic region (Lam(1)+Lam(2)) shows a mosaic texture with a powder pattern indicating the prevalence of lamellae that transform into onions under shear.
authors.affiliation: Department of Chemistry, University of Calabria, Rende 87036, Italy. youssry@unical.it
authors.forename: Mohamed
authors.initials: M
authors.lastname: Youssry
authors.forename: Luigi
authors.initials: L
authors.lastname: Coppola
authors.forename: Isabella
authors.initials: I
authors.lastname: Nicotera
authors.forename: Gönül
authors.initials: G
authors.lastname: Ar
authors.forename: Claudia
authors.initials: C
authors.lastname: Schmidt
mesh_terms: D054709:Lecithins / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008853:Microscopy; D044367:Phase Transition; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012212:Rheology; D014783:Viscosity
chemical_list: D054709:Lecithins; D000644:Quaternary Ammonium Compounds; C046112:didodecyldimethylammonium