ISSN 1070-4272, Russian Journal of Applied Chemistry, 2006, Vol. 79, No. 2, pp. 225!228. + Pleiades Publishing, Inc., 2006.
Original Russian Text + A. M. Akimbaeva, E. E. Ergozhin, 2006, published in Zhurnal Prikladnoi Khimii, 2006, Vol. 79, No. 2, pp. 226!229.
AND ION-EXCHANGE PROCESSES
Bentonite-based Phosphoric Acid Organomineral Cationite
A. M. Akimbaeva and E. E. Ergozhin
Bekturov Institute of Chemical Sciences, Ministry of Education and Science of the Republic of Kazakhstan,
Received March 31, 2005
Abstract-The conditions under which bentonite-based phosphoric acid organomineral cationite is obtained
were assessed and its acid-base and physicochemical properties were studied.
Until recently, synthetic organic polymers with
ionogenic functional groups containing inorganic sub-
stances (silica, aluminum oxide, zeolites) have con-
stituted two main classes of ion-exchangers. The wide
use of organopolymer sorbents is due to the versatility
oftheir action, ease of regeneration, and possibility of
widely varying the nature and content of functional
groups. The advantages of inorganic ionites include
the nonswellability in solvents, mechanical strength,
thermal stability, radiation hardness, and, in some
cases, unique catalytic properties. Combination of
the valuable properties of both classes of sorbents
enables development of few-stage methods for syn-
thesis of new effective ion-exchangers with a set of
valuable properties. In this context, a necessity arises
for creating a new type of materials combining the ad-
vantages of these ion exchangers. The materials are
obtained by modifying the surface of inorganic sub-
stances with organic compounds containing func-
tionally active groups . Of particular importance
among these materials are phosphorus-containing
organomineral ion-exchangers with a silica matrix,
which are used in sorption, concentration, and various
types of chromatography [1, 2]. A promising solution
in this area is to use natural raw materials and various
kinds of industrial waste .
The aim of the present study was to synthesize
a phosphoric acid organomineral cationite based on
Bentonite (Bt), whose main rock-forming mineral
is montmorillonite, served as a mineral support.
The acid activation of the natural sorbent was done in
on a boiling water bath in the course of
6 h .
After distillation, glycidyl methacrylate (GMA) had
the following parameters: d
= 1.0333, n
Slime orthophosphoric acid (r = 1.588 g cm
taken from the waste of Zhambyl phosphorus plant
The mineral was modified with phosphoric acid in
dioxane, with the subsequent polymerization of GMA
at 100oC . Then cationite samples were converted
to the H-form and back, each time with
washing to a neutral reaction of the washing water.
The static exchange capacity SEC (mg-equiv g
the final products was determined with a 0.1 N KOH
The samples were subjected to potentiometric titra-
tion by the method of separate weighed portions.
The ionic strength was maintained by adding a certain
amount of the electrolyte (KCl). After equilibrium
between the cation exchanger and the solution was es-
tablished, the pH value was measured with an EV-74
ion meter equipped with glass and silver chloride.
The results of these measurements were used to plot
the curve of potentiometric titration as a graph of pH
versus the amount of the titrant.
To determine the chemical and thermal stability of
the cationite in the H-form, three weighed portions of
the ionite (each 1.0 g in terms of dry substance) were
placed in 250-ml round-bottom flasks. The first of
these was poured over with a 5 N H
(100 ml); the second, with a 5 N NaOH solution
(100 ml); and the third, with distilled water (100 ml);
after which all the samples were kept at room tem-