Kolomiets E. Morphological features and sorption properties of anion-exchange polymer-inorganic composites containing hydrated oxides of polyvalent metals

Сomposite sorbents, which are based on the polymer ion-exchange matrix and inorganic modifiers, were synthesized. The deposition method was used for obtaining the composites. Hydrated oxides of multivalent metals as Fe, Ti, Sn, Zr and their combinations (Fe-Sn, Zr-Fe) were selected as inorganic modifiers. A theoretical approach has been developed and experimentally verified, which allows to regulate the size of the incorporated particles in the porous matrix. The Ostwald-Freundlich equations were adapted to the process of precipitation of hydrated oxides for multivalent metals in anion-exchange polymer matrix. It was established that when precipitation of hydrated dioxide from organic solution occurs, the porous structure of polymer is reorganized and dendritic aggregates that were detected in hydrophobic pores are formed. Such aggregates are additional osmotic centers that stipulate compression of the hydrophilic pores. Because of this in the polymeric component of the formation of additional centers of selective sorption of anions: the ratio of capacities of the composite and the unmodificated resin exceeds 3 at an initial concentration of arsenate ions of 50 mg dm-3 in the presence of excess ions Cl–. The confirmation is the formation of such centers of compliance with the isothermal model of Dubinin-Radushkevich. As a result of the formation of unbroken chains of inorganic ion exchanger, the transfer of ions in such composites occurs not only in hydrophilic, but also in hydrophobic pores.