ELECTRICAL CONDUCTIVITY AND SORPTION PROPERTIES OF THE COMPOSITES BASED ON ION EXCHANGE POLYMERS

Abstract

The review is devoted to the conditions for the creation and functional properties of organіс-inorganic ion-exchange materials, which in the form of sorbents and membranes can be applied in the processes of ion separation, as well as the purification of water and combined solutions of technological origin. The structure of air dry and hydrated organic ion-exchange polymers, conditions for the creation of organiс-inorganic ion-exchange materials, as well as their components, interaction of components and the corresponding classification are considered. Dry ion-exchange materials contain heterogeneities of different sizes, which are formed during the synthesis of polymer, with the smallest heterogeneities represent clusters, and the larger ones are related to crystallinity. The structure of hydrated ion- exchange materials adequately describes the cluster channel model of Hsu and Girke. The number of charged particles transferred corresponds to the contribution of clusters and channels (volume fractions) to total porosity. The size of the clusters and channels can be determined by the method of small-angle X-ray scattering. The complex porous structure of ion-exchange polymers makes it possible to form inorganic particles in the one’s pores. The introduction of inorganic ion exchangers into the polymer leads to the appearance of additional osmotically active centers (fixed ions and antimony modifiers) that influence the compression pressure of composites. Regarding the functional properties of organiс-inorganic materials, data on the influence of the form and size of the nanoparticles of the inorganic component on the electrical conductivity of composites, examples of the use of organiс-inorganic sorbents in ion-exchange columns, and also effective diffusion coefficients corresponding to the exchange of two-charge metal cations (Zn2+, Pb2+, Cu2+, Ca2+, Ni2+) on H+ organic-inorganic sorbents, for the most part, organic resin- Dowex HCR-S with incorporated particles of zirconium hydrophosphate, are presented. The prospect of application of such materials in ion-exchange and membrane processes of separation and purification of aqueous solutions, as well as in the processes of efficient selective extraction of target ions, is shown.