Selective adsorption of silver(I) ions over copper(II) ions on a sulfoethyl derivative of chitosan.
This study presents a simple and effective method of preparation of N-(2-sulfoethyl) chitosan (NSE-chitosan) that allows obtaining a product with a degree of modification up to 1.0. The chemical structure of the obtained polymers was confirmed by FT-IR and 1H NMR spectroscopies. Cross-linking of N-(2-sulfoethyl) chitosans by glutaraldehyde allows preparation of sorbents for removal and concentration of metal ions. Capacity of sorbents towards hydroxide ions was determined depending on the degree of sulfoethylation under static and dynamic conditions. Dissociation constants of functional amino groups of the analyzed sorbents were determined by potentiometric titration. It was shown that basicity of the amino groups decreased (wherein pKa decreased from 6.53 to 5.67) with increase in degree of sulfoethylation. It explains the significant influence of sulfo groups on selectivity of sorption of metal ions on N-(2-sulfoethyl) chitosan-based sorbents. The investigated substances selectively remove copper(II) and silver(I) ions from solutions of complex composition. Wherein the selectivity coefficient KAg/Cu increased to 20 (pH 6.5, ammonium acetate buffer solution) with increase in degree of sulfoethylation of the sorbent up to 1.0.
Ural Federal University named after the first President of Russia B.N. Yeltsin, 19 Mira St., 620002 Yekaterinburg, Russia. Electronic address: petrova.yu.s@mail.ru.
Yulia S
YS
Petrova
Ural Federal University named after the first President of Russia B.N. Yeltsin, 19 Mira St., 620002 Yekaterinburg, Russia; I. Ya. Postovsky Institute of Organic Synthesis, Ural Division of Russian Academy of Sciences, 22 Kovaleskoy St., 620990 Yekaterinburg, Russia.
Alexandr V
AV
Pestov
Ural Federal University named after the first President of Russia B.N. Yeltsin, 19 Mira St., 620002 Yekaterinburg, Russia.
Maria K
MK
Usoltseva
Ural Federal University named after the first President of Russia B.N. Yeltsin, 19 Mira St., 620002 Yekaterinburg, Russia.
Ludmila K
LK
Neudachina
D000327:Adsorption; D048271:Chitosan / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D066244:Proton Magnetic Resonance Spectroscopy; D012834:Silver / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
D012834:Silver; D003300:Copper; D048271:Chitosan
Chitosan; Selectivity; Silver(I); Sorption; Sulfoderivatives