title: The effect of polymeric supports and methods of immobilization on the performance of an optical copper(II)-sensitive membrane based on the colourimetric reagent Zincon.
abstract: A comparative study on the effect of different immobilization methods and matrix materials on the performance of copper(II)-sensitive membrane layers is presented. The indicator dye Zincon was immobilized in hydrophilic and hydrophobic polymers by various methods including: (a) physical entrapment of the Zincon-tetraoctylammonium ion pair in plasticized PVC, hydrogel, polystyrene, ethyl cellulose, poly-HEMA, AQ-polymer and in sol-gel glass; (b) electrostatic immobilization on an anion exchanger cellulose; and (c) covalent immobilization on cellulose via a sulfatoethylsulfonyl reactive group. The response to copper(II) ion was evaluated kinetically via the initial slope of the change in absorbance within 1 min. Layers made of hydrogel and PVC provide the highest sensitivity, while covalent immobilization is the most reproducible one, and sol-gel layers display the best mechanical stability.
authors.affiliation: Institute of Organic Chemistry, Karl-Franzens University Graz, Heinrich St. 28, 8010 Graz, Austria.
authors.forename: I
authors.initials: I
authors.lastname: Oehme
authors.forename: S
authors.initials: S
authors.lastname: Prattes
authors.forename: O S
authors.initials: OS
authors.lastname: Wolfbeis
authors.forename: G J
authors.initials: GJ
authors.lastname: Mohr