title: Coacervation of surface-functionalized polymerized vesicles derived from ammonium bromide surfactants. Application to the selective speciation of chromium in environmental samples.
abstract: The potential of polymerized vesicle coacervates made up of ammonium bromide surfactants for the extraction of metallic ions from natural waters was examined for the first time. Linear linked polymerized vesicles prepared by UV excitation of (4-carboxybenzyl)bis[2-(10-undecenoyloxy)ethyl]methylammonium bromide monomer were characterized, and several factors affecting their phase behavior were investigated. Evidently, the permeation of metallic elements through the polymeric membrane was found to be sensitive to ionic radius excluding ions larger than the interbilayer space of the vesicle assembly. To this effect, Cr(3+) ions could selectively diffuse through the polymeric membrane. Optimization of vesicle structure and surface charge were the regulating parameters in exploiting this unique feature toward the analytical speciation of Cr species in natural waters. Detection limits as low as 0.1 microg L(-1) were achieved by preconcentrating only 10 mL of sample volume with recoveries in the range of 97.0-105.5% and very good reproducibility (RSD = 1.51%).
authors.affiliation: Department of Chemistry, University of Ioannina, 45110, Ioannina, Greece.
authors.forename: Nikolaos I
authors.initials: NI
authors.lastname: Kapakoglou
authors.forename: Dimosthenis L
authors.initials: DL
authors.lastname: Giokas
authors.forename: George Z
authors.initials: GZ
authors.lastname: Tsogas
authors.forename: Athanasios G
authors.initials: AG
authors.lastname: Vlessidis