Russian Journal of Applied Chemistry, 2013, Vol. 86, No. 9, pp. 1383−1387.
Pleiades Publishing, Ltd., 2013.
Original Russian Text © N.V. Lakiza, O.I. Tissen, L.K. Neudachina, M.A. Ezhikova, M.I. Kodess, A.V. Pestov, 2013, published in Zhurnal Prikladnoi Khimii,
2013, Vol. 86, No. 9, pp. 1414−1418.
Preparation of a Chelating Sorbent Based
on Pyridylethylated Polyethylenimine
for Recovering Transition Metal Ions
N. V. Lakiza
, O. I. Tissen
, L. K. Neudachina
M. A. Ezhikova
, M. I. Kodess
, and A. V. Pestov
Yeltsin Ural Federal University, Yekaterinburg, Russia
Postovskii Institute of Organic Synthesis, Ural Branch, Russian Academy of Sciences, Yekaterinburg, Russia
Received July 30, 2013
Abstract—A method was developed for preparing a chelating amino polymer, pyridylethylpolyethylenimine with
maximal degree of substitution, by polymer-analogous transformations of branched polyethylenimine in reaction
with 2-vinylpyridine. The ability of cross-linked pyridylethylpolyethylenimine with the degree of substitution of
0.32 to sorb Cu
, and Pb
ions present simultaneously in solution was evaluated.
In an ammonium acetate sorption system (pH 3.5–4.0), the sorbent selectively interacts with Cu(II) ions.
Polymer-analogous transformations of macromo-
lecular compounds allow the application ﬁ elds of known
and available polymeric materials to be considerably
expanded. Polyethylenimine (PEI) is a commercially
available and highly reactive polymeric matrix. The PEI
reactivity is determined by its polybase properties caused
by the presence of primary, secondary, and tertiary amino
groups. In most cases, their ratio is 1 : 2 : 1 , but it
strongly depends on the polymerization conditions:
The polybase nature of PEI ensures high ability of the
macromolecule to form complexes with transition metal
ions . Sorbents can be jprepared both from unmodi-
ﬁ ed cross-linked PEI [3–6] and from the functionalized
polymer [6–12]. PEI as a polyamine is highly active in
sorption of Hg(II) (3.3 mmol g
), Cu(II), Ni(II),
Co(II), and Zn(II) ions (no less than 2 mmol g
in combination with chitosan, in sorption of Hg(II) ,
Pt(IV), and Pd(II) ions . Such complexing proper-
ties of PEI allow preparation of structure-forming [13,
14] and metal-containing catalytic  materials based
on it. Additional N-functionalization of PEI, primarily
occurring at the most reactive primary amino groups
, signiﬁ cantly alters the sorption characteristics. For
example, at pH < 2, the sorption capacity of PEI-based
sorbents containing carboxylic acid residues for Cu
is 0.7 mmol g
[7, 8]. The sorbent prepared by introduc-
tion of the 2,3-dihydroxypropyl substituent exhibits high
ability to sorb boric acid (>2 mmol g
) [9, 10].
In this study, we developed a procedure for PEI
pyridylethylation, prepared sorption materials from the
modiﬁ ed polymer, and evaluated their ability to sorb a
series of transition metal ions.
We used commercial branched polyethylenimine
(Aldrich) with the average molecular weight of 25 kDa.
2-Vinylpyridine (Sigma–Aldrich) was distilled before
use and stabilized with hydroquinone (0.05%). C,H,N
analysis was performed with a Perkin–Elmer automatic
analyzer. The IR reﬂ ection spectra were recorded with a
Spectrum One spectrophotometer (Perkin–Elmer). The