Acid-base and complexation properties of surface of the aminated carbons various types

Abstract

The purposes of this investigation – are synthesis of the carbon sorbents, containing connected with
each other amino and carboxyl groups, study of their protolytic properties and complexation. The synthesis
was carried out using sorbents surface build on the pre-aminated carbon «БАУ-А». The structure, the acidbase
properties and the complexation were investigated by IR spectroscopy, Boehm titration, potentiometric
titration and sorption experiments. The sorption relations was processed using known models.
The centers with pKa value of 3 and 4 was found on the investigated sorbents surface. This indicates
the presence of amino- and carboxyl groups associated with each other in α-position. The surface complexes
of the 1: 1 and 1: 2 detected when studying the copper (II), iron (III), cadmium (II) and manganese (II)
sorption. Conditional complexation constants of the investigated carbons with the manganese and the
cadmium ions is higher than that of the unmodified activated carbon. This enables us to apply these sorbents
for the metals extraction from solutions with low pH.