title: Extraction of metal cations by polyterephthalamide microcapsules containing a poly(acrylic acid) gel.
abstract: Polyterephthalamide microcapsules containing a poly(acrylic acid) gel as a macromolecular ligand (PAA-CAPS) were prepared using an original two step polymerization process in a water-in-oil inverse emulsion system. A polyamide microcapsule containing acrylic acid, initiator and cross-linking agent, is formed by interfacial polycondensation of terephthaloyl dichloride with hexamethylenediamine. In situ radical polymerization of the microcapsule core acrylic acid is initiated to obtain encapsulated poly(acrylic acid) gel. Reference polyamide microcapsules, i.e. without ligand (CAPS), were also synthesized. The mean diameter of synthesized microcapsules was 210 microm, and the microcapsule wall thickness was evaluated by SEM and TEM observations of microcapsule cross-section cuts. The microcapsule water content was determined by thermogravimetric experiments. The extractabilities of Cu(II), Ni(II), Co(II) and Zn(II) into PAA-CAPS were examined. The stripping of the various cations can be promoted in diluted hydrochloric acid solutions.
authors.affiliation: Ecole de Chimie, Polymères et Matériaux, CNRS UMR 7512, Strasbourg, France. Laguecira@ecpm.u-strasbg.fr
authors.forename: A
authors.initials: A
authors.lastname: Laguecir
authors.forename: B
authors.initials: B
authors.lastname: Ernst
authors.forename: Y
authors.initials: Y
authors.lastname: Frère
authors.forename: L
authors.initials: L
authors.lastname: Danicher
authors.forename: M
authors.initials: M
authors.lastname: Burgard
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D002214:Capsules; D002411:Cation Exchange Resins; D005782:Gels; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D008024:Ligands; D008670:Metals / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D010795:Phthalic Acids / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D013818:Thermogravimetry
chemical_list: D000180:Acrylic Resins; D002214:Capsules; D002411:Cation Exchange Resins; D005782:Gels; D007202:Indicators and Reagents; D008024:Ligands; D008670:Metals; D010795:Phthalic Acids; D011108:Polymers; C073843:poly(4-phenylene terephthalamide); C006903:carbopol 940