Template Synthesis of Immobilized polysiloxane Diamine-Thiol tetraacetic acid Bi-Ligand system and its application for determination of metal ions

GRAPHICAL ABSTRACT

Abstract

A bi-functionalized porous solid diamine-thiol tetraacetic acid P‒(NN-SH)-TAA immobilized polysiloxane ligand system (where P represents [Si‒O]_n polysiloxane network, (NN-SH) represents both diamine and thiol groups, and TAA represents tetracetic acid group) has been prepared by modification of a post-polysiloxane bi-functional diamine-thiol ligand system P-(NN-SH) with ethylchloroacetate. The immobilized bi-ligand system was characterized by ¹³C‒NMR and Fourier transform-Infrared spectra. The bi-ligand system was used

for the extraction of divalent metal ions from aqueous solutions, which include Ni²⁺, Cu²⁺, and Pb²⁺, by the batch method at different time intervals and different pH values (3.5–6). The maximum metal uptake capacity values toward Ni²⁺, Cu²⁺, and Pb²⁺ were found to be 18.2, 125.7, and 138.89 mg/g ligand respectively at pH 5.5. The use of cetyltrimethylammoniumbromide should modify material porosity and therefore increase the metal ion uptake capacity of immobilized ligand system. The presence of bi-functional ligand groups at the silica matrix is to increase the metal uptake capacity of M(II) ions.

Keywords:

• Metal ions uptake
• bifunctionalized chelating ligands
• diamine-thiol tetraacetic acid
• immobilized polysiloxane biligand systems