UPTAKE OF DIVALENT METAL IONS (Cu²⁺, Zn²⁺, AND Cd²⁺) BY POLYSILOXANE IMMOBILIZED DIAMINE LIGAND SYSTEM

Abstract

Porous solid siloxane polymers carrying diamine functional group of formula P–(CH₂)₃NH–CH₂CH₂NH₂ (where P–represents a silica-like siloxane framework) have been prepared by replacement of the iodine in iodopolysiloxane with ethylenediamine. The iodofunctionalized polysiloxane was prepared by polycondensation of Si(OEt)₄ and (MeO)₃Si(CH₂)I. The polysiloxane diamine ligand system exhibits high potential for preconcentration of divalent metal ions (Cu²⁺, Zn²⁺, and Cd²⁺). The tendency to chemisorb these divalent metal ions by the diamine ligand system at the optimum conditions was found in the order: Cu²⁺ > Zn²⁺ > Cd²⁺. Diamine ligand system suffers from leaching of ligand containing groups upon treatment with acidic solutions.

Keywords:

• Metal uptake
• Diamine ligands
• Polysiloxanes
• Immobilizedpolysiloxane ligand systems

Acknowledgments