Synthesis, characterization and applications of immobilized iminodiacetic acid-modified silica

Abstract

Porous immobilized iminodiacetic acid modified silica of the general formula S—(CH2)3—N(CH2COOH)2, (where S represents [Si—O] n siloxane network) has been prepared by replacement of the iodide in 3-iodopropyl modified silica with diethyliminodiacetate. The immobilized-diethyliminodiacetate ligand system (S-DIDA) was then hydrolyzed by hydrochloric acid to produce the immobilized iminodiacetic acid ligand system (S-IDA). The iodo functionalized modified silica (S-I) was prepared by polycondensation of Si(OEt)4 and (MeO)3Si(CH2)3I. The XPS and CP/MAS 13C NMR spectra showed that not all iodine atoms are replaced and that the hydrolysis of ethyl acetate groups are incomplete upon treatment with HCl. The immobilized iminodiacetic acid ligand system exhibits high potential for the uptake of various di- and trivalent metal ions such as (Mn2+, Fe3+, Co2+, Ni2+, Cu2 …