Synthesis and properties of some transition metal complexes with water soluble hydroxy functionalized polyacrylonitrile

Polyacrylonitrile (PAN) was converted to polyacrylonitrile-monoethanolamine (PAN-MEA), through reaction with 2-aminoethanol (MEA) in a simple and one step method. The obtained polymer was hydrosoluble and hydroxy-functionalized. The polymer-metal complexes were prepared in an aqueous solution in different pHs via two different methods, namely precipitation and dialysis tube. In all cases, increasing the pH values raised metal sorption capacities of PAN-MEA. The maximum metal sorption capacity was obtained for Fe(III) at pH 3 with 100.7 mg and the minimum for Ni(II) at pH 2 with 22.34 mg per one gram PAN-MEA metal complex. The selectivity of polymer for the adsorption of Fe(III) is greater than that of Cu(II) in the mixture of these ions and in the mixture of Zn(II) and Ni(II) the adsorption is greater for Zn(II). FTIR Spectra of polymer-metal complexes showed wavenumber shifts due to metal complex formation. UV-Vis spectroscopy studies showed the presence of metal ions in polymer-metal complexes due to the absorption in the region between 400 nm to 800 nm. Also, thermal gravimetry analysis of polymer-metal complexes confirmed the presence of metal in the final polymer complexes.