ISSN 1070-4272, Russian Journal of Applied Chemistry, 2014, Vol. 87, No. 7, pp. 923−929. © Pleiades Publishing, Ltd., 2014.
Original Russian Text © L.K. Neudachina, A.Ya. Golub, A.S. Kholmogorova, 2014, published in Zhurnal Prikladnoi Khimii, 2014, Vol. 87, No. 7, pp. 920−927.
OF SYSTEMS AND PROCESSES
Extremely low concentrations of precious metals in the
analyzed samples along with a multicomponent matrix of
a sample containing macroquantities of elements, which
accompany platinoids, stipulate an introduction into the
analysis scheme of a stage of concentrating metals of
Multi-component samples and the similarity of the
chemical properties of the platinum metals require previ-
ous separation them from each other
Organopolymeric ion exchange and complexing sor-
bents, which are of a low thermal stability, high chemical
activity of the matrix, high swelling capacity, limited
availability of functional groups, are often used for sorp-
tion concentrating of palladium [1–9].
There is a lot of work on sorption recovery of pal-
ladium with silica covalently modiﬁ ed with organic
chelating groups [10, 11]. In this case all the functional
groups are available on the surface of the sorbent matrix.
Usually structural-adsorption characteristics of the origi-
nal silica are kept.
Polysiloxanes obtained by a joint polycondensation
of organosilicon compounds with tetraethoxysilane
(sol-gel method) in the presence of precursors ensuring
the formation of chelating groups of given composition
in the structure of the sorbent, are promising sorbents
for the extraction of metals of the platinum groups. In
[12, 13] conditions of platinum extraction with amino-
propyl polysiloxane and also polysiloxane modiﬁ ed
thiourea were studied in detail. Conditions of separation
of platinum from ions of base metals were found. Earlier
sorption of palladium on such materials has not been
The aim of the study was investigation of sorption of
palladium(II) from model solutions with aminopropyl
polysiloxane (APPS) and polysiloxane modiﬁ ed
thiourea groups (PSMT).
Synthesis and identiﬁ cation
of sorbents were described
previously in . (3-Aminopropyl)triethoxysilane (AP-
TES, 98%, Sigma-Aldrich) and tetraethoxysilane (TEOS,
Acrosorganics) were used as starting materials for
the synthesis of adsorbents. The state standard (GSO
8432) was used to prepare the solution of palladium(II).
Sorption of palladium was studied under continuous
stirring by an agitator PE-6410M (Ekros) equipped with
the heated platform and a controller of the oscillation
frequency in the static mode by a method of separate por-
Sorption Extraction of Palladium(II) with Modiﬁ ed Polysiloxane
L. K. Neudachina, A. Ya. Golub, and A. S. Kholmogorova
Ural Federal University named after the ﬁ rst President of Russia B.N. Yeltsin,
ul. Mira 19, Yekaterinburg, 620002 Russia
Received May 27, 2014
Abstract—Sorption of palladium(II) from model solutions with polysiloxanes modiﬁ ed with amine and thiourea
groups was stidied and it was found that the maximum sorption on aminopropyl polysiloxane is shifted slightly
to alkaline region compared with a sulfur-containing sorbent. First time an effect of a series of external factors
on a sorption kinetics of palladium with polysiloxanes was researched, diffusion coefﬁ cients of sorbate ions were
calculated, and evaluation of their dependence on an initial concentration of metal, a grain diameter of the sorbent,
and a temperature of sorption environment was carried out. It is shown that quantitative desorption of palladium
from thiocarbamoylated polysiloxane is achieved by double treating the sorbent with hydrochloric acid solution
of thiourea at high temperature.