Volume 41 - Issue 3 - 207 - 219

Complexation of Zn2+ with Vinyl Imidazole Containing IMAC Adsorbent: Potentiometric, Kinetic, and Thermodynamic Studies

Vinil İmidazol İçeren IMAK Adsorbanının Zn2+ ile Kompleksleşmesi: Potansiyometrik, Kinetik ve Termodinamik Çalışmalar

The aim of this paper is to synthesize a cross-linked polymer containing imidazole groups and study its metal ion complex properties under different experimental conditions. Thus, the use of the potentiometric method for the determination of the protonation constant of vinyl imidazole (VIM) and the stability constant of the Zn2+ ion complex of VIM was investigated. First to determine the coordination tendency of the vinyl imidazole ligand towards the Zn2+ ions in solution, poly(ethylene glycol dimethacrylate-n-vinyl imidazole) [poly(EGDMA– VIM)] microbeads (average diameter 150–200 μm) were synthesized. The microbeads were characterized by N2 adsorption/desorption isotherms, elemental analysis, energy dispersive spectroscopy (EDS or EDX). Protonation constants of vinyl imidazole and the metal-ligand stability constant of vinyl imidazole with Zn2+ ions have been determined potentiometrically in a 0.1 M NaCl medium at 298, 318, and 338 K. The corresponding thermodynamic parameters of protonation and complexation processes (ΔG, ΔH, and ΔS) were derived and discussed. The formation kinetics of Zn2+-vinyl imidazole complex were also investigated, and the process obeyed the pseudo-second-order kinetic model. 

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