Polyethylenimine as a Non-Innocent Ligand for Hexacyanoferrates Immobilization

Abstract

To understand how polyethyleneimine (PEI), as a ligand, affects structure and properties of the transition metals hexacyanoferrates (HCFs) immobilized in cross-linked PEI matrix, we have synthesized Cu(II), Zn(II), and Fe(III) HCFs via successive ion-exchange reactions with metal salts and K4[FeII(CN)6] or K3[FeIII(CN)6]. The structure and properties of the obtained materials in comparison with the crystalline HCF analogs were investigated with FT-IR, Mössbauer, and UV–Vis spectroscopy. Complete reduction of Fe(III) to Fe(II) by PEI in HCF(III) was confirmed. When synthesis was performed at pH favoring binding of precursor metal ions by PEI, cyano-bridged hybrids rather than polymer—HCFs composites were formed. Although the obtained hybrids did not demonstrate sorption activity toward cesium ions, known for crystalline HCFs, they are of interest for the other applications. SQUID measurements revealed a significant difference in magnetic properties of PEI–HCFs hybrids in comparison with crystalline HCFs. Due to the Fe(III) to Fe(II) reduction in HCF ions, Cu(II) and Fe(III) HCFs(III) lost the molecular magnets properties in PEI matrix, but magnetic ordering, including ferromagnet-antiferromagnet interactions, was observed in all hybrids over the broad temperature range.

Short-Term Stability of Electrochemical Properties of Layer-by-Layer Coated Heterogeneous Ion Exchange Membranes

“…Polyallylamine is used for layer-by-layer assembly [ 39 ] as a component of new promising materials (such as thermo-responsive polymers with cleavage-induced phase transition [ 40 ] or coatings decomposing by application of electric potential [ 41 ]), including biomedical applications such as creation of nano-capsules for drug delivery [ 42 ] and food packaging [ 43 ]. Polyethylenimine is frequently used as a polymer carrier [ 44 ] and basis for loading of nanoparticles [ 45 ] or coating for medical applications [ 46 ]. However, its use in biomedical application is shaped by the cyto-staticity [ 47 ] or cytotoxicity of amine groups which simultaneously makes it non-biocompatible [ 48 ] and useful as antimicrobial and anticancer agent [ 49 , 50 ].…”