Mössbauer spectroscopic investigation of the sorption of iron by polyether-type polyurethane-foam sorbents

Abstract

The results of a study on the nature of the iron species sorbed by polyether-type open-cell polyurethane (PU) foam membranes are presented. The study has included freshly prepared anionic ⁵⁷Fe^III–halo complexes and ⁵⁷Fe(SCN)₃, in addition to the cationic ⁵⁷Fe^II–phenanthroline complex. Conclusions concerning the most probable nature of the sorbed species have been drawn from the comparison of Mössbauer spectra for frozen Fe—PU foam complexes with the spectra for corresponding iron-containing frozen aqueous solutions and extracts in suitable organic solvents. For Fe^III compounds, diethyl ether, and for the Fe^II complex, acetone, pentyl alcohol and nitrobenzene were used as organic solvents. The spectra were recorded at 80 K and evaluated to obtain isomer shifts, quadrupole splittings and internal magnetic fields for different iron species.