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

• Published in: Journal of sol-gel science and technology 2003-09, Vol.28 (2), p.255-265
• Main Authors: EL-NAHHAL, Issa M, ZAGGOUT, Farid R, NASSAR, Mona A, EL-ASHGAR, Nizam M, MAQUET, Jocelyne, BABONNEAU, Florence, CHEHIMI, Mohamed M
• Format: Article
• Language: English
• Subjects: Aqueous solutions; Chemistry; Cobalt; Colloidal gels. Colloidal sols; Colloidal state and disperse state; Copper; Ethyl acetate; Exact sciences and technology; Ferric ions; General and physical chemistry; Hydrochloric acid; Iodine; Leaching; Ligands; Manganese ions; Metal ions; Nickel; NMR; Nuclear magnetic resonance; Silicon dioxide; X ray photoelectron spectroscopy
• ISSN: 0928-0707; 1573-4846
• DOI: 10.1023/A:1026093419515

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+ and Zn2+). Complexation of the iminodiacetate ligand system for the metal ions at the optimum conditions was found in the order: Cu2+ > Fe3+ > Ni2+ > Co2+ > Mn2+ > Zn2+. Stability studies of the iminodiacetate ligand system showed that a degradation of the siloxane network and leaching of some species occurred upon treatment with strong acid and base aqueous solutions.