Structure and sorption properties of vinylpyridine ion exchangers of different hydrophilic nature,containing copper and silver,based on EPR data

EPR was used to establish the structure of Cu²⁺ coordination centers in macroporous cross-linked polyvinylpyridines in the presence of Ag⁺ ions. The influence of a change in the hydrophilic nature of the polymer matrix, of the concentration of sorbed copper and silver ions, and of the moisture content of the samples on the formation and distribution of different forms of copper complexes has been determined. It has been shown that in the case of competition between Ag⁺ and Cu²⁺ for the ligand groups of the ion exchanger the formation of Ag⁺ coordination centers predominates. The coordination centers of copper are partially destroyed by forming hydrate and solvate complexes which are easily removed from the ion-exchanger matrix. The analysis of the integral intensities of the EPR spectra has given a quantitative estimation of the change in the content of Cu²⁺ coordination centers in the ion-exchanger matrix.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 26, No. 4, pp. 462–468, July–August, 1990.